Smurfit Westrock (SW) 10-Q8 Nov 242024 Q3 Quarterly reportFinancial data

Company Profile

Cover

Cover - shares	9 Months Ended
Cover - shares	Sep. 30, 2024	Nov. 05, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2024
Document Transition Report	false
Entity File Number	001-42161
Registrant Name	Smurfit Westrock plc
Entity Incorporation, State or Country Code	L2
Entity Tax Identification Number	98-1776979
Entity Address, Address Line One	Beech Hill, Clonskeagh
Entity Address, City or Town	Dublin 4
Entity Address, Postal Zip Code	D04 N2R2
Entity Address, Country	IE
City Area Code	+353
Local Phone Number	1 202 7000
Title of 12(b) Security	Ordinary shares, par value $0.001 per share
Trading Symbol	SW
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		520,156,112
Central Index Key	0002005951
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents, including restricted cash (amounts related to consolidated variable interest entities of $3 million and $3 million at September 30, 2024 and December 31, 2023, respectively)	$ 951	$ 1,000
Accounts receivable (amounts related to consolidated variable interest entities of $823 million and $816 million at September 30, 2024 and December 31, 2023, respectively)	4,613	1,806
Inventories	3,585	1,203
Other current assets	1,396	561
Total current assets	10,545	4,570
Property, plant and equipment, net	23,206	5,791
Goodwill	7,215	2,842
Intangibles, net	1,094	218
Prepaid pension asset	615	29
Other non-current assets (amounts related to consolidated variable interest entities of $390 million and $— million at September 30, 2024 and December 31, 2023, respectively)	2,354	601
Total assets	45,029	14,051
Current liabilities:
Accounts payable	3,357	1,728
Accrued expenses	813	278
Accrued compensation and benefits	954	438
Current portion of debt	745	78
Other current liabilities	1,257	484
Total current liabilities	7,126	3,006
Non-current debt due after one year (amounts related to consolidated variable interest entities of $337 million and $20 million at September 30, 2024 and December 31, 2023, respectively)	13,174	3,669
Deferred tax liabilities	3,682	280
Pension liabilities and other postretirement benefits, net of current portion	788	537
Other non-current liabilities (amounts related to consolidated variable interest entities of $334 million and $— at September 30, 2024 and December 31, 2023, respectively)	2,267	385
Total liabilities	27,037	7,877
Commitments and Contingencies (Note 17)
Equity:
Preferred stock; $0.001 par value; 500,000,000 and Nil shares authorized; 10,000 shares and Nil outstanding at September 30, 2024 and December 31, 2023, respectively	0	0
Common stock; $0.001 par value; 9,500,000,000 and 9,910,931,085 shares authorized; 520,056,084 and 260,354,342 shares outstanding at September 30, 2024 and December 31, 2023, respectively	1	0
Deferred shares, €1 par value; 25,000 shares and 25,000 shares authorized; 25,000 and 100 shares outstanding at September 30, 2024 and December 31, 2023, respectively	0	0
Treasury stock, at cost (2,037,589, and 1,907,129 common stock at September 30, 2024 and December 31, 2023 respectively)	(93)	(91)
Capital in excess of par value	15,890	3,575
Accumulated other comprehensive loss	(1,011)	(847)
Retained earnings	3,178	3,521
Total stockholders’ equity	17,965	6,158
Noncontrolling interests	27	16
Total equity	17,992	6,174	[1]
Total liabilities and equity	$ 45,029	$ 14,051

[1] Pursuant to the Transaction Agreement, on July 5, 2024 each issued ordinary share, par value €0.001 per share, of Smurfit Kappa (a “Smurfit Kappa Share”) was exchanged for one ordinary share, par value $0.001 per share, of Smurfit Westrock (a “Smurfit Westrock Share”). The exchange of shares is reflected retroactively to the earliest period presented.

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Statement [Abstract]
Net sales	$ 7,671	$ 2,915	$ 13,570	$ 9,231
Cost of goods sold	(6,321)	(2,173)	(10,817)	(6,878)
Gross profit	1,350	742	2,753	2,353
Selling, general and administrative expenses	(1,028)	(371)	(1,797)	(1,144)
Transaction and integration-related expenses associated with the Combination	(267)	(17)	(350)	(17)
Operating profit	55	354	606	1,192
Pension and other postretirement non-service benefit (expense), net	8	(9)	(31)	(29)
Interest expense, net	(167)	(39)	(225)	(109)
Other expense, net	(13)	(4)	(13)	(19)
(Loss) income before income taxes	(117)	302	337	1,035
Income tax expense	(33)	(73)	(164)	(258)
Net (loss) income	(150)	229	173	777
Less: Net (loss) income attributable to noncontrolling interests	0	0	0	0
Net (loss) income attributable to common stockholders	$ (150)	$ 229	$ 173	$ 777
Basic (loss) earnings per share attributable to common stockholders (in USD per share)	$ (0.30)	$ 0.89	$ 0.51	$ 3.01
Diluted (loss) earnings per share attributable to common stockholders (in USD per share)	$ (0.30)	$ 0.88	$ 0.50	$ 3

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive (Loss) Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (150)	$ 229	$ 173	$ 777
Foreign currency:
Foreign currency translation gain (loss)	86	(139)	(181)	119
Defined benefit pension and other postretirement benefit plans adjustments	(26)	25	14	11
Derivatives:
Deferred gain recognized on cash flow hedges	0	7	3	3
Other comprehensive income (loss), net of tax	60	(107)	(164)	133
Comprehensive (loss) income	(90)	122	9	910
Less: Comprehensive (loss) income attributable to noncontrolling interests	0	0	0	0
Comprehensive (loss) income attributable to common stockholders	$ (90)	$ 122	$ 9	$ 910

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Operating activities:
Net income	$ 173	$ 777
Adjustments to reconcile consolidated net income to net cash provided by operating activities:
Depreciation, depletion and amortization	872	430
Cash surrender value increase in excess of premiums paid	(14)	0
Share-based compensation expense	154	43
Deferred income tax benefit	(99)	(4)
Pension and other postretirement funding more than cost	(30)	(35)
Other	16	(4)
Change in operating assets and liabilities, net of acquisitions and divestitures:
Accounts receivable	(422)	63
Inventories	120	161
Other assets	(31)	21
Accounts payable	(226)	(438)
Income taxes	34	(46)
Accrued liabilities and other	155	(20)
Net cash provided by operating activities	702	948
Investing activities:
Capital expenditures	(897)	(661)
Cash paid for purchase of businesses, net of cash acquired	(716)	(29)
Proceeds from corporate owned life insurance	2	0
Proceeds from sale of property, plant and equipment	15	11
Other	1	2
Net cash used for investing activities	(1,595)	(677)
Financing activities:
Additions to debt	3,127	77
Repayments of debt	(1,640)	(120)
Debt issuance costs	(44)	0
Revolving credit facilities repayments, net	(4)	(4)
Changes in commercial paper, net	(33)	0
Other debt additions, net	17	0
Repayments of lease liabilities	(12)	(2)
Tax paid in connection with shares withheld from employees	(21)	0
Purchases of treasury stock	(27)	(30)
Cash dividends paid to stockholders	(493)	(299)
Other	(1)	0
Net cash provided by (used for) financing activities	869	(378)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(25)	(5)
Decrease in cash, cash equivalents and restricted cash	(49)	(112)
Cash, cash equivalents and restricted cash at beginning of period	951	729
Cash, cash equivalents and restricted cash at end of period	$ 1,000	$ 841

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Changes in Equity (Unaudited) - USD ($) $ in Millions		Total	Total Stockholders' Equity	Common Stock		Capital in Excess of Par value	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive Loss	Noncontrolling Interest ("NCI")
Beginning balance (in shares) at Dec. 31, 2022	[1]			259,000,000
Beginning balance at Dec. 31, 2022	[1]	$ 5,343	$ 5,328	$ 0		$ 3,528	$ (78)	$ 3,087	$ (1,209)	$ 15
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income		777	777					777
Other comprehensive income (loss), net of tax		133	133						133
Share-based payments		42	42			42
Issuance of common stock (in shares)				1,000,000
Shares distributed by Smurfit Kappa Employee Trust		0				(17)	17
Purchases of treasury stock		(30)	(30)				(30)
Dividends declared		(299)	(299)					(299)
Ending balance (in shares) at Sep. 30, 2023				260,000,000
Ending balance at Sep. 30, 2023		5,966	5,951	$ 0		3,553	(91)	3,565	(1,076)	15
Beginning balance (in shares) at Jun. 30, 2023	[2]			260,000,000
Beginning balance at Jun. 30, 2023	[2]	5,837	5,822	$ 0		3,547	(92)	3,336	(969)	15
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income		229	229					229
Other comprehensive income (loss), net of tax		(107)	(107)						(107)
Share-based payments		7	7			7
Shares distributed by Smurfit Kappa Employee Trust		0				(1)	1
Ending balance (in shares) at Sep. 30, 2023				260,000,000
Ending balance at Sep. 30, 2023		$ 5,966	5,951	$ 0		3,553	(91)	3,565	(1,076)	15
Beginning balance (in shares) at Dec. 31, 2023		260,354,342		260,000,000	[3]
Beginning balance at Dec. 31, 2023	[3]	$ 6,174	6,158	$ 0		3,575	(91)	3,521	(847)	16
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income		173	173					173
Other comprehensive income (loss), net of tax		(164)	(164)						(164)
Share-based payments		149	149			149
Shares distributed by Smurfit Kappa Employee Trust		0				(25)	25
Purchases of treasury stock		(27)	(27)				(27)
Shares of Smurfit Westrock common stock issued to WestRock stockholders and NCI assumed as a result of the Merger (in shares)				258,000,000
Shares of Smurfit Westrock common stock issued to WestRock stockholders and NCI assumed as a result of the Merger		12,110	12,099	$ 1		12,098				11
Converted WestRock RSUs and Options attributable to pre-Combination services		91	91			91
Issuance of common stock net of tax paid in connection with shares withheld from employees (in shares)				2,000,000
Issuance of common stock net of tax paid in connection with shares withheld from employees		(21)	(21)					(21)
Dividends declared	[4]	$ (493)	(493)			2		(495)
Ending balance (in shares) at Sep. 30, 2024		520,056,084		520,000,000
Ending balance at Sep. 30, 2024		$ 17,992	17,965	$ 1		15,890	(93)	3,178	(1,011)	27
Beginning balance (in shares) at Jun. 30, 2024	[2]			261,000,000
Beginning balance at Jun. 30, 2024	[2]	5,941	5,925	$ 0		3,580	(93)	3,509	(1,071)	16
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income		(150)	(150)					(150)
Other comprehensive income (loss), net of tax		60	60						60
Share-based payments		119	119			119
Shares of Smurfit Westrock common stock issued to WestRock stockholders and NCI assumed as a result of the Merger (in shares)				258,000,000
Shares of Smurfit Westrock common stock issued to WestRock stockholders and NCI assumed as a result of the Merger		12,110	12,099	$ 1		12,098				11
Converted WestRock RSUs and Options attributable to pre-Combination services		91	91			91
Issuance of common stock net of tax paid in connection with shares withheld from employees (in shares)				1,000,000
Issuance of common stock net of tax paid in connection with shares withheld from employees		(21)	(21)					(21)
Dividends declared	[5]	$ (158)	(158)			2		(160)
Ending balance (in shares) at Sep. 30, 2024		520,056,084		520,000,000
Ending balance at Sep. 30, 2024		$ 17,992	$ 17,965	$ 1		$ 15,890	$ (93)	$ 3,178	$ (1,011)	$ 27

[1] Pursuant to the Transaction Agreement, on July 5, 2024 each issued ordinary share, par value €0.001 per share, of Smurfit Kappa (a “Smurfit Kappa Share”) was exchanged for one ordinary share, par value $0.001 per share, of Smurfit Westrock (a “Smurfit Westrock Share”). The exchange of shares is reflected retroactively to the earliest period presented. P ursuant to the Transaction Agreement, on July 5, 2024 each issued ordinary share, par value €0.001 per share, of Smurfit Kappa (a “Smurfit Kappa Share”) was exchanged for one ordinary share, par value $0.001 per share, of Smurfit Westrock (a “Smurfit Westrock Share”). The exchange of shares is reflected retroactively to the earliest period presented. Pursuant to the Transaction Agreement, on July 5, 2024 each issued ordinary share, par value €0.001 per share, of Smurfit Kappa (a “Smurfit Kappa Share”) was exchanged for one ordinary share, par value $0.001 per share, of Smurfit Westrock (a “Smurfit Westrock Share”). The exchange of shares is reflected retroactively to the earliest period presented. Includes cash dividends and dividend equivalent units declared on certain unvested s hare-base d payment awards. Includes cash dividends and dividend equivalent units declared on certain unvested share- based payment awards.

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) $ in Millions	Sep. 30, 2024 USD ($) $ / shares shares	Sep. 30, 2024 € / shares	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2023 € / shares
Cash and cash equivalents, including restricted cash	$ 951		$ 1,000
Accounts receivable	4,613		1,806
Other non-current assets	2,354		601
Non-current debt due after one year	13,174		3,669
Other non-current liabilities	$ 2,267		$ 385
Preferred stock, par or stated value per share (in euro per share) \| $ / shares	$ 0.001		$ 0.001
Preferred stock, shares authorized (in shares) \| shares	500,000,000		0
Preferred stock, shares outstanding (in shares) \| shares	10,000		0
Common stock, par or stated value per share (in euro per share) \| $ / shares	$ 0.001		$ 0.001
Common stock, shares authorized (in shares) \| shares	9,500,000,000		9,910,931,085
Common stock, shares outstanding (in shares) \| shares	520,056,084		260,354,342
Deferred stock, par or stated value per share (in euro per share) \| € / shares		€ 1		€ 1
Deferred stock, shares authorized (in shares) \| shares	25,000		25,000
Deferred stock, shares outstanding (in shares) \| shares	25,000		100
Treasury stock, common (in shares) \| shares	2,037,589		1,907,129
Variable interest entity, primary beneficiary
Cash and cash equivalents, including restricted cash	$ 3		$ 3
Accounts receivable	823		816
Other non-current assets	390		0
Non-current debt due after one year	337		20
Other non-current liabilities	$ 334		$ 0

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Changes in Equity (Unaudited) (Parenthetical)	3 Months Ended	9 Months Ended
	Sep. 30, 2024 $ / shares	Sep. 30, 2024 $ / shares	Sep. 30, 2023 $ / shares
Dividends per share, declared (USD per share)	$ 0.30	$ 0.95	$ 1.15
Common stock, par value (in euro/USD per share)	$ 0.001	$ 0.001

Description of Business and Sum

Description of Business and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Description of Business and Summary of Significant Accounting Policies	1.1. Description of Business Unless the context otherwise requires, or unless indicated otherwise,“we”, “us”, “our”, “Smurfit Westrock” and “the Company” refer to the business of Smurfit Westrock plc , its wholly-owned subsidiaries and its partially-owned consolidated subsidiaries. Smurfit Westrock plc (formerly known as Cepheidway Limited and Smurfit WestRock Limited) is a company limited by shares that is incorporated in Ireland. On December 11, 2023, Smurfit Westrock changed its name to Smurfit WestRock Limited, and then on June 18, 2024, it re-registered as an Irish public limited company and was renamed Smurfit Westrock plc. We are a multinational provider of sustainable fiber-based paper and packaging solutions . We partner with our customers to provide differentiated, sustainable paper and packaging solutions that enhance our customers’ prospects of success in their markets. Our team members support customers around the world from our operating and business locations in North America, South America, Europe, Asia, Africa, and Australia . Pursuant to a transaction agreement dated as of September 12, 2023 (the “Transaction Agreement”), among Smurfit Westrock , Smurfit Kappa Group plc (“Smurfit Kappa”), WestRock Company ("WestRock") and Sun Merger Sub, LLC (“Merger Sub”) the following was completed (i) Smurfit Westrock acquired Smurfit Kappa by means of a scheme of arrangement under the Companies Act 2014 of Ireland (as amended) (the “Smurfit Kappa Share Exchange”) and (ii) Merger Sub merged with and into WestRock, with WestRock continuing as the surviving entity (the “Merger” and, together with the Smurfit Kappa Share Exchange, the “Combination”). The Combination closed on July 5, 2024 (the “Closing Date”). Upon the completion of the Combination, Smurfit Kappa and WestRock each became wholly owned subsidiaries of Smurfit Westrock. 1.2. Basis of Presentation Other than activities related to its formation and in anticipation of the Combination, Smurfit Westrock did not conduct any operations from its incorporation until completion of the Combination. Given the non-operational nature of Smurfit Westrock prior to the Combination, the Smurfit Kappa Share Exchange is not considered a business combination and does not give rise to any goodwill or adjustments to accounting basis. The c onsolidated financial statements of Smurfit Westrock following the Smurfit Kappa Share Exchange are a continuation of the financial statements of Smurfit Kappa. The comparative financial information presented in these Condensed Consolidated Financial Statements reflect the pre-Combination carrying values of Smurfit Kappa with the legal share capital retroactively adjusted to reflect the legal capital of Smurfit Westrock as the successor after giving effect to the Smurfit Kappa Share Exchange. The Merger is recognized as a business combination under Accounting Standards Codification (“ASC”) 805, “Business Combinations” (“ASC 805”). Smurfit Kappa was determined to be the accounting acquirer of WestRock . Accordingly, the financial statements reflected in these Condensed Consolidated Financial Statements include WestRock's financial position and results of operations for the period subsequent to the completion of the Combination on July 5, 2024. Refer to “Note 2. Acquisitions ” for additional information related to the accounting for the Combination. Following the completion of the Combination, we reassessed our reportable segments due to changes in our organizational structure and how our chief operating decision maker (“CODM”) makes key operating decisions, allocates resources and assesses the performance of our business. Consequently, subsequent to the Combination, we began to manage the combined business as three reportable segments: (1) Europe, the Middle East and Africa (“MEA”), and Asia-Pacific (“APAC”), (2) North America, and (3) Latin America (“LATAM”). 1. Description of Business and Summary of Significant Accounting Policies - continued 1.2. Basis of Presentation - continued As a result of the change in reportable segments, prior year amounts have been recast to conform to the current year presentation. Throughout this Quarterly Report on Form 10-Q, amounts and activity reflect reclassifications related to the Company's change in reportable segments. The change in reportable segments had no impact on the Company’s Condensed Consolidated Balance Sheets, Condensed Consolidated Statements of Operations , Condensed Consolidated Statements of Comprehensive (Loss) Income , Condensed Consolidated Statements of Cash Flows and Condensed Consolidated Statements of Changes in Equity previously reported. Refer to “Note 3. Segment Information ”, for further discussion of the Company’s segment reporting structure. We derived the Condensed Consolidated Balance Sheet as of December 31, 2023 from the audited Consolidated Financial Statements of Smurfit Kappa for the year ended December 31, 2023 (the “2023 Consolidated Financial Statements”) included in the Proxy Statement/Prospectus of Smurfit Westrock dated April 26, 2024 (file number 333-278185). In the opinion of Smurfit Westrock’s management , all normal recurring adjustments necessary for the fair statement of the Consolidated Financial Statements have been included for the interim periods reported. The interim financial statements have been prepared in accordance with accounting principles generally accepted in the U.S. (“GAAP”) for interim financial information and with Article 10 of Regulation S-X of the Securities and Exchange Commission (“SEC”). Accordingly, they omit certain notes and other information from the 2023 Consolidated Financial Statements. Therefore, these interim financial statements should be read in conjunction with the 2023 Consolidated Financial Statements. The results for the three and nine months ended September 30, 2024 are not necessarily indicative of results that may be expected for the full year. The preparation of the Condensed Consolidated Financial Statements requires management to make certain estimates and assumptions about future events. These estimates and the underlying assumptions affect the amounts of assets and liabilities reported, disclosures about contingent assets and liabilities and reported amounts of revenues and expenses. Such estimates include fair value of acquired assets and assumed liabilities, goodwill impairment, income taxes and pension and other postretirement benefits. These estimates and assumptions are based on management’s judgment. Actual results may differ from those estimates, and the differences could be material. Estimates and underlying assumptions are reviewed on an ongoing basis. Changes in accounting estimates may be necessary if there are changes in the circumstances or experiences on which the estimate was based or as a result of new information. Changes in estimates, including those resulting from changes in the economic environment, are reflected in the period in which the change in estimate occurs. Due to rounding, numbers presented throughout this document may not add up precisely to the totals provided and percentages may not precisely reflect the absolute figures. Following the Combination, certain reclassifications have been made to the prior year amounts to conform to the current year presentation. These reclassifications include reclassifications within our segments, as described above. On completion of the Merger, as part of the harmonization of accounting policies, a disclosure reclassification of amounts previously classified as 'other postretirement benefit plans' took place with the plans now being classified and disclosed as 'defined benefit pension plans'. The prior year disclosure information in “Note 15. Retirement Plans ” has been updated to conform to the current year presentation. 1.3. Significant Accounting Policies There have been no changes to the Company’s significant accounting policies as described in “Note 1. Description of Business and Summary of Significant Accounting Policies ” in the 2023 Consolidated Financial Statements, other than updates to policies as a result of the Merger as described below. 1.4. Revenue Recognition The Company's revenue is primarily derived from the sale of containerboard, corrugated containers and other paper-based packaging products. All revenue relates to revenue from contracts with customers. Contracts with customers include a single performance obligation to sell these products and do not generally contain multiple performance obligations. We recognize revenue on a point-in-time basis when the customer takes title to the goods and assumes the risks and rewards for the goods, which coincides with the transfer of control of our goods to the customer upon delivery. Additionally, we manufacture certain customized products that have no alternative use to us (since they are made to specific customer specifications), and we believe that for certain customers we have a legally enforceable right to payment for performance completed to date on these products, including a reasonable profit. For products that meet these two criteria, we recognize revenue over time . This results in revenue recognition prior to the date of shipment or title transfer for these products and results in the recognition of a contract asset (unbilled receivables) with a corresponding reduction in finished goods inventory on our Condensed Consolidated Balance Sheets . Revenue is measured as the amount of consideration we expect to receive in exchange for transferring goods and is derived primarily from fixed consideration. Certain contracts may also include variable consideration, typically in the form of volume-based rebates and early settlement discounts. If a contract with a customer includes variable consideration, we estimate the expected impact based on historical experience and net the provisions for volume-based rebates, early settlement discounts and other adjustments against our gross sales. We concluded this method is consistent with the most likely amount method under ASC 606, “Revenue from Contracts with Customers” (“ASC 606”) and allows us to make the best estimate of the consideration we will be entitled to from customers. As permitted by ASC 606, we have elected to treat costs associated with obtaining new contracts as expenses when incurred if the amortization period of the asset we would recognize is one year or less. We do not record interest income when the difference in timing of control transfer and customer payment is one year or less. No element of financing is deemed present as the sales are made with credit terms consistent with market practice and are in line with normal credit terms in the entities’ country of operation. We also account for sales and other taxes that are imposed on and concurrent with individual revenue-producing transactions between a customer and us on a net basis which excludes the taxes from our net sales . 1.5. Fair Value of Financial Instruments and Nonfinancial Assets and Liabilities We estimate fair values in accordance with ASC 820 “Fair Value Measurement” (“ASC 820”). ASC 820 provides a framework for measuring fair value and expands disclosures required about fair value measurements. Specifically, ASC 820 sets forth a definition of fair value and a hierarchy prioritizing the inputs to valuation techniques. ASC 820 defines fair value as the price that would be received from the sale of an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Additionally, ASC 820 defines levels within the hierarchy based on the availability of quoted prices for identical items in active markets, similar items in active or inactive markets and valuation techniques using observable and unobservable inputs. We incorporate credit valuation adjustments to reflect both our own nonperformance risk and the respective counterparty’s nonperformance risk in our fair value measurements. The hierarchy consists of: • Level 1: fair value measurements represent exchange-traded securities, which are valued at quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access as of the reporting date; • Level 2: fair value measurements are determined using input prices that are directly observable for the asset or liability or indirectly observable through corroboration with observable market data; and • Level 3: fair value measurements are determined using unobservable inputs, such as internally developed pricing models for the asset or liability due to little or no market activity for the asset or liability. 1. Description of Business and Summary of Significant Accounting Policies - continued 1.5. Fair Value of Financial Instruments and Nonfinancial Assets and Liabilities - continued Financial instruments not recognized at fair value on a recurring or nonrecurring basis include cash and cash equivalents, accounts receivable , certain other current assets, short-term debt, accounts payable, certain other current liabilities and non-current debt. With the exception of non-current debt, the carrying amounts of these financial instruments approximate their fair values due to their short maturities. The fair value of debt such as debentures and various notes are based on quoted market prices as of the balance sheet date. The fair value of the revolving credit facility approximates its carrying value due to the nature of the repricing and interest based on variable rates. Following the Combination, w e have financial instruments recognized at fair value including supplemental retirement savings plans (“Supplemental Plans”) that are nonqualified deferred compensation plans pursuant to which assets are invested primarily in mutual funds, interest rate derivatives, commodity derivatives or other similar class of assets or liabilities. Assets and liabilities held in respect of these Supplemental Plans were $181 million and $168 million , respectively, as of September 30, 2024. We measure the fair value of our mutual fund investments based on quoted prices in active markets. Additionally, we measure our derivative contracts, if any, based on observable inputs such as interest rates, yield curves, spot and future commodity prices, and spot and future exchange rates . We discuss fair values in more detail in “Note 10. Fair Value Measurement ”. 1.6. Supplier Finance Program Obligations We maintain supplier finance programs whereby we have entered into payment processing agreements with certain financial institutions. These agreements allow participating suppliers to track payment obligations from Smurfit Westrock , and if voluntarily elected by the supplier, to sell payment obligations from Smurfit Westrock to financial institutions at a discounted price. We are not a party to the agreements between the participating financial institutions and the suppliers in connection with the program, and we do not reimburse suppliers for any costs they incur for participation in the program. We have not pledged any assets as security or provided any guarantees as part of the programs. We have no economic interest in our suppliers’ decisions to participate in the programs. Our responsibility is limited to making payment in full to the respective financial institution according to the terms originally negotiated with the supplier, which generally do not exceed 120 days . Smurfit Westrock or the financial institutions may terminate the agreements upon 30 or 90 days’ notice. Following the Combination, we assumed outstanding payment obligations to financial institutions and the outstanding payment obligations under these programs were $432 million as of September 30, 2024 . These obligations are classified as accounts payable within the Condensed Consolidated Balance Sheet s . 1.7. New Accounting Standards Not Yet Adopted In November 2023, the FASB issued ASU 2023-07, “Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures.” This ASU requires an entity to disclose incremental segment information, including enhanced disclosures about significant segment expenses. ASU 2023-07 is effective for the Company’s annual reporting periods beginning after December 15, 2023 and for interim periods beginning after December 15, 2024. Adoption is a fully retrospective method of transition. Early adoption is permitted. The Company is currently evaluating the effect that adoption of ASU 2023-07 will have on its Consolidated Financial Statements. In December 2023, the FASB issued ASU 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures.” This ASU requires the annual financial statements to include consistent categories and greater disaggregation of information in the rate reconciliation, and income taxes paid disaggregated by jurisdiction. ASU 2023-09 is effective for the Company’s annual reporting periods beginning after December 15, 2024. Adoption is either with a prospective method or a fully retrospective method of transition. Early adoption is permitted. The Company is currently evaluating the effect that adoption of ASU 2023-09 will have on its Consolidated Financial Statements.

Acquisitions

Acquisitions	9 Months Ended
Acquisitions	Sep. 30, 2024
Business Combination, Asset Acquisition, and Joint Venture Formation [Abstract]
Acquisitions	2. Acquisitions As referred to in “Note 1. Description of Business and Summary of Significant Accounting Policies - Description of the Business ”, on September 12, 2023, Smurfit Kappa and WestRock, a public company incorporated in Delaware, announced they had reached a definitive agreement on the terms of a proposed combination. The Combination closed on July 5, 2024. Pursuant to the Transaction Agreement, on the Closing Date each issued ordinary share, par value €0.001 per share, of Smurfit Kappa (a “Smurfit Kappa Share”) was exchanged for one ordinary share, par value $0.001 per share, of Smurfit Westrock (a “Smurfit Westrock Share”) and, in exchange for the net assets of WestRock acquired through the Merger, each share of common stock, par value $0.01 per share, of WestRock (the “WestRock Common Stock”), was converted into the right to receive one Smurfit Westrock Share and $5.00 in cash (the “Merger Consideration”) for an aggregate cash consideration of $1,291 million (the “Cash Consideration”) and issuance of 258,228,403 shares to WestRock shareholders.  Upon completion of the Combination, Smurfit Kappa and WestRock each became wholly owned subsidiaries of Smurfit Westrock with Smurfit Kappa shareholders owning approximately 50.3% and WestRock shareholders owning approximately 49.7% .    The Company expects the Combination to result in a global leadership position in sustainable packaging, characterized by quality, product, and geographic diversity.  In connection with the Combination, on April 3, 2024, Smurfit Kappa Treasury (a wholly owned subsidiary of Smurfit Westrock plc) completed an offering in the aggregate principal amount of $2,750 million of senior unsecured notes in three series, comprised of the following: $750 million aggregate principal amount of 5.200% senior notes due 2030 (the “2030 Notes”), $1,000 million aggregate principal amount of 5.438% senior notes due 2034 (the “2034 Notes”) and $1,000 million aggregate principal amount of 5.777% senior notes due 2054 (the “2054 Notes” and, together with the 2030 Notes and 2034 Notes, the “Notes” or the “Financing”) (such offering, the “Notes Offering”). A portion of the net proceeds of the Notes Offering was used to finance the Cash Consideration, fees, commissions, costs and expenses payable in connection with the Combination.  Merger Consideration  The following table summarizes the components of the aggregate M erger Consideration. T he amounts are calculated by reference to Smurfit Kappa’s share price of £36.56 on the Closing Date, translated to U.S. dollars using the closing exchange rate as of that date.  Cash paid for outstanding WestRock Stock (a) $ 1,291 Smurfit Westrock Shares issued to WestRock Stockholders (b) 12,098 Converted WestRock Options and WestRock RSU Awards attributable to pre-Combination service (c) 101 Settlement of pre-existing relationships, trade and other payable and receivable balances with WestRock (d) (29) Aggregate Merger Consideration $ 13,461 (a) The cash component of the aggregate Merger Consideration is ba sed on 258,228,403 shares of WestRock Stock multiplied by the Cash Consideration of $5.00 per WestRock shar e.   (b) Value of Smurfit Westrock Shares issued is based on 258,228,403 shares of outstanding WestRock Stock resulting in the issue of 258,228,403 Smurfit Westrock Shares at the closing share price of £36.56 on July 5, 2024, translated to U.S. dollars using the closing exchan ge rate of £1 to $1.2815 as of that date.  (c) Consideration for WestRock Options and WestRock restricted stock unit (“ RSU”) Awards replaced with Smurfit Westrock equity awards with similar terms, and the amount represents the consideration for their replacement. A portion of the fair value of Smurfit Westrock equity awards issued represents consideration transferred, while the remaining portion represents the post-Combination compensation expense based on the vesting terms of the converted awards. Also included , is the Merger Consideration in respect of WestRock Director RSU Awards, settled options held by former WestRock employees and vested and unreleased RSU awards all of which converted into WestRock Stock immediately prior to the Closing Date. (d) Component of Merger Consideration in respect of the settlement for no gain or loss of trade and other receivable and payable balances with WestRock as of the date of the Merger. The Merger Consideration has been increased by the amount of the settled Smurfit Kappa receivable of $3 million in respect of sales to WestRock and has been reduced to account for the effective settlement of accounts payable of $32 million in respect of trade and other purchases from WestRock. The WestRock receivable and payable in respect of these inter-company transactions were not recognized as an acquired asset or assumed liability. 2. Acquisitions - continued Preliminary Purchase Price Allocation  Smurfit Westrock management determined that Smurfit Kappa is the accounting acquirer in the Merger, which is accounted for under the acquisition method of accounting for business combinations in accordance with ASC 805.   T he preliminary allocation of the purchase pric e with respect to the Merger is based upon management’s estimates of and assumptions related to the fair values of WestRock assets acquired and liabilities assumed as of the Closing Date using currently available information. The excess of the purchase price over the fair value of net assets acquired has been allocated to goodwill.  The purchase price allocation for the Merger is preliminary and is subject to revision as additional information about the acquisition- date fair value of assets and liabilities becomes available . The Company is still evaluating the fair value of acquired property, plant and equipment, intangible assets and certain income tax related items in addition to ensuring all other assets and liabilities and contingencies have been identified and recorded. The Company has estimated the preliminary fair value of assets acquired and liabilities assumed based on information currently available and will continue to adjust those estimates during the measurement period (a period not to exceed 12 months from the Closing Date). Smurfit Westrock will reflect measurement period adjustments, if any, in the period in which the adjustments occur, and will finalize the accounting for the Merger within the measurement period. The prelimina ry allocation of the purchase price to the assets acquired and liabilities assumed, and a reconciliation to total consideration transferred is presented in the table below : Identifiable net assets: Cash and cash equivalents $ 603 Accounts receivable 2,374 Inventories 2,504 Other current assets 825 Property, plant and equipment 17,567 Intangibles 922 Prepaid pension asset 558 Other non-current assets 1,765 Accounts payable (2,018) Accrued compensation and benefits (447) Current portion of debt (1,285) Other current liabilities (1,123) Non-current debt due after one year (7,438) Deferred tax liabilities (3,523) Pension liabilities and other postretirement benefits, net of current portion (299) Other non-current liabilities (1,872) Noncontrolling interests (11) Identifiable net assets acquired as of July 5, 2024 9,102 Goodwill arising on Merger 4,359 Aggregate Merger Consideration $ 13,461 The goodwill arising from the Merger is attributable to the workforce of the acquired business and the significant synergies expected to arise after the Merger . Of the total goodwill recognized on the Merger, $3,990 million was allocated to the North American segment, $207 million was allocated to the LATAM segment and $162 million was allocated to the Europe, MEA and APAC segment. Of the total goodwill recognized, $187 million i s estimated to be deductible for tax purposes .   2. Acquisitions - continued The fair value of the assets acquired includes accounts receivable of $2,374 million that are not purchased financial assets with credit deterioration. The gross amount due under contracts was $2,429 million of which $55 million was expected to be uncollectible. Acquired other non-current assets includes a sales-type lease receivable and notes receivable with an aggregate fair value of $85 million . The gross amount due under contracts was $107 million , $22 million of which was expected to be uncollectible. The preliminary fair values of intangible assets were generally determined using income-based methods. The income method used for customer relationship intangibles is the multi-period excess earnings method based on forecasts of the expected future cash flows attributable to those assets. The relief from royalty method which the Company has used for the valuation of trade name and certain technology intangibles, estimates fair value by reference to the royalties saved through ownership of the trade name rather than paying a rent or royalty for its use. The fair value of certain technology-based intangibles was determined using a cost savings approach that measures the value of an asset by estimating the cost savings achieved through owning the asset.   Significant estimates and assumptions inherent in the valuations reflect consideration of other market participants, the amount and timing of future cash flows (including expected growth rates, discount rates, cost savings and profitability), royalty rates used in the relief from royalty method, and the discount rate applied to the cash flows. Unanticipated market or macroeconomic events and circumstances may occur, which could affect the accuracy or validity of the estimates and assumptions used to calculate the fair values of acquired intangible assets.  Preliminary identifiable intangible assets are presented in the following table :  Preliminary Fair Value Weighted Average Useful Lives (in years) Preliminary fair value of intangible assets acquired: Customer relationships $ 417 10 Trade names and trademarks 228 10 Developed technology 179 12 Software assets 94 5 Land use rights 4 22 Intangible assets acquired $ 922 10 T he Company incurred transaction-related expenses associated with the Combination of $128 million and $211 million for the three and nine months ended September 30, 2024 , respectively ( $17 million for the three and nine months ended September 30, 2023 ) . These costs were associated primarily with legal and other professional services and were recorded in transaction and integration- related expenses associated with the Combination . Following the Combination, Smurfit Kappa funded the prepayment and cancellation of WestRock’s credit agreement with an outstanding amount of $750 million ("Delayed Draw Term Facility"). Waivers from lenders removing change in control provisions had previously been received for this loan facility . The outstanding balance of the facility as of July 5, 2024 was recognized as an assumed liability. The repayment did not form part of Merger Consideration. The repayment of the principal ( $750 million ) has been presented as a financing cash outflow with the payment of accrued interest ( $1 million ) reflected within operating activities, each in the Condensed Consolidated Statement of Cash Flows. 2. Acquisitions - continued Outstanding WestRock Stock Based Compensation Awards In connection with the Combination, outstanding WestRock RSU Awards (other than director RSUs) for current employees were replaced with Smurfit Westrock RSU Awards and a cash award equal to $5.00 per share, both of which will vest over the same requisite service period as the original awards. Director RSUs were fully vested upon the change in control and settled shortly thereafter in July 2024. Outstanding WestRock performance stock units ("PSUs") were converted at the higher of target or the average actual performance of the last three years prior to the Merger and replaced with Smurfit Westrock RSU Awards and a cash award equal to $5.00 per share, both of which will vest over the same requisite service period as the original awards. The outstanding WestRock stock options and their exercise prices were converted using an exchange ratio based on the volume weighted average price of Smurfit Kappa shares for a ten day period prior to the close of the Merger and replaced with Smurfit Westrock stock options with the same terms and conditions as the original awards. Outstanding WestRock stock options for former employees were settled in connection with the acquisition. The Merger Consideration includes $101 million related to WestRock awards that were settled or replaced in connection with the acquisition. Compensation expense of $21 million was recognized immediately post-acquisition and $162 million of compensation expense will be recognized over the remaining service period of up to three years . In addition during the quarter ended September 30, 2024 , $44 million of stock compensation expense was recognized in respect of “dual trigger” awards to certain executives, which accelerated vesting upon (i) a change in control and (ii) involuntary termination or a termination for good reason following a change in control. WestRock Net Sales and Earnings  WestRock contributed net sales of $4,684 million and net loss of $132 million to the consolidated results of Smurfit Westrock for the period from completion of the Merger to September 30, 2024 . Unaudited Pro Forma Combined Financial Information  The following unaudited pro forma combined financial information presents the combined results of operations for the three and nine months ended September 30, 2024 and 2023 , as if the Merger had occurred on January 1, 2023.    Three months ended Nine months ended September 30 September 30 2024 2023 2024 2023 Net sales $ 7,931 $ 7,925 $ 23,381 $ 24,688 Net income (loss) attributable to common stockholders $ 33 $ 324 $ 527 $ (1,486) The unaudited pro f orma combined financial information above is based on the historical financial statements of Smurfit Kappa, WestRock, and Smurfit Westrock, and is not indicative of the results of operations that would have been achieved if the Merger had occurred on January 1, 2023, nor is it indicative of future results. The unaudited pro forma combined financial information has been prepared by applying the accounting policies of Smurfit Westrock and includes, where applicable, adjustments for the following factually supportable items or transactions, directly attributable to the Merger: (i) elimination of intercompany activity; (ii) incremental depreciation expense from the preliminary fair value adjustments to property, plant and equipment; (iii) amortization expense from the preliminary fair value adjustments to acquired intangible assets; (iv) incremental stock-based compensation expense associated with the Merger; (v) interest expense for acquisition financing and the amortization of the fair value adjustment to debt assumed; (vi) removal of pension and other postretirement amortization expense resulting from the fair value adjustment to acquired WestRock pension and other post-employment benefit assets and liabilities; (vii) changes to align accounting policies; and (viii) associated tax-related impacts of adjustments . 2. Acquisitions - continued The unaudited pro forma combined financial information also reflects pro forma adjustments for the following material nonrecurring expenses directly attributable to the Merger, each reflected as of the beginning of the earliest pro-forma comparative period presented: (i) transaction-related costs of both Smurfit Kappa and WestRock ( $450 million ), including retention-related bonuses ; and (ii) amortization of the fair value adjustment to acquired inventories of $227 million . These pro forma adjustments are based on available information as of the date hereof and upon assumptions that the Company believes are reasonable to reflect the impact of the Merger on the Company’s historical financial information on a supplemental pro forma basis. Adjustments do not include costs related to integration activities, cost savings or synergies that have been or may be achieved by the combined business.

Segment Information

Segment Information	9 Months Ended
Segment Information	Sep. 30, 2024
Segment Reporting [Abstract]
Segment Information	3. Segment Information Following the completion of the Combination we reassessed our operating segments due to changes in our organizational structure and how our chief operating decision maker (“CODM”) makes key operating decisions, allocates resources and assesses the performance of our business. The CODM is determined to be the executive management team, comprising the President and Chief Executive Officer Anthony Smurfit and the Executive Vice President and Group Chief Financial Officer Ken Bowles. The CODM is responsible for assessing performance, allocating resources and making strategic decisions. During the three months ended September 30, 2024, we identified three operating segments, which are also our reportable segments: i. Europe, the Middle East and Africa (MEA), and Asia-Pacific (APAC). ii. North America , which includes operations in the U.S., Canada and Mexico. iii. Latin America (“LATAM”), which includes operations in Central America and Caribbean, Argentina, Brazil, Chile, Colombia, Ecuador and Peru. These changes reflect how we manage our business during the third quarter of 2024, following the completion of the Combination. No operating segments have been aggregated for disclosure purposes. Prior period comparatives have been restated to reflect the change in segments. In the identification of the operating and reportable segments, we considered the level of integration of our different businesses as well as our objective to develop long-term customer relationships by providing customers with differentiated packaging solutions that enhance the customer’s prospects of success in their end markets. The Europe, MEA and APAC, North America, and LATAM segments are each highly integrated within the segment and there are many interdependencies within these operations. They each include a system of mills and plants that primarily produce a full line of containerboard that is converted into corrugated containers within each segment, or is sold to third parties. In addition, the Europe, MEA and APAC segment also produces types of paper, such as solid board, sack kraft paper, machine glazed and graphic paper; and other paper-based packaging, such as honeycomb, solid board packaging, folding cartons, inserts and labels; and bag-in-box packaging (located in Europe, Argentina, Canada, Mexico and the U.S.). The North America segment also produces paperboard and specialty grades; other paper-based packaging, such as folding cartons, inserts, labels and displays and also engages in the assembly of displays as well as the distribution of packaging products. The LATAM segment also comprises forestry; types of paper, such as boxboard and sack paper; and paper-based packaging, such as folding cartons, honeycomb and paper sacks. Inter-segment transfers or transactions are entered into under normal commercial terms and conditions that would also be available to unrelated third parties. 3. Segment Information - continued Segment profit is measured based on Adjusted EBITDA, defined as (loss) income before income taxes , unallocated corporate costs , depreciation, depletion and amortization , interest expense, net , pension and other postretirement non-service benefit (expense), net , share-based compensation expense , other expense, net , impairment of goodwill and other assets, amortization of fair value step up on inventory , transaction and integration-related expenses associated with the Combination , restructuring costs, legislative or regulatory fines and reimbursements and l osses at closed facilities . The following tables show selected financial data for our segments: Three months ended Nine months ended September 30, September 30, 2024 2023 2024 2023 Net sales (aggregate) Europe, MEA and APAC $ 2,651 $ 2,191 $ 7,056 $ 7,047 North America 4,649 401 5,499 1,239 LATAM 506 341 1,187 1,000 Total $ 7,806 $ 2,933 $ 13,742 $ 9,286 Less net sales (intersegment): Europe, MEA and APAC $ 5 $ 3 $ 13 $ 9 North America 118 — 119 — LATAM 12 15 40 46 Total $ 135 $ 18 $ 172 $ 55 Net sales (unaffiliated customers): Europe, MEA and APAC $ 2,646 $ 2,188 $ 7,043 $ 7,038 North America 4,531 401 5,380 1,239 LATAM 494 326 1,147 954 Total $ 7,671 $ 2,915 $ 13,570 $ 9,231 Adjusted EBITDA: Europe, MEA and APAC $ 411 $ 411 $ 1,158 $ 1,330 North America 780 66 900 209 LATAM 116 74 257 217 Total $ 1,307 $ 551 $ 2,315 $ 1,756 Unallocated corporate costs (42) (26) (95) (74) Depreciation, depletion and amortization (564) (147) (872) (430) Interest expense, net (167) (39) (225) (109) Pension and other postretirement non-service benefit (expense), net 8 (9) (31) (29) Share-based compensation expense (123) (7) (154) (43) Other expense, net (13) (4) (13) (19) Amortization of fair value step up on inventory (227) — (227) — Transaction and integration-related expenses associated with the Combination (267) (17) (350) (17) Other adjustments (29) — (11) — (Loss) income before income taxes $ (117) $ 302 $ 337 $ 1,035 Oth er adjustm ents for the three months ended September 30, 2024 include restructuring costs of $19 million , losses at closed facilities of $8 million and impairment of other assets of $2 million . Other adjustments for the nine months ended September 30, 2024 include restructuring costs of $19 million , losses at closed facilities of $8 million and impairment of other assets of $2 million partially offset by legislative or regulatory fine reimbursement of $18 million . There were no amounts included in other adjustments for the three and nine months ended September 30, 2023 . 3. Segment Information - continued Nine months ended September 30, 2024 2023 Capital expenditures: Europe, MEA and APAC $ 353 $ 411 North America 373 96 LATAM 154 148 Total per reportable segment $ 880 $ 655 Corporate 17 6 Total capital expenditure $ 897 $ 661 September 30, December 31, 2024 2023 Assets: Europe, MEA and APAC $ 11,408 $ 9,521 North America 29,343 1,607 LATAM 3,438 1,795 Total per reportable segment $ 44,189 $ 12,923 Corporate (1) 840 1,128 Total assets $ 45,029 $ 14,051 (1) Corporate assets are composed primarily of Pension assets, Property, plant and equipment net, Derivative financial instruments, Deferred tax assets, Recoverable or refundable income taxes and Cash and cash equivalents.

Revenue Recognition

Revenue Recognition	9 Months Ended
Revenue Recognition	Sep. 30, 2024
Revenue from Contract with Customer [Abstract]
Revenue Recognition	4. Revenue Recognition Disaggregated Revenue ASC 606 requires that we disaggregate revenue from contracts with customers into categories that depict how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors. The following tables summarize our disaggregated revenue with unaffiliated customers by product type and segment for the three and nine months ended September 30, 2024 and 2023 . Net sales are attributed to segments based on the location of production. Three months ended September 30, 2024 Europe, MEA and APAC North America LATAM Total Revenue by product: Paper $ 402 $ 1,107 $ 42 $ 1,551 Packaging 2,244 3,424 452 6,120 Total $ 2,646 $ 4,531 $ 494 $ 7,671 Three months ended September 30, 2023 Europe, MEA and APAC North America LATAM Total Revenue by product: Paper $ 333 $ 25 $ 14 $ 372 Packaging 1,855 376 312 2,543 Total $ 2,188 $ 401 $ 326 $ 2,915 Nine months ended September 30, 2024 Europe, MEA and APAC North America LATAM Total Revenue by product: Paper $ 1,092 $ 1,165 $ 73 $ 2,330 Packaging 5,951 4,215 1,074 11,240 Total $ 7,043 $ 5,380 $ 1,147 $ 13,570 Nine months ended September 30, 2023 Europe, MEA and APAC North America LATAM Total Revenue by product: Paper $ 1,054 $ 81 $ 38 $ 1,173 Packaging 5,984 1,158 916 8,058 Total $ 7,038 $ 1,239 $ 954 $ 9,231 4. Revenue Recognition - continued Packaging revenue is derived mainly from the sale of corrugated and consumer packaging products. The remainder of packaging revenue is composed of bag-in-box, packaging solutions and other paper-based packaging products. Revenue Contract Balances In connection with the Combination, the Company acquired contract assets and assumed contract liabilities. These contract assets relate to the manufacture of certain products that have no alternative use to us, with right to payment for performance completed to date on these products, including a reasonable profit. Contract assets are reduced when the customer takes title to the goods and assumes the risks and rewards for the goods. Contract liabilities represent obligations to transfer goods or services to a customer for which we have received consideration and are reduced once control of the goods is transferred to the customer. Contract assets and contract liabilities are reported within “ Other current assets ” and “ Other current liabilities ” , respectively, on the Condensed Consolidated Balance Sheets . Contract Assets (Short-Term) Contract Liabilities (Short-Term) Recorded on the Combination $ 220 $ 10 Decrease (17) (4) Ending balance - September 30, 2024 $ 203 $ 6

Transaction and integration-cos

Transaction and integration-costs associated with the Combination	9 Months Ended
	Sep. 30, 2024
Equity Method Investments and Joint Ventures [Abstract]
Transaction and integration-costs associated with the Combination	5. Transaction and integration-related costs associated with the Combination The following table summarizes the transaction and integration costs associated with the Combination: Three months ended Nine months ended September 30, September 30, 2024 2023 2024 2023 Transaction-related costs associated with the Combination $ (128) $ (17) $ (211) $ (17) Integration-related costs associated with the Combination (139) — (139) — Total transaction and integration-related costs associated with the Combination $ (267) $ (17) $ (350) $ (17) Transaction-related costs associated with the Combination Transaction-related costs associated with the Combination comprise of banking and financing related costs as well as legal and other professional services which are directly attributable to the Combination and retention payments that are contractually committed to and associated with the successful completion of the Combination. Integration-related costs associated with the Combination We incur integration costs post-acquisition that reflect work performed to facilitate merger and acquisition integration and primarily consist of professional services and personnel and related expenses, such as work associated with information systems. We consider transaction and integration costs to be corporate costs regardless of the segment or segments involved in the transaction.

Accounts Receivable

Accounts Receivable	9 Months Ended
Accounts Receivable	Sep. 30, 2024
Receivables [Abstract]
Accounts Receivable	6. Accounts Receivable Accounts receivable consists of the following: September 30, December 31, 2024 2023 Gross accounts receivable $ 4,830 $ 1,976 Less: Allowances (217) (170) Accounts receivable $ 4,613 $ 1,806 Allowances include the reserves for allowance for estimated credit impairment losses, returns, cash discounts and non-cash rebates where netting requirements are met.

Inventories

Inventories	9 Months Ended
Inventories	Sep. 30, 2024
Inventory Disclosure [Abstract]
Inventories	7. Inventories Inventories are as follows: September 30, December 31, 2024 2023 Finished goods $ 1,364 $ 514 Work in process 240 52 Raw materials 1,378 348 Consumables and spare parts 603 289 Inventories $ 3,585 $ 1,203

Property, Plant, and Equipment

Property, Plant, and Equipment	9 Months Ended
Property, Plant, and Equipment	Sep. 30, 2024
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	8. Property, Plant and Equipment Property, plant and equipment consists of the following: September 30, December 31, 2024 2023 Land and buildings $ 5,531 $ 2,679 Forestlands 272 78 Plant and equipment 22,684 8,860 Construction in progress 1,465 656 Finance lease right-of-use assets 422 32 Property, plant and equipment at cost 30,374 12,305 Less: Accumulated depreciation, depletion and amortization (7,168) (6,514) Property, plant and equipment, net $ 23,206 $ 5,791 Depreciation expense for the three months ended September 30, 2024 and 2023 , w as $517 million and $134 million , respectively, and for the nine months ended September 30, 2024 and 2023 , was $802 million and $392 million , respectively.

Goodwill

Goodwill	9 Months Ended
Goodwill	Sep. 30, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	9. Goodwill During the third quarter of 2024 , the Company changed its reportable segments as described in “Note 3. Segment Information ”. Concurrent with the change in reportable segments, the Company reassessed it’s reporting units. The prior year amounts for goodwill by reportable segment have been recast by assigning reporting units to new reportable segments based on location of reporting units. The Company concluded the change in reportable segments was not a triggering event for goodwill impairment. There were no charges for goodwill impairment in the nine months ended September 30, 2024 . The changes in the carrying amount of goodwill for the period ended September 30, 2024 are as f ollows : Europe, MEA and APAC North America LATAM Total Balance as of December 31, 2023 Goodwill $ 2,653 $ 264 $ 189 $ 3,106 Accumulated impairment losses (209) — (55) (264) 2,444 264 134 2,842 Acquisitions 171 3,990 207 4,368 Translation adjustment 33 (15) (13) 5 Balance as of September 30, 2024 Goodwill 2,860 4,239 378 7,477 Accumulated impairment losses (212) — (50) (262) $ 2,648 $ 4,239 $ 328 $ 7,215 Of the acquisitions amount in the table above, $4,359 million relates to goodwill recognized from the Merger. Further information is included in “Note 2. Acquisitions ”.

Fair Value Measurement

Fair Value Measurement	9 Months Ended
Fair Value Measurement	Sep. 30, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurement	10. Fair Value Measurement The fair values of the Company's financial assets and financial liabilities listed below reflect the amounts that would be received to sell the assets or paid to transfer the liabilities in an orderly transaction between market participants at the measurement date (exit price). The Company's non-derivative financial instruments primarily include cash and cash equivalents, trade and other receivables, certain other current assets, trade and other payables, certain other current liabilities, short-term debt and non-current debt, all of whose carrying values approximates fair value (with the exception of non-current debt with fixed rates). Fair value disclosures are classified based on the fair value hierarchy. See “Note 1. Description of Business and Summary of Significant Accounting Policies ," for information about the Company's fair value hierarchy. The carrying values, net of deferred debt issuance costs, and estimated fair values of debt with fixed interest rates (classified as Level 2 in the fair value hierarchy) were as follows: September 30, 2024 December 31, 2023 Book Value Fair Value Book Value Fair Value Debt with fixed interest rates $ 11,274 $ 11,414 $ 3,615 $ 3,379 The fair value of the Company's debt with fixed interest rates is based on quoted market prices. With the exception of financial instruments included in the table above, the carrying amounts of all other debt instruments approximate their fair values. The variable nature and repricing dates of the receivables securitization facilities and the revolving credit facility result in a carrying value approximating its fair value. Both the revolving credit facility and the receivables securitization facilities are classified as Level 2 in the fair value hierarchy. 10. Fair Value Measurement - continued Assets a nd Liabilities Measured and Recorded at Fair Value on a Recurring B asis The Company measures and records certain assets and liabilities, including derivative instruments at fair value. The following table summarizes the fair value of these instruments, which are measured at fair value on a recurring basis, by level, within the fair value hierarchy : Level 1 Level 2 September 30, December 31, September 30, December 31, 2024 2023 2024 2023 Assets Other Investments: Listed $ 2 $ 2 $ — $ — Unlisted — — 10 9 Derivatives in cash flow hedging relationships — — 2 5 Derivatives not designated as hedging instruments — — 18 14 Assets measured at fair value $ 2 $ 2 $ 30 $ 28 Liabilities Derivatives in cash flow hedging relationships — — 6 8 Derivatives not designated as hedging instruments — — 1 12 Liabilities measured at fair value $ — $ — $ 7 $ 20 There were no assets or liabilities, which are measured at fair value on a recurring basis, classified as Level 3 in the fair value hierarchy for the periods presented. The fair value of listed financial assets is determined by reference to their bid price at the reporting date. Unlisted financial assets are valued using recognized valuation techniques for the underlying security including discounted cash flows and similar unlisted equity valuation models. The fair value of foreign currency forwards, cross currency swaps and energy hedging contracts is based on their listed market pric e, if available. If a listed market price is not available, then fair value is estimated by discounting the difference between the contractual forward price and the current forward price for the residual maturity of the contract using a risk-free interest rate (based on government bonds). The fair value of natural gas commodity derivatives is estimated based on observable inputs such as commodity future prices. We utilize fixed price natural gas commodity derivatives to mitigate the associated price risk resulting from variability in the NYMEX Henry Hub Index. The notional amount of the Company's natural gas commodity program at September 30, 2024 was 10 million MMBtu . The fair values of the hedges are not material. For derivative financial instruments that are not designated as accounting hedges, the entire change in fair value of the financial instrument is reported immediately in current period earnings. 10. Fair Value Measurement - continued Assets a nd Liabilities Measured and Recorded at Fair Value on a Nonr ecurring Basis In addition to assets and liabilities that are recorded at fair value on a recurring basis, the Company records certain assets and liabilities at fair value on a nonrecurring basis. This includes assets acquired and liabilities assumed as a result of business combinations or non- monetary exchanges, situations where events or changes in circumstances indicate the carrying value may not be recoverable, or when they are deemed to be other than temporarily impaired. These assets include goodwill and other intangible assets, assets and disposal groups held for sale and other non-current assets. The fair values of these assets are determined, when applicable, based on valuation techniques using the best information available, and may include quoted market prices, market comparables, and discounted cash flow projections. These nonrecurring fair value measurements are considered to be Level 3 in the fair value hierarchy. For more details on the measurement of assets acquired and liabilities assumed as part of business combinations during the period, refer to “Note 2. Acquisitions ". Accounts Receivable Monetization Agreements A vailable to the Company is a $700 million accounts receivable monetization facility to sell to a third-party financial institution all of the short-term trade receivables generated from certain customer trade accounts. On September 13, 2024 , we amended this agreement to extend the maturity date by one year to September 15, 2025 . This facility (the “Monetization Agreement”) has Coöperatieve Rabobank U.A., New York Branch, as purchaser, (“Rabobank”). The terms of the Monetization Agreements limit the balance of receivables sold to the amount available to fund such receivables sold, thereby eliminating the receivable for proceeds from the financial institution at any transfer date. Transfers under the Monetization Agreement meet the requirements to be accounted for as sales in accordance with guidance in ASC 860, “Transfers and Servicing”. We pay a monthly yield on investment to Rabobank at a rate equal to adjusted Term SOFR plus a margin on the outstanding amount of Rabobank’s investment. The Company has a similar $110 million bilateral facility with Sumitomo Mitsui Banking Corporation, New York Branch as purchaser, with a maturity of December 4, 2024. The customers from these facilities are not included in the r eceivables securitization facilities, as discussed in more detail in “Note 11. Debt ” and "Note 18 . Variable Interest Entities ". 10. Fair Value Measurement - continued The following table presents a summary of these accounts receivable monetization agreements for the nine months ended September 30, 2024 : Receivable from financial institutions recognized as part of Combination $ — Receivables sold to the financial institutions and derecognized (670) Receivables collected by financial institutions 621 Cash proceeds from financial institutions 49 Receivable from financial institutions at September 30, 2024 $ — Receivables sold under these accounts receivable monetization agreements as of the balance sheet date were approximately $711 million . Cash proceeds or payments related to the receivables sold are included in Net cash provided by operating activities in the Condensed Consolidated Statement of Cash Flows in the A ccounts receivable line item. The expense related to the sale of receivables was $12 million for the post-Combination period. The expense recorded may vary depending on current rates and levels of receivables sold and is recorded in “ Other expense, net ” in the Condensed Consolidated Statements of Operations. Although the sales are made without recourse, we maintain continuing involvement with the receivables sold as we provide collections services related to the transferred assets. The associated servicing liability is not material given the high credit quality of the customers underlying the receivables and the anticipated short collection period.

Debt

Debt	9 Months Ended
Debt	Sep. 30, 2024
Debt Disclosure [Abstract]
Debt	11. Debt The following were individual components of debt, split between items previously held by the Company and those assumed as a result of the Combination: September 30, December 31, 2024 2023 Amounts held by Smurfit Kappa prior to the Combination: Revolving credit facility due 2026 $ — $ 4 €100 million receivables securitization variable funding notes due 2026 112 6 €230 million receivables securitization variable funding notes due 2026 223 14 $292.3 million senior debentures due 2025 292 294 €250 million senior notes due 2025 — 279 €1,000 million senior notes due 2026 1,117 1,121 €750 million senior notes due 2027 837 832 €500 million senior green notes due 2029 557 553 $750 million senior green notes due 2030 749 — €500 million senior green notes due 2033 557 553 $1,000 million senior green notes due 2034 1,000 — $1,000 million senior green notes due 2054 1,000 — Bank loans 110 68 Finance lease obligations 27 29 Bank overdrafts 8 16 Amounts assumed in connection with the Combination: $750 million senior notes due 2026 742 — $500 million senior notes due 2027 477 — $600 million senior notes due 2028 578 — $500 million senior notes due 2028 480 — $750 million senior notes due 2029 749 — $400 million senior notes due 2030 456 — $300 million senior notes due 2031 341 — $500 million senior notes due 2032 472 — $76 million senior notes due 2032 82 — $600 million senior notes due 2033 512 — $3 million senior notes due 2037 3 — $150 million senior notes due 2047 175 — $700 million receivables securitization due 2027 525 — Term loan facilities 600 — Commercial paper 512 — Other debt 42 — Vendor financing and commercial card programs 114 — Finance lease obligations 515 — Total debt, excluding debt issuance costs $ 13,964 $ 3,769 Debt issuance costs (45) (22) Total debt 13,919 3,747 Less: Current portion of debt (745) (78) Non-current debt due after one year $ 13,174 $ 3,669 11. Debt - continued For the terms attached to the senior notes (other than those senior notes issued during the three months period ended June 30, 2024) and the receivables securitization facilities, refer to the narrative included in “Note 10. Debt ” of the 2023 Consolidated Financial Statements. The carrying amount of the borrowings designated as Net Investment Hedges, as outlined therein, has not changed materially and no ineffectiveness was recognized in the period. The carrying amount of our debt includes a fair value adjustment related to debt assumed through mergers and acquisitions. At September 30, 2024 the unamortized fair value market adjustment was $58 million , which will be amortized over a weighted average remaining life of 7.4 years . At September 30, 2024 , all of our debt was unsecured with the exception of our r eceivables securitization facilities and finance lease obligations. On August 12 , 2024, we redeemed €250 million a ggregate principal amount of our senior notes due February 2025. We funded this redemption by drawing on our receivables securitization facilities. No gain/loss on extinguishment of debt has been recorded. On September 17, 2024, we discharged $600 million aggregate principal amount of our 3.75% senior notes due March 2025. We funded this discharge using a portion of the proceeds from our Notes Offering which is described in further detail in “Note 2. Acquisitions ”. We recorded a $4 million loss on extinguishment of debt. Senior Notes Issued On April 3, 2024, Smurfit Kappa Treasury completed the Notes Offering. The Company ( a ) used a portion of the proceeds from the Notes Offering (i) to finance the payment of the C ash Consideration of the Combination; (ii) to finance the payment of fees, commissions, costs and expenses in relation to the Combination and the Notes Offering; and (iii) for general corporate purposes, including the repayment of indebtedness, and (b) intends to use an amount equivalent to the proceeds from the Notes Offering to finance or refinance a portfolio of eligible green projects in accordance with Smurfit Kappa’s Green Finance Framework, which the Company may, in the future, update in line with developments in the market. Revolving Credit Facility On June 28, 2024, conditional upon the closing of the Combination, the Company entered into a Multicurrency Term and Revolving Facilities Agreement (the "New Credit Agreement") with certain lenders and Wells Fargo Bank, National Association, as agent, providing for (i) a U.S. dollar term loan facility in an aggregate principal amount of $600 million (the “Term Loan Facility”), (ii) a multicurrency revolving loan facility in an aggregate principal amount of $4,500 million including a swingline sub-facility in an aggregate principal amount of $500 million (together, the “New RCF”). On July 2, 2024, the Term Loan Facility of $600 million under the New Credit Agreement was cancelled prior to any drawdown and no early termination penalties were incurred as a result of the cancellation. We cancelled the €1,350 million Revolving Credit Facility (that was due to mature in January 2026) (the “Existing RCF”) as part of the conditions of the New Credit Agreement upon the closing of the Combination on the Closing Date. There were no early termination penalties incurred as a result of the termination of the Existing RCF. The conditions attaching to the New Credit Agreement becoming effective were completed on the Closing Date. 11. Debt - continued Revolving Credit Facility - continued Loans under the New RCF may be drawn in U.S. dollars, euro, pounds sterling, Swiss francs, Japanese yen, Swedish kronor and Canadian dollars, with a borrower (or the obligors’ agent on behalf of a borrower) selecting the currency of a loan under the New RCF. Borrowings under the New RCF bear interest at rates based upon an underlying reference rate, plus a margin determined in accordance with a ratings-based pricing grid. Reference rates include SOFR for U.S. dollars, EURIBOR for euro, SONIA for pounds sterling, STIBOR for Swedish kronor and SARON for Swiss f ranc s. U nused revolving commitments under the New RCF will accrue a commitment fee equal to a percentage of the applicable interest rate margin. The New RCF also requires the payment of a utilization fee calculated on outstanding revolving loans, based on the utilization rate of the New RCF. The New RCF has an initial term of five years from the date of the New Credit Agreement, which may be extended on two occasions by up to an aggregate of two years. The New RCF is unsecured. A s of September 30, 2024, there were no amounts outstanding under the facility. Term Loan Facilities Farm Loan Credit Facility A credit agreement (the “Farm Credit Facility Agreement”) is in place with CoBank, ACB, as administrative agent. The Farm Credit Facility Agreement provides for a senior unsecured term loan facility in an aggregate principal amount of $600 million (the “Farm Credit Facility”) with a maturity date of July 9, 2029. The carrying value of this facility at September 30, 2024 was $600 million . At our option, loans issued under the Farm Credit Facility will bear interest at either Term SOFR or an alternate base rate, in each case plus an applicable interest rate margin that will fluctuate between 1.650% per annum and 2.275% per annum (for Term SOFR loans) or between 0.650% per annum and 1.275% per annum (for alternate base rate loans), based upon the Company’s corporate credit ratings (as defined in the Farm Credit Facility Agreement). In addition, Term SOFR loans will be subject to a credit spread adjustment equal to 0.1% per annum. Delayed Draw Term Facility A credit agreement with an outstanding amount of $750 million (the “Delayed Draw Term Facility”) was in place at the Combination date. This amount (plus accrued interest) was repaid and the facility cancelled on July 5, 2024. Receivables Securitization Facilities As of September 30, 2024 , the gross amount of receivables collateralizing the €100 million 2026 trade receivables securitization programs were €317 million ( December 31, 2023 : €327 million ). As of September 30, 2024 maximum available borrowings, excluding amounts outstanding under this facility, were $— million ( December 31, 2023 : $105 million ). The gross amount of receivables collateralizing the €230 million 2026 trade receivables securitization program at September 30, 2024 was €422 million ( December 31, 2023 : €415 million ). At September 30, 2024 maximum available borrowings, excluding amounts outstanding under this facility, were $34 million ( December 31, 2023 : $240 million ). In accordance with the contractual terms, the counterparty has recourse to the securitized debtors only . Given the short-term nature of the securitized receivables and the variable floating rates, the carrying amount of the securitized receivables and the associated liabilities reported on the Condensed Consolidated Balance Sheets is estimated to approximate fair value. The Company also has a third receivables securitization program with certain lenders and Coöperatieve Rabobank U.A., New York Branch, in its capacity as administrative agent. It has a facility size of $700 million , a margin of 0.9% plus 0.1% credit spread adjustment and matures in June 2027. At September 30, 2024 maximum available borrowings, excluding amounts outstanding under this facility, were $175 million . The gross carrying amount of receivables collateralizing the maximum available borrowings at September 30, 2024 were approximately $1,137 million . We have continuing involvement with the underlying receivables as we provide credit and collection services pursuant to the underl ying agreement . Borrowing availability under this facility is based on the eligible underlying accounts receivable and compliance with certain covenants. The agreement governing the receivables securitization facility contains restrictions, including, among others, on the creation of certain liens on the underlying collateral. Further details are included in the agreement. 11. Debt - continued Commercial Paper The Company also maintains an unsecured commercial paper program with WRKCo Inc. (a wholly owned subsidiary of Smurfit Westrock plc) as the issuer. Under the program, we may issue senior short-term unsecured commercial paper notes in an aggregate principal amount at any time not to exceed $1,000 million with up to 397 -day maturities. The program has no expiration date and can be terminated by either the agent or us with not less than 30 days notice. The $1,000 million commercial paper program is supported by the $4,500 million New RCF with a separate $500 million swingline sublimit which allows for same-day drawing in U.S. Dollar. The amount of commercial paper outstanding does not reduce available capacity under the New RCF. Commercial paper borrowings may vary during the period, largely as a result of fluctuations in funding requirements . Amounts available under the program may be borrowed, repaid and re-borrowed from time to time. At September 30, 2024 , there was $512 million issued . The weighted average interest rate pertaining to this facility was 5.2% as of that date.

Leases

Leases	9 Months Ended
Leases	Sep. 30, 2024
Leases [Abstract]
Leases	12. Leases We lease various real estate, including certain operating facilities, warehouses, office space and land. We also lease material handling equipment, vehicles and certain other equipment. Components of Lease Costs The following table presents certain information related to the lease costs for finance and operating leases: Three months ended Nine months ended September 30, September 30, 2024 2023 2024 2023 Operating lease costs $ (95) $ (31) $ (168) $ (87) Variable and short-term lease costs (53) (10) (72) (35) Finance lease cost: Amortization of lease assets (23) (1) (25) (2) Interest on lease liabilities (11) — (12) (1) Lease cost $ (182) $ (42) $ (277) $ (125) 12. Leases - continued Supplemental Condensed Consolidated Balance Sheets Information Related to Leases Balance Sheet Location September 30, December 31, 2024 2023 Operating leases: Operating lease right-of-use assets Other non-current assets $ 985 $ 374 Current operating lease liabilities Other current liabilities $ 306 $ 113 Non-current operating lease liabilities Other non-current liabilities 706 269 Total operating lease liabilities $ 1,012 $ 382 Finance leases: Property, Plant and Equipment Property, plant and equipment, net $ 422 $ 32 Accumulated depreciation (25) (6) Property, Plant and Equipment, net $ 397 $ 26 Current finance lease liabilities Current portion of debt $ 32 $ 3 Non-current finance lease liabilities Non-current debt due after one year 510 26 Total finance lease liabilities $ 542 $ 29 Operating lease right-of-use assets and lease liabilities increased by $659 million and $662 million , respectively, as a result of leased assets acquired and liabilities assumed from the Combination. Similarly, finance lease right-of-use assets and lease liabilities have increased by $388 million and $512 million , respectively. Supplemental Cash Flow Information Related to Leases Nine months ended, September 30, 2024 2023 Leased assets obtained in exchange for lease liabilities: Operating leases $ 125 $ 68 Finance leases $ 2 $ —
Leases	12. Leases We lease various real estate, including certain operating facilities, warehouses, office space and land. We also lease material handling equipment, vehicles and certain other equipment. Components of Lease Costs The following table presents certain information related to the lease costs for finance and operating leases: Three months ended Nine months ended September 30, September 30, 2024 2023 2024 2023 Operating lease costs $ (95) $ (31) $ (168) $ (87) Variable and short-term lease costs (53) (10) (72) (35) Finance lease cost: Amortization of lease assets (23) (1) (25) (2) Interest on lease liabilities (11) — (12) (1) Lease cost $ (182) $ (42) $ (277) $ (125) 12. Leases - continued Supplemental Condensed Consolidated Balance Sheets Information Related to Leases Balance Sheet Location September 30, December 31, 2024 2023 Operating leases: Operating lease right-of-use assets Other non-current assets $ 985 $ 374 Current operating lease liabilities Other current liabilities $ 306 $ 113 Non-current operating lease liabilities Other non-current liabilities 706 269 Total operating lease liabilities $ 1,012 $ 382 Finance leases: Property, Plant and Equipment Property, plant and equipment, net $ 422 $ 32 Accumulated depreciation (25) (6) Property, Plant and Equipment, net $ 397 $ 26 Current finance lease liabilities Current portion of debt $ 32 $ 3 Non-current finance lease liabilities Non-current debt due after one year 510 26 Total finance lease liabilities $ 542 $ 29 Operating lease right-of-use assets and lease liabilities increased by $659 million and $662 million , respectively, as a result of leased assets acquired and liabilities assumed from the Combination. Similarly, finance lease right-of-use assets and lease liabilities have increased by $388 million and $512 million , respectively. Supplemental Cash Flow Information Related to Leases Nine months ended, September 30, 2024 2023 Leased assets obtained in exchange for lease liabilities: Operating leases $ 125 $ 68 Finance leases $ 2 $ —

Interest

Interest	9 Months Ended
Interest	Sep. 30, 2024
Interest Income (Expense), Nonoperating [Abstract]
Interest	13. Interest The components of interest expense, net is as follows: Three months ended Nine months ended September 30, September 30, 2024 2023 2024 2023 Interest expense $ (209) $ (46) $ (321) $ (129) Interest income 42 7 96 20 Interest expense, net $ (167) $ (39) $ (225) $ (109) Total cash paid for interest, net of interest received wa s $236 million and $123 million for the nine months ended September 30, 2024 and September 30, 2023 , respectively. Of this, capitalized interest paid was $11 million and $9 million for the nine months ended September 30, 2024 and September 30, 2023 , respectively.

Income Taxes

Income Taxes	9 Months Ended
Income Taxes	Sep. 30, 2024
Income Tax Disclosure [Abstract]
Income Taxes	14. Income Taxes The effective tax rates in the three and nine months ended September 30, 2024 and for the comparative periods ended September 30, 2023 were generally impacted by a combination of factors including the reduction in earnings and the geographical mix of where those earnings were generated, as well as the impacts resulting from the Combination on July 5, 2024. The negative effect from non- deductible expenses was partially offset by the positive effect of earnings that were not subject to tax. The effective tax rate for the nine months ended September 30, 2024 was 48.7% compared to 24.9% for the same period in 2023 . In 2024 , the non-deductible transaction related expenses associated with the Combination contributed to the increase in the rate. This was offset in part by the recognition of non-taxable income, a reduction in the deferred tax liability on unremitted earnings, and other non- recurring items. The effective tax rate for the three months ended September 30, 2024 was (28.2)% compared to 24.2% for the same period in 2023 . In 2024 , this includes the impact of the increase in the non-deductible expenses related to the Combination. During the nine months ended September 30, 2024 and September 30, 2023 , cash paid for income taxes, net of refunds, was $229 million and $308 million , respectively. As a result of the Combination, approximately $520 million of unrecognized tax benefits were acquired.

Retirement Plans

Retirement Plans	9 Months Ended
Retirement Plans	Sep. 30, 2024
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Retirement Plans	15. Retirement Plans The net periodic benefit (income) cost recognized in the Condensed Consolidated Statements of Operations for the three and nine months ended September 30, 2024 and September 30, 2023 , respectively, is composed of the following: Defined Benefit Pension Plans Three months ended September 30 Nine months ended September 30 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans 2024 2023 2024 2023 2024 2023 2024 2023 Service cost $ 5 $ — $ 9 $ 6 $ 5 $ — $ 22 $ 17 Interest cost 50 1 36 24 53 2 78 69 Expected return on assets (70) (1) (34) (21) (71) (2) (78) (62) Amortization of: Net actuarial loss — — 9 7 — — 29 23 Prior service credit — — (1) (1) — — (1) (1) Settlement loss — — — — — — 19 — Total net periodic benefit (income) cost $ (15) $ — $ 19 $ 15 $ (13) $ — $ 69 $ 46 Other Postretirement Benefit Plans Three months ended September 30 Nine months ended September 30 2024 2023 2024 2023 Service cost $ 1 $ — $ 2 $ 1 Interest cost 2 — 2 — Total net periodic benefit cost $ 3 $ — $ 4 $ 1 Service cost is included within “ Cost of goods sold ” and “ Selling, general and administrative expenses ” whil e all ot her components are r ecorded within “ Pension and other postretirement non-service benefit (expense), net ”. As part of the Company’s pension de-risking strategy, annuities were purchased with an insurance company for the pensioners in our Irish Executive Fund during the quarter ended June 30, 2024. As a result of this transaction, a settlement loss occurred when approximately 70% of the projected benefit obligation was settled. In connection with th e Combination, the Company acquired net pension assets of $234 million ( $4,931 million in obligations and $5,165 million in plan assets). The Company expects to contribute $17 million to t hese plans in fiscal year 2024. 15. Retirement Plans - continued As a result of the acquisition of WestRock, we participate in several multiemployer pension plans (“MEPP” or “MEPPs”) that provide retirement benefits to certain union employees in accordance with various collective bargaining agreements and WestRock has participated in other MEPPs in the past. The multiemployer plan expense was immaterial for the three and nine months ended September 30, 2024 . In the normal course of business, we evaluate our potential exposure to MEPPs, including potential withdrawal liabilities. In fiscal 2018, WestRock submitted formal notification to withdraw from the Pace Industry Union-Management Pension Fund (“PIUMPF”) and recorded a liability associated with the withdrawal. Subsequently, in fiscal 2019 and 2020, Westrock received demand letters from PIUMPF, including a demand for withdrawal liabilities and for its proportionate share of PIUMPF's accumulated funding deficiency, and Westrock refined its liability, the impact of which was not significant. WestRock began making monthly payments for the PIUMPF withdrawal liabilities in fiscal 2020, excluding the accumulated funding deficiency demands. We dispute the accumulated funding deficiency demands. In February 2020, WestRock received a demand letter from PIUMPF asserting that it owed $51 million for its pro-rata share of PIUMPF’s accumulated funding deficiency, including interest. Similarly, in April 2020, WestRock received an updated demand letter related to one of its subsidiaries asserting that it owed $1 million of additional accumulated funding deficiency, including interest. In July 2021, PIUMPF filed suit against Westrock in the U.S. District Court for the Northern District of Georgia claiming the right to recover WestRock’s pro rata share of the pension fund’s accumulated funding deficiency along with interest, liquidated damages and attorney's fees. The federal court recently ordered the parties to mediate, and the parties have agreed to mediate on November 21, 2024. We believe we are adequately reserved for this matter. In connection with the Combination, we assumed withdrawal liabilities of $211 million (balance of $212 million at September 30, 2024 ), including liabilities associated with PIUMPF's accumulated funding deficiency demands. With respect to certain other MEPPs, in the event we withdraw from one or more of the MEPPs in the future, it is reasonably possible that we may incur withdrawal liabilities in connection with such withdrawals. Our estimate of any such withdrawal liabilities, both individually and in the aggregate, are not material for the remaining plans in which we participate. Pension Plan Contributions Established funding standards govern the funding requirements for our qualified and approved pensions in various jurisdictions. We fund the benefit payments of our non-qualified or unfunded plans as benefit payments come due. The Company’s contributions for the three and nine months ended September 30, 2024 and September 30, 2023 , respectively, were as follows: Three months ended Nine months ended September 30, September 30, 2024 2023 2024 2023 Defined Benefit Pension Plans Contributions $ 31 $ 24 $ 86 $ 80 Other Postretirement Benefit Plans Contributions $ 2 $ 1 $ 4 $ 2

Earnings Per Share

Earnings Per Share	9 Months Ended
Earnings Per Share	Sep. 30, 2024
Earnings Per Share [Abstract]
Earnings Per Share	16. Earnings Per Share The following table sets forth the computation of basic and diluted earnings per share: Three months ended Nine months ended September 30, September 30, 2024 2023 2024 2023 Numerator: Net (loss) income attributable to common stockholders $ (150) $ 229 $ 173 $ 777 Denominator: Basic weighted average shares outstanding 508 258 342 258 Effect of dilutive share options — 1 2 1 Diluted weighted average shares outstanding 508 259 344 259 Basic (loss) earnings per share attributable to common stockholders $ (0.30) $ 0.89 $ 0.51 $ 3.01 Diluted (loss) earnings per share attributable to common stockholders $ (0.30) $ 0.88 $ 0.50 $ 3.00 The following weighted average share-based compensation awards were not included in computing diluted earnings per share because the effect would have been antidilutive: Three months ended Nine months ended September 30, September 30, 2024 2023 2024 2023 Performance stock units 7 — — — Restricted stock units 3 — — — Total antidilutive shares 10 — — —

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
Commitments and Contingencies	Sep. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	17. Commitments and Contingencies B razil Tax Liability Our subsidiary, WestRock, is challenging claims by the Brazil Federal Revenue Department that we underpaid taxes as a result of amortization of goodwill generated by the 2002 merger of two of its Brazilian subsidiaries. The matter has proceeded through the Brazil Administrative Council of Tax Appeals (“CARF”) principally in two proceedings, covering tax years 2003 to 2008 and 2009 to 2012. The tax, penalty and interest claims relating to both tax periods were administratively finalized and they are now the subject of two annulment actions WestRock has filed in the Brazil federal court. The fraud penalties and interest for tax years 2003 to 2008 remain pending in the court action relating to this period. For tax years 2009 to 2012 the government claim of fraud penalties and interest was resolved and terminated by CARF in favor of WestRock in 2023. We assert that we have no liability in these matters. The total amount in dispute before CARF and in the annulment actions relating to the claimed tax deficiency was R$745 million ( $137 million ) as of September 30, 2024 , including various penalties and interest. The U.S. dollar equivalent has fluctuated significantly due to changes in exchange rates. Resolution of the uncertain tax positions could have a material adverse effect on our cash flows and results of operations or materially benefit our results of operations in future periods depending upon their ultimate resolution. PIUMPF-Related Litigation Refer to “Note 15. Retirement Plans ” for details of legal proceedings filed by PIUMPF against the Company. Asbestos-Related Litigation We have been named as a defendant in asbestos-related personal injury litigation , primarily in relation to the historical operations of certain companies that have been acquired by the Company. To date, the costs resulting from the litigation, including settlement costs, have not been significant. We accrue for the estimated value of pending claims and litigation costs using historical claims information, as well as the estimated value of future claims based on our historical claims experience. As of September 30, 2024 , there were approximately 625 such lawsuits. We believe that we have substantial insurance coverage, subject to applicable deductibles and policy limits, with respect to asbestos claims. We also have valid defenses to these asbestos-related personal injury claims and intend to continue to defend them vigorously. Should the Company’s litigation profile change substantially, or if there are adverse developments in applicable law, it is possible that the Company could incur significantly more costs resolving these cases. We record asbestos-related insurance recoveries that are deemed probable. In assessing the probability of insurance recovery, we make judgments concerning insurance coverage that we believe are reasonable and consistent with our historical dealings and our knowledge of any pertinent solvency issues surrounding the insurers. The Company does not expect the resolution of pending asbestos litigation and proceedings to have a material adverse effect on the Company’s results of operations, financial condition or cash flows. However, it is possible such proceedings or matters could have an adverse effect on the Company's results of operations, financial condition or cash flows. As of September 30, 2024 , the Company had recorded liabilities in respect of these matters of $73 million and estimated insurance recoveries of $46 million . 17. Commitments and Contingencies - continued Italian Competition Authority Investigation In August 2019, the Italian Competition Authority (the “AGCM”) notified approximately 30 companies, of which Smurfit Kappa Italia, a subsidiary of Smurfit Westrock, was one, that an investigation had found the companies to have engaged in anti-competitive practices, in relation to which the AGCM levied a fine of approximately $138 million on Smurfit Kappa Italia, which was paid in 2021. In October 2019, Smurfit Kappa Italia appealed the AGCM’s decision to the First Administrative Court of Appeal (TAR Lazio), however Smurfit Kappa Italia was later notified that this appeal had been unsuccessful. In September 2021, Smurfit Kappa Italia filed a further appeal to the Council of State which published its ruling in February 2023. While some grounds of appeal were dismissed, the Council of State upheld Smurfit Kappa Italia’s arguments regarding the quantification of the fine. As a result, the AGCM was directed to recalculate Smurfit Kappa Italia’s fine. On March 7, 2024, the AGCM notified Smurfit Kappa Italia that its fine had been reduced by approximately $18 million . Smurfit Kappa Italia has appealed the amount of this reduction and a decision on that appeal is expected in 2025. Separate to these proceedings regarding the fine, in May 2023, Smurfit Kappa Italia filed an application with the Council of State for revocation of the February 2023 ruling to the extent that it failed to consider certain pleas that had been raised by Smurfit Kappa Italia on appeal. If successful, the revocation will imply that the Council of State will have to (re-) assess those pleas, which in turn could determine the partial annulment of the August 2019 ACGM decision, although this would not impact the size of the fine levied on Smurfit Kappa Italia. A decision is expected in 2025. After publication of the AGCM’s August 2019 decision, a number of purchasers of corrugated sheets and boxes initiated litigation proceedings against Smurfit Kappa companies, alleging that they were harmed by the alleged anti-competitive practices and seeking damages. These actions are still in early stages and Smurfit Westrock cannot predict its potential liability or their outcomes with certainty at this point in time. In addition, other parties have threatened litigation against Smurfit Westrock seeking damages (either specified or unspecified). It cannot be anticipated whether these threatened actions will become actual litigation proceedings, nor whether any amounts claimed will be the same as those that have been threatened. International Arbitration Against Venezuela Smurfit Kappa, which is now a subsidiary of Smurfit Westrock, announced in 2018 that due to the Government of Venezuela’s measures, Smurfit Kappa no longer exercised control over the business of Smurfit Kappa Carton de Venezuela. Smurfit Kappa’s Venezuelan operations were therefore deconsolidated in the third quarter of 2018. Later that year, Smurfit Kappa’s wholly owned subsidiary, Smurfit Holdings BV, filed an international arbitration claim against the Bolivarian Republic of Venezuela before the World Bank’s International Centre for Settlement of Investment Disputes seeking compensation for Venezuela’s unlawful seizure of its Venezuelan business as well as for other arbitrary, inconsistent and disproportionate State measures that destroyed the value of its investments in Venezuela. Following the exchange of written submissions, an oral hearing was held in September 2022 in Paris. On 28 August 2024, upon the completion of its deliberations, the arbitral tribunal issued an award granting Smurfit Holdings BV, then a wholly owned subsidiary of Smurfit Westrock, compensation in excess of $469 million , plus legal costs of $5 million , plus interest from May 31, 2024 until the date of payment (the “Award”) . In September 2024 Smurfit Holdings BV initiated proceedings against the Bolivarian Republic of Venezuela to enforce the Award. 17. Commitments and Contingencies - continued Combination-Related Litigation In May 2024, in connection with the Combination, two lawsuits were filed by purported stockholders of WestRock challenging the sufficiency of the disclosures that have been made in connection therewith in the definitive proxy statement that WestRock filed with the SEC on April 26, 2024: Robert Scott v. WestRock Company et al., No. 652627/2024 (N.Y.S.), filed on May 21, 2024, and Richard McDaniel v. WestRock Company et al., No. 652638/2024 (N.Y.S.), filed on May 22, 2024. Both complaints, which name WestRock and its directors as defendants, allege state law claims for breach of fiduciary duty. Due to the early stage of this proceeding, the Company cannot predict the outcomes of these matters and cannot reasonably estimate the potential range of loss, if any. Other Litigation We are a defendant in a number of other lawsuits and claims arising out of the conduct of our business. While the ultimate results of such suits or other proceedings against us cannot be predicted, we believe the resolution of these other matters will not have a material adverse effect on our results of operations, financial condition or cash flows .

Variable Interest Entities

Variable Interest Entities	9 Months Ended
Variable Interest Entities	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entities	18. Variable Interest Entities Trade Receivables Securitization Arrangements The Company is a party to arrangements involving securitization of its trade receivables. The arrangements required the establishment of certain special purpose entities namely Smurfit Kappa International Receivables DAC, Smurfit Kappa Receivables plc and Smurfit Kappa European Packaging DAC (a subsidiary of Smurfit Kappa Receivables plc). The sole purpose of the securitization entities is the raising of finance for the Company using the receivables generated by certain operating entities, as collateral. All entities are considered to be variable interest entities. The Company is the primary beneficiary of Smurfit Kappa International Receivables DAC, Smurfit Kappa European Packaging DAC and Smurfit Kappa Receivables plc, through various financing arrangements and due to the fact that it is responsible for the entities’ most significant economic activities. The carrying value of the restricted asset and limited recourse liability as of September 30, 2024 ( $821 million and $336 million respectively) approximates fair value due to the short-term nature of the securitized assets and the floating rates of the liabilities. Timber Note Receivable Securitization Arrangement The Company is also a party to an arrangement involving securitization of its note receivable. Pursuant to the sale of forestlands in 2007, a special purpose entity (“SPE”) namely MeadWestvaco Timber Notes Holding, LLC (“ MWV TN”) received an installment note receivable (“ Timber Note ”). Using this installment note as collateral, the SPE received proceeds under secured financing agreements, which is recorded as a non-recourse liability. Using the Timber Note as collateral, MWV TN received $338 million in proceeds under a secured financing agreement with a bank. Under the terms of the agreement, the liability from this transaction is non-recourse to the Company and is payable from the Timber Note proceeds upon its maturity in October 2027. As a result, the Timber Note is not available to satisfy any obligations of the Company. MWV TN can elect to prepay at any time the liability in whole or in part, however, given that the Timber Note is not prepayable, MWV TN expects to repay the liability at maturity from the Timber Note proceeds. The Company is the primary beneficiary of MWV TN through various financing arrangements and due to the fact that it is responsible for the entity’s most significant economic activities. This entity is considered to be a variable interest entity. The carrying value of the restricted asset and non-recourse liability as of September 30, 2024 approximates fair value due to their floating rates. 18. Variable Interest Entities - continued Green Power Solutions Green Power Solutions of Georgia, LLC ("GPS") is a joint venture providing steam to the Company and electricity to a third party client. The Company owns a 48% interest in GPS and the majority of the debt issued through the entity SP Fiber Holdings Inc. ("SP Fiber"), a 100% owned subsidiary. Based on the commercial and financial relationships in force between SP Fiber and GPS, it has been determined that the SP Fiber has a controlling financial interest in and is the primary beneficiary of GPS. The vehicle holds unrestricted cash of $2 million as of September 30, 2024 . The fair values of the restricted assets and non-recourse liabilities are classified as level 2 within the fair value hierarchy. The carrying amounts of the restricted assets and limited or non-recourse liabilities of Variable Interest Entitie s reported within the Condensed Consolidated Balance Sheets are set out in the following table: September 30, December 31, 2024 2023 Assets Current assets: Cash and cash equivalents, including restricted cash $ 3 $ 3 Accounts receivable 823 816 Non-current assets: Property, plant and equipment, net 41 — Other non-current assets 390 — Total assets $ 1,257 $ 819 Liabilities Current liabilities: Accounts payable $ 7 $ — Current portion of debt 2 — Other current liabilities 2 — Non-current liabilities: Non-current debt due after one year 337 20 Other non-current liabilities 334 — Total liabilities $ 682 $ 20

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	9 Months Ended
Accumulated Other Comprehensive Loss	Sep. 30, 2024
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Loss	19. Accumulated Other Comprehensive Loss The tables below summarize the changes in accumulated other comprehensive loss by component for the three months ended September 30, 2024 : Foreign Currency Translation Cash Flow Hedges Defined Benefit Pension and Postretirement Plans Other Reserves (2) Total (1) Balance at June 30, 2024 $ 1,056 $ 13 $ 753 $ (751) $ 1,071 Other comprehensive (income) loss (86) — 26 — (60) Balance at September 30, 2024 $ 970 $ 13 $ 779 $ (751) $ 1,011 The tables below summarize the changes in accumulated other comprehensive loss by component for the three months ended September 30, 2023 : Foreign Currency Translation Cash Flow Hedges Defined Benefit Pension and Postretirement Plans Other Reserves (2) Total (1) Balance at June 30, 2023 $ 941 $ 25 $ 754 $ (751) $ 969 Other comprehensive loss (income) 139 (7) (25) — 107 Balance at September 30, 2023 $ 1,080 $ 18 $ 729 $ (751) $ 1,076 The tables below summarize the changes in accumulated other comprehensive loss by component for the nine months ended September 30, 2024 : Foreign Currency Translation Cash Flow Hedges Defined Benefit Pension and Postretirement Plans Other Reserves (2) Total (1) Balance at December 31, 2023 $ 789 $ 16 $ 793 $ (751) $ 847 Other comprehensive loss (income) 181 (3) (14) — 164 Balance at September 30, 2024 $ 970 $ 13 $ 779 $ (751) $ 1,011 The tables below summarize the changes in accumulated other comprehensive loss by component for the nine months ended September 30, 2023 : Foreign Currency Translation Cash Flow Hedges Defined Benefit Pension and Postretirement Plans Other Reserves (2) Total (1) Balance at December 31, 2022 $ 1,199 $ 21 $ 740 $ (751) $ 1,209 Other comprehensive income (119) (3) (11) — (133) Balance at September 30, 2023 $ 1,080 $ 18 $ 729 $ (751) $ 1,076 (1) All amounts are net of tax and noncontrolling interest. (2) This relates to a reverse acquisition reserve which arose on the creation of a new parent of the Company prior to the United Kingdom and Ireland listings. 19. Accumulated Other Comprehensive Loss - continued A summary of the components of other comprehensi ve income (loss) , including noncontrolling interest, for the three months ended September 30, 2024 and September 30, 2023 , is as follows: Three months ended Three months ended September 30, 2024 September 30, 2023 Pre-Tax Tax Net of Tax Pre-Tax Tax Net of Tax Foreign currency translation gain (loss) $ 86 $ — $ 86 $ (139) $ — $ (139) Defined benefit pension and other postretirement benefit plans adjustments: Amortization and settlement recognition of net actuarial loss 9 (1) 8 7 (2) 5 Amortization of prior service credit (1) — (1) (1) — (1) Foreign currency (loss) gain - pensions (33) — (33) 21 — 21 Derivatives: Deferred gain recognized on cash flow hedges — — — 7 — 7 Other comprehensive income (loss) 61 (1) 60 (105) (2) (107) Less: Other comprehensive income (loss) attributable to noncontrolling interests — — — — — — Other comprehensive income (loss) attributable to common stockholders $ 61 $ (1) $ 60 $ (105) $ (2) $ (107) A summary of the components of other comprehensive (loss) income, including noncontrolling interest, for the nine months ended September 30, 2024 and September 30, 2023 , is as follows: Nine months ended Nine months ended September 30, 2024 September 30, 2023 Pre-Tax Tax Net of Tax Pre-Tax Tax Net of Tax Foreign currency translation (loss) gain $ (181) $ — $ (181) $ 119 $ — $ 119 Defined benefit pension and other postretirement benefit plans adjustments: Net actuarial loss arising during period (1) — (1) — — — Amortization and settlement recognition of net actuarial loss 48 (12) 36 23 (6) 17 Amortization of prior service credit (1) — (1) (1) — (1) Foreign currency loss - pensions (20) — (20) (5) — (5) Derivatives: Deferred gain recognized on cash flow hedges 3 — 3 3 — 3 Other comprehensive (loss) income (152) (12) (164) 139 (6) 133 Less: Other comprehensive (loss) income attributable to noncontrolling interests — — — — — — Other comprehensive (loss) income attributable to common stockholders $ (152) $ (12) $ (164) $ 139 $ (6) $ 133

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Millions	3 Months Ended		9 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Millions	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Pay vs Performance Disclosure
Net (loss) income	$ (150)	$ 229	$ 173	$ 777

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Sep. 30, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Description of Business and S_2

Description of Business and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Basis of Presentation	1.2. Basis of Presentation Other than activities related to its formation and in anticipation of the Combination, Smurfit Westrock did not conduct any operations from its incorporation until completion of the Combination. Given the non-operational nature of Smurfit Westrock prior to the Combination, the Smurfit Kappa Share Exchange is not considered a business combination and does not give rise to any goodwill or adjustments to accounting basis. The c onsolidated financial statements of Smurfit Westrock following the Smurfit Kappa Share Exchange are a continuation of the financial statements of Smurfit Kappa. The comparative financial information presented in these Condensed Consolidated Financial Statements reflect the pre-Combination carrying values of Smurfit Kappa with the legal share capital retroactively adjusted to reflect the legal capital of Smurfit Westrock as the successor after giving effect to the Smurfit Kappa Share Exchange. The Merger is recognized as a business combination under Accounting Standards Codification (“ASC”) 805, “Business Combinations” (“ASC 805”). Smurfit Kappa was determined to be the accounting acquirer of WestRock . Accordingly, the financial statements reflected in these Condensed Consolidated Financial Statements include WestRock's financial position and results of operations for the period subsequent to the completion of the Combination on July 5, 2024. Refer to “Note 2. Acquisitions ” for additional information related to the accounting for the Combination. Following the completion of the Combination, we reassessed our reportable segments due to changes in our organizational structure and how our chief operating decision maker (“CODM”) makes key operating decisions, allocates resources and assesses the performance of our business. Consequently, subsequent to the Combination, we began to manage the combined business as three reportable segments: (1) Europe, the Middle East and Africa (“MEA”), and Asia-Pacific (“APAC”), (2) North America, and (3) Latin America (“LATAM”). 1.2. Basis of Presentation - continued As a result of the change in reportable segments, prior year amounts have been recast to conform to the current year presentation. Throughout this Quarterly Report on Form 10-Q, amounts and activity reflect reclassifications related to the Company's change in reportable segments. The change in reportable segments had no impact on the Company’s Condensed Consolidated Balance Sheets, Condensed Consolidated Statements of Operations , Condensed Consolidated Statements of Comprehensive (Loss) Income , Condensed Consolidated Statements of Cash Flows and Condensed Consolidated Statements of Changes in Equity previously reported. Refer to “Note 3. Segment Information ”, for further discussion of the Company’s segment reporting structure. We derived the Condensed Consolidated Balance Sheet as of December 31, 2023 from the audited Consolidated Financial Statements of Smurfit Kappa for the year ended December 31, 2023 (the “2023 Consolidated Financial Statements”) included in the Proxy Statement/Prospectus of Smurfit Westrock dated April 26, 2024 (file number 333-278185). In the opinion of Smurfit Westrock’s management , all normal recurring adjustments necessary for the fair statement of the Consolidated Financial Statements have been included for the interim periods reported. The interim financial statements have been prepared in accordance with accounting principles generally accepted in the U.S. (“GAAP”) for interim financial information and with Article 10 of Regulation S-X of the Securities and Exchange Commission (“SEC”). Accordingly, they omit certain notes and other information from the 2023 Consolidated Financial Statements. Therefore, these interim financial statements should be read in conjunction with the 2023 Consolidated Financial Statements. The results for the three and nine months ended September 30, 2024 are not necessarily indicative of results that may be expected for the full year. The preparation of the Condensed Consolidated Financial Statements requires management to make certain estimates and assumptions about future events. These estimates and the underlying assumptions affect the amounts of assets and liabilities reported, disclosures about contingent assets and liabilities and reported amounts of revenues and expenses. Such estimates include fair value of acquired assets and assumed liabilities, goodwill impairment, income taxes and pension and other postretirement benefits. These estimates and assumptions are based on management’s judgment. Actual results may differ from those estimates, and the differences could be material. Estimates and underlying assumptions are reviewed on an ongoing basis. Changes in accounting estimates may be necessary if there are changes in the circumstances or experiences on which the estimate was based or as a result of new information. Changes in estimates, including those resulting from changes in the economic environment, are reflected in the period in which the change in estimate occurs. Due to rounding, numbers presented throughout this document may not add up precisely to the totals provided and percentages may not precisely reflect the absolute figures. Following the Combination, certain reclassifications have been made to the prior year amounts to conform to the current year presentation. These reclassifications include reclassifications within our segments, as described above. On completion of the Merger, as part of the harmonization of accounting policies, a disclosure reclassification of amounts previously classified as 'other postretirement benefit plans' took place with the plans now being classified and disclosed as 'defined benefit pension plans'. The prior year disclosure information in “Note 15. Retirement Plans ” has been updated to conform to the current year presentation.
Revenue Recognition	1.4. Revenue Recognition The Company's revenue is primarily derived from the sale of containerboard, corrugated containers and other paper-based packaging products. All revenue relates to revenue from contracts with customers. Contracts with customers include a single performance obligation to sell these products and do not generally contain multiple performance obligations. We recognize revenue on a point-in-time basis when the customer takes title to the goods and assumes the risks and rewards for the goods, which coincides with the transfer of control of our goods to the customer upon delivery. Additionally, we manufacture certain customized products that have no alternative use to us (since they are made to specific customer specifications), and we believe that for certain customers we have a legally enforceable right to payment for performance completed to date on these products, including a reasonable profit. For products that meet these two criteria, we recognize revenue over time . This results in revenue recognition prior to the date of shipment or title transfer for these products and results in the recognition of a contract asset (unbilled receivables) with a corresponding reduction in finished goods inventory on our Condensed Consolidated Balance Sheets . Revenue is measured as the amount of consideration we expect to receive in exchange for transferring goods and is derived primarily from fixed consideration. Certain contracts may also include variable consideration, typically in the form of volume-based rebates and early settlement discounts. If a contract with a customer includes variable consideration, we estimate the expected impact based on historical experience and net the provisions for volume-based rebates, early settlement discounts and other adjustments against our gross sales. We concluded this method is consistent with the most likely amount method under ASC 606, “Revenue from Contracts with Customers” (“ASC 606”) and allows us to make the best estimate of the consideration we will be entitled to from customers. As permitted by ASC 606, we have elected to treat costs associated with obtaining new contracts as expenses when incurred if the amortization period of the asset we would recognize is one year or less. We do not record interest income when the difference in timing of control transfer and customer payment is one year or less. No element of financing is deemed present as the sales are made with credit terms consistent with market practice and are in line with normal credit terms in the entities’ country of operation. We also account for sales and other taxes that are imposed on and concurrent with individual revenue-producing transactions between a customer and us on a net basis which excludes the taxes from our net sales .
Fair Value of Financial Instruments and Nonfinancial Assets and Liabilities	1.5. Fair Value of Financial Instruments and Nonfinancial Assets and Liabilities We estimate fair values in accordance with ASC 820 “Fair Value Measurement” (“ASC 820”). ASC 820 provides a framework for measuring fair value and expands disclosures required about fair value measurements. Specifically, ASC 820 sets forth a definition of fair value and a hierarchy prioritizing the inputs to valuation techniques. ASC 820 defines fair value as the price that would be received from the sale of an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Additionally, ASC 820 defines levels within the hierarchy based on the availability of quoted prices for identical items in active markets, similar items in active or inactive markets and valuation techniques using observable and unobservable inputs. We incorporate credit valuation adjustments to reflect both our own nonperformance risk and the respective counterparty’s nonperformance risk in our fair value measurements. The hierarchy consists of: • Level 1: fair value measurements represent exchange-traded securities, which are valued at quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access as of the reporting date; • Level 2: fair value measurements are determined using input prices that are directly observable for the asset or liability or indirectly observable through corroboration with observable market data; and • Level 3: fair value measurements are determined using unobservable inputs, such as internally developed pricing models for the asset or liability due to little or no market activity for the asset or liability. 1. Description of Business and Summary of Significant Accounting Policies - continued 1.5. Fair Value of Financial Instruments and Nonfinancial Assets and Liabilities - continued Financial instruments not recognized at fair value on a recurring or nonrecurring basis include cash and cash equivalents, accounts receivable , certain other current assets, short-term debt, accounts payable, certain other current liabilities and non-current debt. With the exception of non-current debt, the carrying amounts of these financial instruments approximate their fair values due to their short maturities. The fair value of debt such as debentures and various notes are based on quoted market prices as of the balance sheet date. The fair value of the revolving credit facility approximates its carrying value due to the nature of the repricing and interest based on variable rates. Following the Combination, w e have financial instruments recognized at fair value including supplemental retirement savings plans (“Supplemental Plans”) that are nonqualified deferred compensation plans pursuant to which assets are invested primarily in mutual funds, interest rate derivatives, commodity derivatives or other similar class of assets or liabilities. Assets and liabilities held in respect of these Supplemental Plans were $181 million and $168 million , respectively, as of September 30, 2024. We measure the fair value of our mutual fund investments based on quoted prices in active markets. Additionally, we measure our derivative contracts, if any, based on observable inputs such as interest rates, yield curves, spot and future commodity prices, and spot and future exchange rates . We discuss fair values in more detail in “Note 10. Fair Value Measurement ”.
Supplier Finance Program Obligations	1.6. Supplier Finance Program Obligations We maintain supplier finance programs whereby we have entered into payment processing agreements with certain financial institutions. These agreements allow participating suppliers to track payment obligations from Smurfit Westrock , and if voluntarily elected by the supplier, to sell payment obligations from Smurfit Westrock to financial institutions at a discounted price. We are not a party to the agreements between the participating financial institutions and the suppliers in connection with the program, and we do not reimburse suppliers for any costs they incur for participation in the program. We have not pledged any assets as security or provided any guarantees as part of the programs. We have no economic interest in our suppliers’ decisions to participate in the programs. Our responsibility is limited to making payment in full to the respective financial institution according to the terms originally negotiated with the supplier, which generally do not exceed 120 days . Smurfit Westrock or the financial institutions may terminate the agreements upon 30 or 90 days’ notice. Following the Combination, we assumed outstanding payment obligations to financial institutions and the outstanding payment obligations under these programs were $432 million as of September 30, 2024 . These obligations are classified as accounts payable within the Condensed Consolidated Balance Sheet s .
New Accounting Standards Not Yet Adopted	1.7. New Accounting Standards Not Yet Adopted In November 2023, the FASB issued ASU 2023-07, “Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures.” This ASU requires an entity to disclose incremental segment information, including enhanced disclosures about significant segment expenses. ASU 2023-07 is effective for the Company’s annual reporting periods beginning after December 15, 2023 and for interim periods beginning after December 15, 2024. Adoption is a fully retrospective method of transition. Early adoption is permitted. The Company is currently evaluating the effect that adoption of ASU 2023-07 will have on its Consolidated Financial Statements. In December 2023, the FASB issued ASU 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures.” This ASU requires the annual financial statements to include consistent categories and greater disaggregation of information in the rate reconciliation, and income taxes paid disaggregated by jurisdiction. ASU 2023-09 is effective for the Company’s annual reporting periods beginning after December 15, 2024. Adoption is either with a prospective method or a fully retrospective method of transition. Early adoption is permitted. The Company is currently evaluating the effect that adoption of ASU 2023-09 will have on its Consolidated Financial Statements.

Acquisitions (Tables)

Acquisitions (Tables)	9 Months Ended
Acquisitions (Tables)	Sep. 30, 2024
Business Combination, Asset Acquisition, and Joint Venture Formation [Abstract]
Schedule of Merger Consideration	The following table summarizes the components of the aggregate M erger Consideration. T he amounts are calculated by reference to Smurfit Kappa’s share price of £36.56 on the Closing Date, translated to U.S. dollars using the closing exchange rate as of that date.  Cash paid for outstanding WestRock Stock (a) $ 1,291 Smurfit Westrock Shares issued to WestRock Stockholders (b) 12,098 Converted WestRock Options and WestRock RSU Awards attributable to pre-Combination service (c) 101 Settlement of pre-existing relationships, trade and other payable and receivable balances with WestRock (d) (29) Aggregate Merger Consideration $ 13,461 (a) The cash component of the aggregate Merger Consideration is ba sed on 258,228,403 shares of WestRock Stock multiplied by the Cash Consideration of $5.00 per WestRock shar e.   (b) Value of Smurfit Westrock Shares issued is based on 258,228,403 shares of outstanding WestRock Stock resulting in the issue of 258,228,403 Smurfit Westrock Shares at the closing share price of £36.56 on July 5, 2024, translated to U.S. dollars using the closing exchan ge rate of £1 to $1.2815 as of that date.  (c) Consideration for WestRock Options and WestRock restricted stock unit (“ RSU”) Awards replaced with Smurfit Westrock equity awards with similar terms, and the amount represents the consideration for their replacement. A portion of the fair value of Smurfit Westrock equity awards issued represents consideration transferred, while the remaining portion represents the post-Combination compensation expense based on the vesting terms of the converted awards. Also included , is the Merger Consideration in respect of WestRock Director RSU Awards, settled options held by former WestRock employees and vested and unreleased RSU awards all of which converted into WestRock Stock immediately prior to the Closing Date. (d) Component of Merger Consideration in respect of the settlement for no gain or loss of trade and other receivable and payable balances with WestRock as of the date of the Merger. The Merger Consideration has been increased by the amount of the settled Smurfit Kappa receivable of $3 million in respect of sales to WestRock and has been reduced to account for the effective settlement of accounts payable of $32 million in respect of trade and other purchases from WestRock. The WestRock receivable and payable in respect of these inter-company transactions were not recognized as an acquired asset or assumed liability.
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The prelimina ry allocation of the purchase price to the assets acquired and liabilities assumed, and a reconciliation to total consideration transferred is presented in the table below : Identifiable net assets: Cash and cash equivalents $ 603 Accounts receivable 2,374 Inventories 2,504 Other current assets 825 Property, plant and equipment 17,567 Intangibles 922 Prepaid pension asset 558 Other non-current assets 1,765 Accounts payable (2,018) Accrued compensation and benefits (447) Current portion of debt (1,285) Other current liabilities (1,123) Non-current debt due after one year (7,438) Deferred tax liabilities (3,523) Pension liabilities and other postretirement benefits, net of current portion (299) Other non-current liabilities (1,872) Noncontrolling interests (11) Identifiable net assets acquired as of July 5, 2024 9,102 Goodwill arising on Merger 4,359 Aggregate Merger Consideration $ 13,461
Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination	Preliminary identifiable intangible assets are presented in the following table :  Preliminary Fair Value Weighted Average Useful Lives (in years) Preliminary fair value of intangible assets acquired: Customer relationships $ 417 10 Trade names and trademarks 228 10 Developed technology 179 12 Software assets 94 5 Land use rights 4 22 Intangible assets acquired $ 922 10
Schedule of Pro Forma Information	The following unaudited pro forma combined financial information presents the combined results of operations for the three and nine months ended September 30, 2024 and 2023 , as if the Merger had occurred on January 1, 2023.    Three months ended Nine months ended September 30 September 30 2024 2023 2024 2023 Net sales $ 7,931 $ 7,925 $ 23,381 $ 24,688 Net income (loss) attributable to common stockholders $ 33 $ 324 $ 527 $ (1,486)

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
Segment Information (Tables)	Sep. 30, 2024
Segment Reporting [Abstract]
Reconciliation of Operating Profit (Loss) from Segments to Consolidated	The following tables show selected financial data for our segments: Three months ended Nine months ended September 30, September 30, 2024 2023 2024 2023 Net sales (aggregate) Europe, MEA and APAC $ 2,651 $ 2,191 $ 7,056 $ 7,047 North America 4,649 401 5,499 1,239 LATAM 506 341 1,187 1,000 Total $ 7,806 $ 2,933 $ 13,742 $ 9,286 Less net sales (intersegment): Europe, MEA and APAC $ 5 $ 3 $ 13 $ 9 North America 118 — 119 — LATAM 12 15 40 46 Total $ 135 $ 18 $ 172 $ 55 Net sales (unaffiliated customers): Europe, MEA and APAC $ 2,646 $ 2,188 $ 7,043 $ 7,038 North America 4,531 401 5,380 1,239 LATAM 494 326 1,147 954 Total $ 7,671 $ 2,915 $ 13,570 $ 9,231 Adjusted EBITDA: Europe, MEA and APAC $ 411 $ 411 $ 1,158 $ 1,330 North America 780 66 900 209 LATAM 116 74 257 217 Total $ 1,307 $ 551 $ 2,315 $ 1,756 Unallocated corporate costs (42) (26) (95) (74) Depreciation, depletion and amortization (564) (147) (872) (430) Interest expense, net (167) (39) (225) (109) Pension and other postretirement non-service benefit (expense), net 8 (9) (31) (29) Share-based compensation expense (123) (7) (154) (43) Other expense, net (13) (4) (13) (19) Amortization of fair value step up on inventory (227) — (227) — Transaction and integration-related expenses associated with the Combination (267) (17) (350) (17) Other adjustments (29) — (11) — (Loss) income before income taxes $ (117) $ 302 $ 337 $ 1,035
Schedule of Segment Reporting Information, by Segment	Nine months ended September 30, 2024 2023 Capital expenditures: Europe, MEA and APAC $ 353 $ 411 North America 373 96 LATAM 154 148 Total per reportable segment $ 880 $ 655 Corporate 17 6 Total capital expenditure $ 897 $ 661 September 30, December 31, 2024 2023 Assets: Europe, MEA and APAC $ 11,408 $ 9,521 North America 29,343 1,607 LATAM 3,438 1,795 Total per reportable segment $ 44,189 $ 12,923 Corporate (1) 840 1,128 Total assets $ 45,029 $ 14,051 (1) Corporate assets are composed primarily of Pension assets, Property, plant and equipment net, Derivative financial instruments, Deferred tax assets, Recoverable or refundable income taxes and Cash and cash equivalents.

Revenue Recognition (Tables)

Revenue Recognition (Tables)	9 Months Ended
Revenue Recognition (Tables)	Sep. 30, 2024
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregated Revenue With Unaffiliated Customers	The following tables summarize our disaggregated revenue with unaffiliated customers by product type and segment for the three and nine months ended September 30, 2024 and 2023 . Net sales are attributed to segments based on the location of production. Three months ended September 30, 2024 Europe, MEA and APAC North America LATAM Total Revenue by product: Paper $ 402 $ 1,107 $ 42 $ 1,551 Packaging 2,244 3,424 452 6,120 Total $ 2,646 $ 4,531 $ 494 $ 7,671 Three months ended September 30, 2023 Europe, MEA and APAC North America LATAM Total Revenue by product: Paper $ 333 $ 25 $ 14 $ 372 Packaging 1,855 376 312 2,543 Total $ 2,188 $ 401 $ 326 $ 2,915 Nine months ended September 30, 2024 Europe, MEA and APAC North America LATAM Total Revenue by product: Paper $ 1,092 $ 1,165 $ 73 $ 2,330 Packaging 5,951 4,215 1,074 11,240 Total $ 7,043 $ 5,380 $ 1,147 $ 13,570 Nine months ended September 30, 2023 Europe, MEA and APAC North America LATAM Total Revenue by product: Paper $ 1,054 $ 81 $ 38 $ 1,173 Packaging 5,984 1,158 916 8,058 Total $ 7,038 $ 1,239 $ 954 $ 9,231
Schedule of Contract Assets and Liabilities	Contract Assets (Short-Term) Contract Liabilities (Short-Term) Recorded on the Combination $ 220 $ 10 Decrease (17) (4) Ending balance - September 30, 2024 $ 203 $ 6

Transaction and integration-c_2

Transaction and integration-costs associated with the Combination (Tables)	9 Months Ended
	Sep. 30, 2024
Equity Method Investments and Joint Ventures [Abstract]
Summary of Transaction and integration costs associated with the Combination	The following table summarizes the transaction and integration costs associated with the Combination: Three months ended Nine months ended September 30, September 30, 2024 2023 2024 2023 Transaction-related costs associated with the Combination $ (128) $ (17) $ (211) $ (17) Integration-related costs associated with the Combination (139) — (139) — Total transaction and integration-related costs associated with the Combination $ (267) $ (17) $ (350) $ (17)

Accounts Receivable (Tables)

Accounts Receivable (Tables)	9 Months Ended
Accounts Receivable (Tables)	Sep. 30, 2024
Receivables [Abstract]
Schedule of Accounts Receivable	September 30, December 31, 2024 2023 Gross accounts receivable $ 4,830 $ 1,976 Less: Allowances (217) (170) Accounts receivable $ 4,613 $ 1,806

Inventories (Tables)

Inventories (Tables)	9 Months Ended
Inventories (Tables)	Sep. 30, 2024
Inventory Disclosure [Abstract]
Schedule of Inventory	September 30, December 31, 2024 2023 Finished goods $ 1,364 $ 514 Work in process 240 52 Raw materials 1,378 348 Consumables and spare parts 603 289 Inventories $ 3,585 $ 1,203

Property, Plant, and Equipment

Property, Plant, and Equipment (Tables)	9 Months Ended
Property, Plant, and Equipment (Tables)	Sep. 30, 2024
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Equipment	Property, plant and equipment consists of the following: September 30, December 31, 2024 2023 Land and buildings $ 5,531 $ 2,679 Forestlands 272 78 Plant and equipment 22,684 8,860 Construction in progress 1,465 656 Finance lease right-of-use assets 422 32 Property, plant and equipment at cost 30,374 12,305 Less: Accumulated depreciation, depletion and amortization (7,168) (6,514) Property, plant and equipment, net $ 23,206 $ 5,791

Goodwill (Tables)

Goodwill (Tables)	9 Months Ended
Goodwill (Tables)	Sep. 30, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The changes in the carrying amount of goodwill for the period ended September 30, 2024 are as f ollows : Europe, MEA and APAC North America LATAM Total Balance as of December 31, 2023 Goodwill $ 2,653 $ 264 $ 189 $ 3,106 Accumulated impairment losses (209) — (55) (264) 2,444 264 134 2,842 Acquisitions 171 3,990 207 4,368 Translation adjustment 33 (15) (13) 5 Balance as of September 30, 2024 Goodwill 2,860 4,239 378 7,477 Accumulated impairment losses (212) — (50) (262) $ 2,648 $ 4,239 $ 328 $ 7,215

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	9 Months Ended
Fair Value Measurement (Tables)	Sep. 30, 2024
Fair Value Disclosures [Abstract]
Fair Value, by Balance Sheet Grouping	The carrying values, net of deferred debt issuance costs, and estimated fair values of debt with fixed interest rates (classified as Level 2 in the fair value hierarchy) were as follows: September 30, 2024 December 31, 2023 Book Value Fair Value Book Value Fair Value Debt with fixed interest rates $ 11,274 $ 11,414 $ 3,615 $ 3,379
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The Company measures and records certain assets and liabilities, including derivative instruments at fair value. The following table summarizes the fair value of these instruments, which are measured at fair value on a recurring basis, by level, within the fair value hierarchy : Level 1 Level 2 September 30, December 31, September 30, December 31, 2024 2023 2024 2023 Assets Other Investments: Listed $ 2 $ 2 $ — $ — Unlisted — — 10 9 Derivatives in cash flow hedging relationships — — 2 5 Derivatives not designated as hedging instruments — — 18 14 Assets measured at fair value $ 2 $ 2 $ 30 $ 28 Liabilities Derivatives in cash flow hedging relationships — — 6 8 Derivatives not designated as hedging instruments — — 1 12 Liabilities measured at fair value $ — $ — $ 7 $ 20
Accounts Receivable Monetization Agreements	The following table presents a summary of these accounts receivable monetization agreements for the nine months ended September 30, 2024 : Receivable from financial institutions recognized as part of Combination $ — Receivables sold to the financial institutions and derecognized (670) Receivables collected by financial institutions 621 Cash proceeds from financial institutions 49 Receivable from financial institutions at September 30, 2024 $ —

Debt (Tables)

Debt (Tables)	9 Months Ended
Debt (Tables)	Sep. 30, 2024
Debt Disclosure [Abstract]
Schedule of Individual Components of Debt	The following were individual components of debt, split between items previously held by the Company and those assumed as a result of the Combination: September 30, December 31, 2024 2023 Amounts held by Smurfit Kappa prior to the Combination: Revolving credit facility due 2026 $ — $ 4 €100 million receivables securitization variable funding notes due 2026 112 6 €230 million receivables securitization variable funding notes due 2026 223 14 $292.3 million senior debentures due 2025 292 294 €250 million senior notes due 2025 — 279 €1,000 million senior notes due 2026 1,117 1,121 €750 million senior notes due 2027 837 832 €500 million senior green notes due 2029 557 553 $750 million senior green notes due 2030 749 — €500 million senior green notes due 2033 557 553 $1,000 million senior green notes due 2034 1,000 — $1,000 million senior green notes due 2054 1,000 — Bank loans 110 68 Finance lease obligations 27 29 Bank overdrafts 8 16 Amounts assumed in connection with the Combination: $750 million senior notes due 2026 742 — $500 million senior notes due 2027 477 — $600 million senior notes due 2028 578 — $500 million senior notes due 2028 480 — $750 million senior notes due 2029 749 — $400 million senior notes due 2030 456 — $300 million senior notes due 2031 341 — $500 million senior notes due 2032 472 — $76 million senior notes due 2032 82 — $600 million senior notes due 2033 512 — $3 million senior notes due 2037 3 — $150 million senior notes due 2047 175 — $700 million receivables securitization due 2027 525 — Term loan facilities 600 — Commercial paper 512 — Other debt 42 — Vendor financing and commercial card programs 114 — Finance lease obligations 515 — Total debt, excluding debt issuance costs $ 13,964 $ 3,769 Debt issuance costs (45) (22) Total debt 13,919 3,747 Less: Current portion of debt (745) (78) Non-current debt due after one year $ 13,174 $ 3,669

Leases (Tables)

Leases (Tables)	9 Months Ended
Leases (Tables)	Sep. 30, 2024
Leases [Abstract]
Schedule of Components of Lease Costs	The following table presents certain information related to the lease costs for finance and operating leases: Three months ended Nine months ended September 30, September 30, 2024 2023 2024 2023 Operating lease costs $ (95) $ (31) $ (168) $ (87) Variable and short-term lease costs (53) (10) (72) (35) Finance lease cost: Amortization of lease assets (23) (1) (25) (2) Interest on lease liabilities (11) — (12) (1) Lease cost $ (182) $ (42) $ (277) $ (125) Nine months ended, September 30, 2024 2023 Leased assets obtained in exchange for lease liabilities: Operating leases $ 125 $ 68 Finance leases $ 2 $ —
Schedule of Supplemental Balance Sheet Information Related to Leases	Balance Sheet Location September 30, December 31, 2024 2023 Operating leases: Operating lease right-of-use assets Other non-current assets $ 985 $ 374 Current operating lease liabilities Other current liabilities $ 306 $ 113 Non-current operating lease liabilities Other non-current liabilities 706 269 Total operating lease liabilities $ 1,012 $ 382 Finance leases: Property, Plant and Equipment Property, plant and equipment, net $ 422 $ 32 Accumulated depreciation (25) (6) Property, Plant and Equipment, net $ 397 $ 26 Current finance lease liabilities Current portion of debt $ 32 $ 3 Non-current finance lease liabilities Non-current debt due after one year 510 26 Total finance lease liabilities $ 542 $ 29

Interest (Tables)

Interest (Tables)	9 Months Ended
Interest (Tables)	Sep. 30, 2024
Interest Income (Expense), Nonoperating [Abstract]
Components of Interest Expense	The components of interest expense, net is as follows: Three months ended Nine months ended September 30, September 30, 2024 2023 2024 2023 Interest expense $ (209) $ (46) $ (321) $ (129) Interest income 42 7 96 20 Interest expense, net $ (167) $ (39) $ (225) $ (109) Total cash paid for interest, net of interest received wa s $236 million and $123 million for the nine months ended September 30, 2024 and September 30, 2023 , respectively. Of this, capitalized interest paid was $11 million and $9 million for the nine months ended September 30, 2024 and September 30, 2023 , respectively.

Retirement Plans (Tables)

Retirement Plans (Tables)	9 Months Ended
Retirement Plans (Tables)	Sep. 30, 2024
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Schedule of Net Benefit Costs	The net periodic benefit (income) cost recognized in the Condensed Consolidated Statements of Operations for the three and nine months ended September 30, 2024 and September 30, 2023 , respectively, is composed of the following: Defined Benefit Pension Plans Three months ended September 30 Nine months ended September 30 U.S. Plans Non-U.S. Plans U.S. Plans Non-U.S. Plans 2024 2023 2024 2023 2024 2023 2024 2023 Service cost $ 5 $ — $ 9 $ 6 $ 5 $ — $ 22 $ 17 Interest cost 50 1 36 24 53 2 78 69 Expected return on assets (70) (1) (34) (21) (71) (2) (78) (62) Amortization of: Net actuarial loss — — 9 7 — — 29 23 Prior service credit — — (1) (1) — — (1) (1) Settlement loss — — — — — — 19 — Total net periodic benefit (income) cost $ (15) $ — $ 19 $ 15 $ (13) $ — $ 69 $ 46 Other Postretirement Benefit Plans Three months ended September 30 Nine months ended September 30 2024 2023 2024 2023 Service cost $ 1 $ — $ 2 $ 1 Interest cost 2 — 2 — Total net periodic benefit cost $ 3 $ — $ 4 $ 1
Schedule of Company Contributions	The Company’s contributions for the three and nine months ended September 30, 2024 and September 30, 2023 , respectively, were as follows: Three months ended Nine months ended September 30, September 30, 2024 2023 2024 2023 Defined Benefit Pension Plans Contributions $ 31 $ 24 $ 86 $ 80 Other Postretirement Benefit Plans Contributions $ 2 $ 1 $ 4 $ 2

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
Earnings Per Share (Tables)	Sep. 30, 2024
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table sets forth the computation of basic and diluted earnings per share: Three months ended Nine months ended September 30, September 30, 2024 2023 2024 2023 Numerator: Net (loss) income attributable to common stockholders $ (150) $ 229 $ 173 $ 777 Denominator: Basic weighted average shares outstanding 508 258 342 258 Effect of dilutive share options — 1 2 1 Diluted weighted average shares outstanding 508 259 344 259 Basic (loss) earnings per share attributable to common stockholders $ (0.30) $ 0.89 $ 0.51 $ 3.01 Diluted (loss) earnings per share attributable to common stockholders $ (0.30) $ 0.88 $ 0.50 $ 3.00
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The following weighted average share-based compensation awards were not included in computing diluted earnings per share because the effect would have been antidilutive: Three months ended Nine months ended September 30, September 30, 2024 2023 2024 2023 Performance stock units 7 — — — Restricted stock units 3 — — — Total antidilutive shares 10 — — —

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	9 Months Ended
Variable Interest Entities (Tables)	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Variable Interest Entities	The carrying amounts of the restricted assets and limited or non-recourse liabilities of Variable Interest Entitie s reported within the Condensed Consolidated Balance Sheets are set out in the following table: September 30, December 31, 2024 2023 Assets Current assets: Cash and cash equivalents, including restricted cash $ 3 $ 3 Accounts receivable 823 816 Non-current assets: Property, plant and equipment, net 41 — Other non-current assets 390 — Total assets $ 1,257 $ 819 Liabilities Current liabilities: Accounts payable $ 7 $ — Current portion of debt 2 — Other current liabilities 2 — Non-current liabilities: Non-current debt due after one year 337 20 Other non-current liabilities 334 — Total liabilities $ 682 $ 20

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Loss (Tables)	9 Months Ended
Accumulated Other Comprehensive Loss (Tables)	Sep. 30, 2024
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	The tables below summarize the changes in accumulated other comprehensive loss by component for the three months ended September 30, 2024 : Foreign Currency Translation Cash Flow Hedges Defined Benefit Pension and Postretirement Plans Other Reserves (2) Total (1) Balance at June 30, 2024 $ 1,056 $ 13 $ 753 $ (751) $ 1,071 Other comprehensive (income) loss (86) — 26 — (60) Balance at September 30, 2024 $ 970 $ 13 $ 779 $ (751) $ 1,011 The tables below summarize the changes in accumulated other comprehensive loss by component for the three months ended September 30, 2023 : Foreign Currency Translation Cash Flow Hedges Defined Benefit Pension and Postretirement Plans Other Reserves (2) Total (1) Balance at June 30, 2023 $ 941 $ 25 $ 754 $ (751) $ 969 Other comprehensive loss (income) 139 (7) (25) — 107 Balance at September 30, 2023 $ 1,080 $ 18 $ 729 $ (751) $ 1,076 The tables below summarize the changes in accumulated other comprehensive loss by component for the nine months ended September 30, 2024 : Foreign Currency Translation Cash Flow Hedges Defined Benefit Pension and Postretirement Plans Other Reserves (2) Total (1) Balance at December 31, 2023 $ 789 $ 16 $ 793 $ (751) $ 847 Other comprehensive loss (income) 181 (3) (14) — 164 Balance at September 30, 2024 $ 970 $ 13 $ 779 $ (751) $ 1,011 The tables below summarize the changes in accumulated other comprehensive loss by component for the nine months ended September 30, 2023 : Foreign Currency Translation Cash Flow Hedges Defined Benefit Pension and Postretirement Plans Other Reserves (2) Total (1) Balance at December 31, 2022 $ 1,199 $ 21 $ 740 $ (751) $ 1,209 Other comprehensive income (119) (3) (11) — (133) Balance at September 30, 2023 $ 1,080 $ 18 $ 729 $ (751) $ 1,076 (1) All amounts are net of tax and noncontrolling interest. (2) This relates to a reverse acquisition reserve which arose on the creation of a new parent of the Company prior to the United Kingdom and Ireland listings.
Schedule of Amounts Recognized in Other Comprehensive Income (Loss)	A summary of the components of other comprehensi ve income (loss) , including noncontrolling interest, for the three months ended September 30, 2024 and September 30, 2023 , is as follows: Three months ended Three months ended September 30, 2024 September 30, 2023 Pre-Tax Tax Net of Tax Pre-Tax Tax Net of Tax Foreign currency translation gain (loss) $ 86 $ — $ 86 $ (139) $ — $ (139) Defined benefit pension and other postretirement benefit plans adjustments: Amortization and settlement recognition of net actuarial loss 9 (1) 8 7 (2) 5 Amortization of prior service credit (1) — (1) (1) — (1) Foreign currency (loss) gain - pensions (33) — (33) 21 — 21 Derivatives: Deferred gain recognized on cash flow hedges — — — 7 — 7 Other comprehensive income (loss) 61 (1) 60 (105) (2) (107) Less: Other comprehensive income (loss) attributable to noncontrolling interests — — — — — — Other comprehensive income (loss) attributable to common stockholders $ 61 $ (1) $ 60 $ (105) $ (2) $ (107) A summary of the components of other comprehensive (loss) income, including noncontrolling interest, for the nine months ended September 30, 2024 and September 30, 2023 , is as follows: Nine months ended Nine months ended September 30, 2024 September 30, 2023 Pre-Tax Tax Net of Tax Pre-Tax Tax Net of Tax Foreign currency translation (loss) gain $ (181) $ — $ (181) $ 119 $ — $ 119 Defined benefit pension and other postretirement benefit plans adjustments: Net actuarial loss arising during period (1) — (1) — — — Amortization and settlement recognition of net actuarial loss 48 (12) 36 23 (6) 17 Amortization of prior service credit (1) — (1) (1) — (1) Foreign currency loss - pensions (20) — (20) (5) — (5) Derivatives: Deferred gain recognized on cash flow hedges 3 — 3 3 — 3 Other comprehensive (loss) income (152) (12) (164) 139 (6) 133 Less: Other comprehensive (loss) income attributable to noncontrolling interests — — — — — — Other comprehensive (loss) income attributable to common stockholders $ (152) $ (12) $ (164) $ 139 $ (6) $ 133

Description of Business and S_3

Description of Business and Summary of Significant Accounting Policies (Details) $ in Millions	Sep. 30, 2024 USD ($)
Supplier Finance Program [Line Items]
Deferred compensation plan assets	$ 181
Deferred compensation liabilities	$ 168
Supplier finance program, payment timing, period	120 days
Supplier finance program, obligation	$ 432
Minimum
Supplier Finance Program [Line Items]
Supplier finance program, terminate agreement, period notice	30 days
Maximum
Supplier Finance Program [Line Items]
Supplier finance program, terminate agreement, period notice	90 days

Acquisitions - Narrative (Detai

Acquisitions - Narrative (Details) $ / shares in Units, $ in Millions			3 Months Ended			9 Months Ended
	Jul. 06, 2024	Jul. 05, 2024 USD ($) $ / shares shares	Sep. 30, 2024 USD ($) $ / shares	Sep. 30, 2024 USD ($) $ / shares	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) $ / shares	Sep. 30, 2023 USD ($)	Jul. 05, 2024 € / shares	Apr. 03, 2024 USD ($)	Dec. 31, 2023 USD ($) $ / shares
Business Acquisition [Line Items]
Common stock, par value (in euro/USD per share) \| $ / shares		$ 0.001	$ 0.001	$ 0.001		$ 0.001				$ 0.001
Goodwill			$ 7,215	$ 7,215		$ 7,215				$ 2,842
Transaction-related costs associated with the Combination				128	$ 17	211	$ 17
Repayments of debt						1,640	120
Payment of accrued interest						(155)	20
Share-based compensation expense				123	7	154	43
Net sales of acquiree since acquisition date			4,684
Net loss of acquiree since acquisition date			132
$750 million senior green notes due 2030
Business Acquisition [Line Items]
Debt instrument, face amount			750	750		750
$1,000 million senior green notes due 2034
Business Acquisition [Line Items]
Debt instrument, face amount			1,000	1,000		1,000
$1,000 million senior green notes due 2054
Business Acquisition [Line Items]
Debt instrument, face amount			$ 1,000	1,000		1,000
Delayed Draw Term Loan (DDTL) \| Line of credit
Business Acquisition [Line Items]
Long-term debt		$ 750
Repayments of debt		750
Payment of accrued interest		$ 1
Senior notes
Business Acquisition [Line Items]
Debt instrument, face amount									$ 2,750
Senior notes \| $750 million senior green notes due 2030
Business Acquisition [Line Items]
Debt instrument, face amount									$ 750
Debt instrument, interest rate									5.20%
Senior notes \| $1,000 million senior green notes due 2034
Business Acquisition [Line Items]
Debt instrument, face amount									$ 1,000
Debt instrument, interest rate									5.438%
Senior notes \| $1,000 million senior green notes due 2054
Business Acquisition [Line Items]
Debt instrument, face amount									$ 1,000
Debt instrument, interest rate									5.777%
Westrock
Business Acquisition [Line Items]
Equity conversion rate		1
Business acquisition, cash consideration, share price (USD per share) \| $ / shares		$ 5
Cash paid for outstanding WestRock Stock		$ 1,291
Shares issued as consideration (in shares) \| shares		258,228,403
Goodwill		$ 4,359
Goodwil deductible amount		187
Accounts receivable acquired		2,374
Business combination, acquired receivables, gross contractual amount		2,429
Business combination, acquired receivables, estimated uncollectible		55
Business combination, recognized identifiable assets, acquired sales-type lease receivable and notes receivable		85
Business combination, acquired sales-type lease receivable and notes receivable, gross contractual amount		107
Business combination, acquired sales-type lease receivable and notes receivable, estimated uncollectible		22
Transaction-related costs associated with the Combination				128	17	211	17
Share-based compensation expense		21
Compensation expense that will be recognized over the remaining service period		$ 162
Service period for recognition of compensation expense not yet recognized	3 years
Accelerated stock compensation expense				44
Net income (loss) attributable to common stockholders				$ 33	$ 324	527	$ (1,486)
Westrock \| Performance stock units
Business Acquisition [Line Items]
Period used for conversion of awards		3 years
Westrock \| Transaction-related Costs
Business Acquisition [Line Items]
Net income (loss) attributable to common stockholders						(450)
Westrock \| Fair value adjustment to inventory
Business Acquisition [Line Items]
Net income (loss) attributable to common stockholders						$ (227)
Westrock \| North America Segment
Business Acquisition [Line Items]
Goodwill		$ 3,990
Westrock \| LATAM Segment
Business Acquisition [Line Items]
Goodwill		207
Westrock \| Europe, MEA And APAC Segment
Business Acquisition [Line Items]
Goodwill		$ 162
Westrock \| Common Stock
Business Acquisition [Line Items]
Business acquisition, equity consideration, shares issued per acquiree share (in shares) \| shares		1
Equity interests issued and issuable		$ 12,098
Westrock \| Converted WestRock Options and WestRock RSU Awards attributable to pre-Combination service
Business Acquisition [Line Items]
Equity interests issued and issuable		$ 101
Smurfit Kappa
Business Acquisition [Line Items]
Common stock, par value (in euro/USD per share) \| € / shares								€ 0.001
Westrock
Business Acquisition [Line Items]
Common stock, par value (in euro/USD per share) \| $ / shares		$ 0.01
Smurfit Kappa Shareholders \| Smurfit WestRock
Business Acquisition [Line Items]
Ownership percentage		50.30%
Westrock Shareholders \| Smurfit WestRock
Business Acquisition [Line Items]
Ownership percentage		49.70%

Acquisitions - Schedule of Merg

Acquisitions - Schedule of Merger Consideration (Details) $ / shares in Units, $ in Millions	Jul. 05, 2024 USD ($) shares	Sep. 30, 2024 shares	Jul. 05, 2024 £ / shares $ / £ shares	Jul. 05, 2024 $ / shares $ / £ shares	Dec. 31, 2023 shares
Business Acquisition [Line Items]
Common stock, shares outstanding (in shares) \| shares		520,056,084			260,354,342
Westrock
Business Acquisition [Line Items]
Common stock, shares outstanding (in shares) \| shares			258,228,403	258,228,403
Westrock
Business Acquisition [Line Items]
Business acquisition, share price (GBP per share) \| £ / shares			£ 36.56
Cash paid for outstanding WestRock Stock	$ 1,291
Settlement of pre-existing relationships, trade and other payable and receivable balances with WestRock	(29)
Aggregate Merger Consideration	$ 13,461
Shares issued as consideration (in shares) \| shares	258,228,403
Business acquisition, cash consideration, share price (USD per share) \| $ / shares				$ 5
Foreign currency exchange rate, translation (in USD per GBP) \| $ / £			1.2815	1.2815
Westrock \| Accounts Receivable
Business Acquisition [Line Items]
Settlement of pre-existing relationships, trade and other payable and receivable balances with WestRock	$ 3
Westrock \| Accounts Payable
Business Acquisition [Line Items]
Settlement of pre-existing relationships, trade and other payable and receivable balances with WestRock	(32)
Westrock \| Smurfit Westrock Shares issued to WestRock Stockholders
Business Acquisition [Line Items]
Equity interests issued and issuable	12,098
Westrock \| Converted WestRock Options and WestRock RSU Awards attributable to pre-Combination service
Business Acquisition [Line Items]
Equity interests issued and issuable	$ 101

Acquisitions - Schedule of Reco

Acquisitions - Schedule of Recognized Identified Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Millions	Sep. 30, 2024	Jul. 05, 2024	Dec. 31, 2023
Business Acquisition [Line Items]
Goodwill	$ 7,215		$ 2,842
Westrock
Business Acquisition [Line Items]
Cash and cash equivalents		$ 603
Accounts receivable		2,374
Inventories		2,504
Other current assets		825
Property, plant and equipment		17,567
Intangibles		922
Prepaid pension asset		558
Other non-current assets		1,765
Accounts payable		(2,018)
Accrued compensation and benefits		(447)
Current portion of debt		(1,285)
Other current liabilities		(1,123)
Non-current debt due after one year		(7,438)
Deferred tax liabilities		(3,523)
Pension liabilities and other postretirement benefits, net of current portion		(299)
Other non-current liabilities		(1,872)
Noncontrolling interests		(11)
Identifiable net assets acquired as of July 5, 2024		9,102
Goodwill		4,359
Aggregate Merger Consideration		$ 13,461

Acquisitions - Schedule of Fini

Acquisitions - Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination (Details) - Westrock $ in Millions	Jul. 05, 2024 USD ($)
Acquired Finite-Lived Intangible Assets [Line Items]
Preliminary Fair Value	$ 922
Weighted Average Useful Lives (in years)	10 years
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Preliminary Fair Value	$ 417
Weighted Average Useful Lives (in years)	10 years
Trade names and trademarks
Acquired Finite-Lived Intangible Assets [Line Items]
Preliminary Fair Value	$ 228
Weighted Average Useful Lives (in years)	10 years
Developed technology
Acquired Finite-Lived Intangible Assets [Line Items]
Preliminary Fair Value	$ 179
Weighted Average Useful Lives (in years)	12 years
Software assets
Acquired Finite-Lived Intangible Assets [Line Items]
Preliminary Fair Value	$ 94
Weighted Average Useful Lives (in years)	5 years
Land use rights
Acquired Finite-Lived Intangible Assets [Line Items]
Preliminary Fair Value	$ 4
Weighted Average Useful Lives (in years)	22 years

Acquisitions - Pro Forma Inform

Acquisitions - Pro Forma Information (Details) - Westrock - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Business Acquisition [Line Items]
Net sales	$ 7,931	$ 7,925	$ 23,381	$ 24,688
Net income (loss) attributable to common stockholders	$ 33	$ 324	$ 527	$ (1,486)

Segment Information - Narrative

Segment Information - Narrative (Details) $ in Millions	3 Months Ended	9 Months Ended
Segment Information - Narrative (Details) $ in Millions	Sep. 30, 2024 USD ($) segment	Sep. 30, 2024 USD ($)
Segment Reporting [Abstract]
Number of operating segments \| segment	3
Number of reportable segments \| segment	3
Restructuring costs	$ 19	$ 19
Losses at closed facilities	8	8
Other asset impairment charges	$ 2	2
Regulatory fines reimbursement		$ 18

Segment Information - Reconcili

Segment Information - Reconciliation of Operating Profit (Loss) from Segments to Consolidated (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales	$ 7,671	$ 2,915	$ 13,570	$ 9,231
Adjusted EBITDA	1,307	551	2,315	1,756
Unallocated corporate costs	(42)	(26)	(95)	(74)
Depreciation, depletion and amortization	(564)	(147)	(872)	(430)
Interest expense, net	167	39	225	109
Pension and other postretirement non-service benefit (expense), net	8	(9)	(31)	(29)
Share-based compensation expense	(123)	(7)	(154)	(43)
Other expense, net	(13)	(4)	(13)	(19)
Amortization of fair value step up on inventory	(227)	0	(227)	0
Transaction and integration-related expenses associated with the Combination	(267)	(17)	(350)	(17)
Other adjustments	(29)	0	(11)	0
(Loss) income before income taxes	(117)	302	337	1,035
Europe, MEA and APAC
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales	2,646	2,188	7,043	7,038
North America
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales	4,531	401	5,380	1,239
LATAM
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales	494	326	1,147	954
Operating segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales	7,806	2,933	13,742	9,286
Operating segments \| Europe, MEA and APAC
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales	2,651	2,191	7,056	7,047
Adjusted EBITDA	411	411	1,158	1,330
Operating segments \| North America
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales	4,649	401	5,499	1,239
Adjusted EBITDA	780	66	900	209
Operating segments \| LATAM
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales	506	341	1,187	1,000
Adjusted EBITDA	116	74	257	217
Intersegment eliminations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales	135	18	172	55
Intersegment eliminations \| Europe, MEA and APAC
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales	5	3	13	9
Intersegment eliminations \| North America
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales	118	0	119	0
Intersegment eliminations \| LATAM
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales	$ 12	$ 15	$ 40	$ 46

Segment Information - Schedule

Segment Information - Schedule of Segment Reporting Information, by Segment (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Segment Reporting, Asset Reconciling Item [Line Items]
Total capital expenditure	$ 897	$ 661
Total assets	45,029		$ 14,051
Operating segments
Segment Reporting, Asset Reconciling Item [Line Items]
Total capital expenditure	880	655
Total assets	44,189		12,923
Operating segments \| Europe, MEA and APAC
Segment Reporting, Asset Reconciling Item [Line Items]
Total capital expenditure	353	411
Total assets	11,408		9,521
Operating segments \| North America
Segment Reporting, Asset Reconciling Item [Line Items]
Total capital expenditure	373	96
Total assets	29,343		1,607
Operating segments \| LATAM
Segment Reporting, Asset Reconciling Item [Line Items]
Total capital expenditure	154	148
Total assets	3,438		1,795
Corporate
Segment Reporting, Asset Reconciling Item [Line Items]
Total capital expenditure	17	$ 6
Total assets	$ 840		$ 1,128

Revenue Recognition - Schedule

Revenue Recognition - Schedule of disaggregated revenue with unaffiliated customers (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Disaggregation of Revenue [Line Items]
Net sales	$ 7,671	$ 2,915	$ 13,570	$ 9,231
Europe, MEA and APAC
Disaggregation of Revenue [Line Items]
Net sales	2,646	2,188	7,043	7,038
North America
Disaggregation of Revenue [Line Items]
Net sales	4,531	401	5,380	1,239
LATAM
Disaggregation of Revenue [Line Items]
Net sales	494	326	1,147	954
Paper
Disaggregation of Revenue [Line Items]
Net sales	1,551	372	2,330	1,173
Paper \| Europe, MEA and APAC
Disaggregation of Revenue [Line Items]
Net sales	402	333	1,092	1,054
Paper \| North America
Disaggregation of Revenue [Line Items]
Net sales	1,107	25	1,165	81
Paper \| LATAM
Disaggregation of Revenue [Line Items]
Net sales	42	14	73	38
Packaging
Disaggregation of Revenue [Line Items]
Net sales	6,120	2,543	11,240	8,058
Packaging \| Europe, MEA and APAC
Disaggregation of Revenue [Line Items]
Net sales	2,244	1,855	5,951	5,984
Packaging \| North America
Disaggregation of Revenue [Line Items]
Net sales	3,424	376	4,215	1,158
Packaging \| LATAM
Disaggregation of Revenue [Line Items]
Net sales	$ 452	$ 312	$ 1,074	$ 916

Revenue Recognition - Rollforwa

Revenue Recognition - Rollforward Contract Assets and Liabilities (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2024	Jul. 05, 2024
Revenue from Contract with Customer [Abstract]
Contract assets and liabilities assumed in the combination, contract assets (short-term)	$ 203	$ 220
Contract assets and liabilities assumed in the combination, contract assets (short-term), increase (decrease)	(17)
Contract assets and liabilities assumed in the combination, contract liabilities (short-term),	6	$ 10
Contract assets and liabilities assumed in the combination, contract liabilities (short-term), increase (decrease)	$ (4)

Transaction and integration-c_3

Transaction and integration-costs associated with the Combination (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Equity Method Investments and Joint Ventures [Abstract]
Transaction-related costs associated with the Combination	$ (128)	$ (17)	$ (211)	$ (17)
Integration-related costs associated with the Combination	(139)	0	(139)	0
Transaction and integration-related expenses associated with the Combination	$ (267)	$ (17)	$ (350)	$ (17)

Accounts Receivable (Details)

Accounts Receivable (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Receivables [Abstract]
Gross accounts receivable	$ 4,830	$ 1,976
Less: Allowances	(217)	(170)
Accounts receivable	$ 4,613	$ 1,806

Inventories (Details)

Inventories (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Inventory Disclosure [Abstract]
Finished goods	$ 1,364	$ 514
Work in process	240	52
Raw materials	1,378	348
Consumables and spare parts	603	289
Inventories	$ 3,585	$ 1,203

Property, Plant, and Equipmen_2

Property, Plant, and Equipment - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Finance lease right-of-use assets	$ 422	$ 32
Property, plant and equipment at cost	30,374	12,305
Less: Accumulated depreciation, depletion and amortization	(7,168)	(6,514)
Property, plant and equipment, net	23,206	5,791
Land and buildings
Property, Plant and Equipment [Line Items]
Property, plant and equipment at cost	5,531	2,679
Forestlands
Property, Plant and Equipment [Line Items]
Property, plant and equipment at cost	272	78
Plant and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment at cost	22,684	8,860
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment at cost	$ 1,465	$ 656

Property, Plant, and Equipmen_3

Property, Plant, and Equipment - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Property, Plant and Equipment [Abstract]
Depreciation	$ 517	$ 134	$ 802	$ 392

Goodwill - Schedule of Goodwill

Goodwill - Schedule of Goodwill (Details) $ in Millions	9 Months Ended
Goodwill - Schedule of Goodwill (Details) $ in Millions	Sep. 30, 2024 USD ($)
Goodwill [Roll Forward]
Goodwill gross, beginning balance	$ 3,106
Accumulated impairment losses, beginning balance	(264)
Goodwill, beginning balance	2,842
Acquisitions	4,368
Translation adjustment	5
Goodwill gross, ending balance	7,477
Accumulated impairment losses, ending balance	(262)
Goodwill, ending balance	7,215
Europe, MEA and APAC
Goodwill [Roll Forward]
Goodwill gross, beginning balance	2,653
Accumulated impairment losses, beginning balance	(209)
Goodwill, beginning balance	2,444
Acquisitions	171
Translation adjustment	33
Goodwill gross, ending balance	2,860
Accumulated impairment losses, ending balance	(212)
Goodwill, ending balance	2,648
North America
Goodwill [Roll Forward]
Goodwill gross, beginning balance	264
Accumulated impairment losses, beginning balance	0
Goodwill, beginning balance	264
Acquisitions	3,990
Translation adjustment	(15)
Goodwill gross, ending balance	4,239
Accumulated impairment losses, ending balance	0
Goodwill, ending balance	4,239
LATAM
Goodwill [Roll Forward]
Goodwill gross, beginning balance	189
Accumulated impairment losses, beginning balance	(55)
Goodwill, beginning balance	134
Acquisitions	207
Translation adjustment	(13)
Goodwill gross, ending balance	378
Accumulated impairment losses, ending balance	(50)
Goodwill, ending balance	$ 328

Goodwill - Narrative (Details)

Goodwill - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2024	Jul. 05, 2024	Dec. 31, 2023
Goodwill [Line Items]
Goodwill	$ 7,215		$ 2,842
Westrock
Goodwill [Line Items]
Goodwill		$ 4,359

Fair Value Measurement - Fair V

Fair Value Measurement - Fair Value Measurements, Recurring and Nonrecurring (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Book Value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt with fixed interest rates, book value	$ 11,274	$ 3,615
Level 2 \| Fair Value
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Debt with fixed interest rates, fair value	$ 11,414	$ 3,379

Fair Value Measurement - Schedu

Fair Value Measurement - Schedule of fair value, Assets and Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Level 1
Other Investments:
Assets measured at fair value	$ 2	$ 2
Liabilities
Liabilities measured at fair value	0	0
Level 1 \| Listed
Other Investments:
Derivative Asset, Subject to Master Netting Arrangement, before Offset	2	2
Level 1 \| Unlisted
Other Investments:
Derivative Asset, Subject to Master Netting Arrangement, before Offset	0	0
Level 1 \| Derivatives in cash flow hedging relationships
Other Investments:
Derivatives in cash flow hedging relationships	0	0
Liabilities
Derivatives in cash flow hedging relationships	0	0
Level 1 \| Derivatives not designated as hedging instruments
Other Investments:
Derivatives not designated as hedging instruments	0	0
Liabilities
Derivatives not designated as hedging instruments	0	0
Level 2
Other Investments:
Assets measured at fair value	30	28
Liabilities
Liabilities measured at fair value	7	20
Level 2 \| Listed
Other Investments:
Derivative Asset, Subject to Master Netting Arrangement, before Offset	0	0
Level 2 \| Unlisted
Other Investments:
Derivative Asset, Subject to Master Netting Arrangement, before Offset	10	9
Level 2 \| Derivatives in cash flow hedging relationships
Other Investments:
Derivatives in cash flow hedging relationships	2	5
Liabilities
Derivatives in cash flow hedging relationships	6	8
Level 2 \| Derivatives not designated as hedging instruments
Other Investments:
Derivatives not designated as hedging instruments	18	14
Liabilities
Derivatives not designated as hedging instruments	$ 1	$ 12

Fair Value Measurement - Narrat

Fair Value Measurement - Narrative (Details) BTU in Millions, $ in Millions	9 Months Ended
	Sep. 30, 2024 USD ($) BTU
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Natural gas commodity program, notional amount, heating content \| BTU	10
Receivables sold under these accounts receivable monetization agreements	$ 711
Expense related to sale of receivables	12
700 Million Receivable Monetization Facility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Maximum eligible receivables that may be sold	700
110 Million Receivable Monetization Facility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Maximum eligible receivables that may be sold	$ 110

Fair Value Measurement - Accoun

Fair Value Measurement - Accounts Receivable Monetization Agreements (Details) $ in Millions	Sep. 30, 2024 USD ($)
Fair Value Disclosures [Abstract]
Receivable from financial institutions recognized as part of Combination	$ 0
Receivables sold to the financial institutions and derecognized	670
Receivables collected by financial institutions	621
Cash proceeds from financial institutions	49
Receivable from financial institutions at September 30, 2024	$ 0

Debt (Details)

Debt (Details) - USD ($) $ in Millions	Sep. 30, 2024	Jun. 28, 2024	Apr. 03, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Finance lease obligations	$ 542			$ 29
Total debt, excluding debt issuance costs	13,964			3,769
Debt issuance costs	(45)			(22)
Total debt	13,919			3,747
Less: Current portion of debt	(745)			(78)
Non-current debt due after one year	13,174			3,669
Smurfit Kappa, Prior Combination
Debt Instrument [Line Items]
Bank loans	110			68
Finance lease obligations	27			29
Bank overdrafts	8			16
The Combination
Debt Instrument [Line Items]
Long-term debt	42			0
Finance lease obligations	515			0
€100 million receivables securitization variable funding notes due 2026
Debt Instrument [Line Items]
Debt instrument, face amount	100
€100 million receivables securitization variable funding notes due 2026 \| Smurfit Kappa, Prior Combination
Debt Instrument [Line Items]
Long-term debt	112			6
€230 million receivables securitization variable funding notes due 2026
Debt Instrument [Line Items]
Debt instrument, face amount	230
€230 million receivables securitization variable funding notes due 2026 \| Smurfit Kappa, Prior Combination
Debt Instrument [Line Items]
Long-term debt	223			14
$292.3 million senior debentures due 2025
Debt Instrument [Line Items]
Debt instrument, face amount	292.3
€250 million senior notes due 2025
Debt Instrument [Line Items]
Debt instrument, face amount	250
€1,000 million senior notes due 2026
Debt Instrument [Line Items]
Debt instrument, face amount	1,000
€750 million senior notes due 2027
Debt Instrument [Line Items]
Debt instrument, face amount	750
€500 million senior green notes due 2029
Debt Instrument [Line Items]
Debt instrument, face amount	500
$750 million senior green notes due 2030
Debt Instrument [Line Items]
Debt instrument, face amount	750
€500 million senior green notes due 2033
Debt Instrument [Line Items]
Debt instrument, face amount	500
$1,000 million senior green notes due 2034
Debt Instrument [Line Items]
Debt instrument, face amount	1,000
$1,000 million senior green notes due 2054
Debt Instrument [Line Items]
Debt instrument, face amount	1,000
$750 million senior notes due 2026
Debt Instrument [Line Items]
Debt instrument, face amount	750
$500 million senior notes due 2027
Debt Instrument [Line Items]
Debt instrument, face amount	500
$600 million senior notes due 2028
Debt Instrument [Line Items]
Debt instrument, face amount	600
$500 million senior notes due 2028
Debt Instrument [Line Items]
Debt instrument, face amount	500
$750 million senior notes due 2029
Debt Instrument [Line Items]
Debt instrument, face amount	750
$400 million senior notes due 2030
Debt Instrument [Line Items]
Debt instrument, face amount	400
$300 million senior notes due 2031
Debt Instrument [Line Items]
Debt instrument, face amount	300
$500 million senior notes due 2032
Debt Instrument [Line Items]
Debt instrument, face amount	500
$76 million senior notes due 2032
Debt Instrument [Line Items]
Debt instrument, face amount	76
$600 million senior notes due 2033
Debt Instrument [Line Items]
Debt instrument, face amount	600
$3 million senior notes due 2037
Debt Instrument [Line Items]
Debt instrument, face amount	3
$150 million senior notes due 2047
Debt Instrument [Line Items]
Debt instrument, face amount	150
$700 million receivables securitization due 2027
Debt Instrument [Line Items]
Debt instrument, face amount	700
$700 million receivables securitization due 2027 \| The Combination
Debt Instrument [Line Items]
Long-term debt	525			0
Senior notes
Debt Instrument [Line Items]
Debt instrument, face amount			$ 2,750
Senior notes \| $292.3 million senior debentures due 2025 \| Smurfit Kappa, Prior Combination
Debt Instrument [Line Items]
Long-term debt	292			294
Senior notes \| €250 million senior notes due 2025 \| Smurfit Kappa, Prior Combination
Debt Instrument [Line Items]
Long-term debt	0			279
Senior notes \| €1,000 million senior notes due 2026 \| Smurfit Kappa, Prior Combination
Debt Instrument [Line Items]
Long-term debt	1,117			1,121
Senior notes \| €750 million senior notes due 2027 \| Smurfit Kappa, Prior Combination
Debt Instrument [Line Items]
Long-term debt	837			832
Senior notes \| €500 million senior green notes due 2029 \| Smurfit Kappa, Prior Combination
Debt Instrument [Line Items]
Long-term debt	557			553
Senior notes \| $750 million senior green notes due 2030
Debt Instrument [Line Items]
Debt instrument, face amount			750
Senior notes \| $750 million senior green notes due 2030 \| Smurfit Kappa, Prior Combination
Debt Instrument [Line Items]
Long-term debt	749			0
Senior notes \| €500 million senior green notes due 2033 \| Smurfit Kappa, Prior Combination
Debt Instrument [Line Items]
Long-term debt	557			553
Senior notes \| $1,000 million senior green notes due 2034
Debt Instrument [Line Items]
Debt instrument, face amount			1,000
Senior notes \| $1,000 million senior green notes due 2034 \| Smurfit Kappa, Prior Combination
Debt Instrument [Line Items]
Long-term debt	1,000			0
Senior notes \| $1,000 million senior green notes due 2054
Debt Instrument [Line Items]
Debt instrument, face amount			$ 1,000
Senior notes \| $1,000 million senior green notes due 2054 \| Smurfit Kappa, Prior Combination
Debt Instrument [Line Items]
Long-term debt	1,000			0
Senior notes \| $750 million senior notes due 2026 \| The Combination
Debt Instrument [Line Items]
Long-term debt	742			0
Senior notes \| $500 million senior notes due 2027 \| The Combination
Debt Instrument [Line Items]
Long-term debt	477			0
Senior notes \| $600 million senior notes due 2028 \| The Combination
Debt Instrument [Line Items]
Long-term debt	578			0
Senior notes \| $500 million senior notes due 2028 \| The Combination
Debt Instrument [Line Items]
Long-term debt	480			0
Senior notes \| $750 million senior notes due 2029 \| The Combination
Debt Instrument [Line Items]
Long-term debt	749			0
Senior notes \| $400 million senior notes due 2030 \| The Combination
Debt Instrument [Line Items]
Long-term debt	456			0
Senior notes \| $300 million senior notes due 2031 \| The Combination
Debt Instrument [Line Items]
Long-term debt	341			0
Senior notes \| $500 million senior notes due 2032 \| The Combination
Debt Instrument [Line Items]
Long-term debt	472			0
Senior notes \| $76 million senior notes due 2032 \| The Combination
Debt Instrument [Line Items]
Long-term debt	82			0
Senior notes \| $600 million senior notes due 2033 \| The Combination
Debt Instrument [Line Items]
Long-term debt	512			0
Senior notes \| $3 million senior notes due 2037 \| The Combination
Debt Instrument [Line Items]
Long-term debt	3			0
Senior notes \| $150 million senior notes due 2047 \| The Combination
Debt Instrument [Line Items]
Long-term debt	175			0
Commercial paper \| The Combination
Debt Instrument [Line Items]
Long-term debt	512			0
Vendor financing and commercial card programs \| The Combination
Debt Instrument [Line Items]
Long-term debt	114			0
Revolving Credit Facility \| Line of credit \| Smurfit Kappa, Prior Combination
Debt Instrument [Line Items]
Long-term debt	0			4
Secured Debt \| Line of credit
Debt Instrument [Line Items]
Debt instrument, face amount		$ 600
Secured Debt \| Line of credit \| The Combination
Debt Instrument [Line Items]
Long-term debt	$ 600			$ 0

Debt - Narrative (Details)

Debt - Narrative (Details) € in Millions, $ in Millions	Sep. 17, 2024 USD ($)	Aug. 12, 2024 USD ($)	Aug. 12, 2024 EUR (€)	Sep. 30, 2024 USD ($)
Debt Instrument [Line Items]
Unamortized fair value adjustment from combination				$ 58
Weighted average remaining life, unamortized fair market value adjustment				7 years 4 months 24 days
Senior notes due Feb 2025 \| Senior notes
Debt Instrument [Line Items]
Extinguishment of debt, amount \| €			€ 250
Gain (loss) on extinguishment of debt		$ 0
Senior notes due March 2025 \| Senior notes
Debt Instrument [Line Items]
Extinguishment of debt, amount	$ 600
Gain (loss) on extinguishment of debt	$ 4
Debt instrument, interest rate	3.75%

Debt - New Credit Agreement Nar

Debt - New Credit Agreement Narrative (Details) € in Millions, $ in Millions	Jul. 05, 2024 USD ($)	Jul. 05, 2024 EUR (€)	Jul. 02, 2024 USD ($)	Jun. 28, 2024 USD ($)
Swingline Sub-Facility
Debt Instrument [Line Items]
Debt instrument, face amount				$ 500
Secured Debt \| Line of credit
Debt Instrument [Line Items]
Debt instrument, face amount				600
Extinguishment of debt, amount			$ 600
Secured Debt \| Swingline Sub-Facility
Debt Instrument [Line Items]
Debt instrument, face amount				500
Revolving Credit Facility
Debt Instrument [Line Items]
Extinguishment of debt, amount \| €		€ 1,350
Gain (loss) on extinguishment of debt	$ 0
Revolving Credit Facility \| Multicurrency Revolving Loan Facility
Debt Instrument [Line Items]
Multicurrency revolving loan facility				$ 4,500

Debt - Term loan facilities Nar

Debt - Term loan facilities Narrative (Details) - USD ($) $ in Millions		9 Months Ended
	Jul. 05, 2024	Sep. 30, 2024	Sep. 30, 2023
Debt Instrument [Line Items]
Repayments of debt		$ 1,640	$ 120
Senior Unsecured Term Loan \| Farm Credit Facility
Debt Instrument [Line Items]
Debt instrument, face amount		600
Long-term debt		$ 600
Senior Unsecured Term Loan \| Farm Credit Facility \| Term SOFR
Debt Instrument [Line Items]
Debt instrument, credit spread adjustment		0.001
Senior Unsecured Term Loan \| Farm Credit Facility \| Minimum \| Term SOFR
Debt Instrument [Line Items]
Debt instrument, spread on variable rate		1.65%
Senior Unsecured Term Loan \| Farm Credit Facility \| Minimum \| Alternate Rate Base
Debt Instrument [Line Items]
Debt instrument, spread on variable rate		0.65%
Senior Unsecured Term Loan \| Farm Credit Facility \| Maximum \| Term SOFR
Debt Instrument [Line Items]
Debt instrument, spread on variable rate		2.275%
Senior Unsecured Term Loan \| Farm Credit Facility \| Maximum \| Alternate Rate Base
Debt Instrument [Line Items]
Debt instrument, spread on variable rate		1.275%
Line of credit \| Delayed Draw Term Loan (DDTL)
Debt Instrument [Line Items]
Long-term debt	$ 750
Repayments of debt	$ 750

Debt - Receivables Securitizati

Debt - Receivables Securitization Facility Narrative (Details) € in Millions, $ in Millions	Sep. 30, 2024 EUR (€)	Sep. 30, 2024 USD ($)	Dec. 31, 2023 EUR (€)	Dec. 31, 2023 USD ($)
€100 million receivables securitization variable funding notes due 2026
Debt Instrument [Line Items]
Accounts receivable from securitization \| €	€ 100
Security owned and pledged as collateral, associated liabilities, fair value \| €	317		€ 327
Transferors interests in transferred financial assets maximum investment limit		$ 0		$ 105
€230 million receivables securitization variable funding notes due 2026
Debt Instrument [Line Items]
Accounts receivable from securitization \| €	230
Security owned and pledged as collateral, associated liabilities, fair value \| €	€ 422		€ 415
Transferors interests in transferred financial assets maximum investment limit		34		$ 240
$700 million receivables securitization due 2027
Debt Instrument [Line Items]
Transferors interests in transferred financial assets maximum investment limit		175
Transferor's interests in transferred financial assets, fair value		700
Transfers Accounted for as Secured Borrowings, Assets, Carrying Amount		$ 1,137

Debt - Commercial Paper Narrati

Debt - Commercial Paper Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2024	Jun. 28, 2024
Debt Instrument [Line Items]
Debt, weighted average interest rate	5.20%
Swingline Sub-Facility
Debt Instrument [Line Items]
Debt instrument, face amount		$ 500
Commercial paper \| Unsecured Debt
Debt Instrument [Line Items]
Multicurrency revolving loan facility	$ 1,000
Multicurrency Revolving Loan Facility \| Revolving Credit Facility
Debt Instrument [Line Items]
Multicurrency revolving loan facility		$ 4,500
Senior Unsecured Commercial Paper Note \| Commercial paper
Debt Instrument [Line Items]
Aggregate principal amount	$ 512

Leases - Schedule of Components

Leases - Schedule of Components of Lease Costs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Leases [Abstract]
Operating lease costs	$ (95)	$ (31)	$ (168)	$ (87)
Variable and short-term lease costs	(53)	(10)	(72)	(35)
Finance lease cost:
Amortization of lease assets	(23)	(1)	(25)	(2)
Interest on lease liabilities	(11)	0	(12)	(1)
Lease cost	$ (182)	$ (42)	$ (277)	$ (125)

Leases - Schedule of Supplement

Leases - Schedule of Supplemental Balance Sheet Information Related to Leases (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Operating leases:
Operating lease right-of-use assets	$ 985	$ 374
Current operating lease liabilities	$ 306	113
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Other current liabilities
Non-current operating lease liabilities	$ 706	269
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other non-current liabilities (amounts related to consolidated variable interest entities of $334 million and $— at September 30, 2024 and December 31, 2023, respectively)
Total operating lease liabilities	$ 1,012	382
Finance leases:
Property, Plant and Equipment	422	32
Accumulated depreciation	(25)	(6)
Property, Plant and Equipment, net	397	26
Current finance lease liabilities	$ 32	3
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Current portion of debt
Non-current finance lease liabilities	$ 510	26
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Non-current debt due after one year (amounts related to consolidated variable interest entities of $337 million and $20 million at September 30, 2024 and December 31, 2023, respectively)
Total finance lease liabilities	$ 542	$ 29

Leases - Narrative (Details)

Leases - Narrative (Details) - Westrock $ in Millions	9 Months Ended
Leases - Narrative (Details) - Westrock $ in Millions	Sep. 30, 2024 USD ($)
Lessee, Lease, Description [Line Items]
Increase in operating lease right-of-use assets	$ 659
Increase in operating lease liability	662
Increase in finance lease right-of-use assets	388
Increase in finance lease liability	$ 512

Leases - Schedule of Suppleme_2

Leases - Schedule of Supplemental Cash Flow Information Related to Leases (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Leased assets obtained in exchange for lease liabilities:
Operating leases	$ 125	$ 68
Finance leases	$ 2	$ 0

Interest (Details)

Interest (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
Interest (Details) - USD ($) $ in Millions	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Interest Income (Expense), Nonoperating [Abstract]
Interest expense	$ (209)	$ (46)	$ (321)	$ (129)
Interest income	42	7	96	20
Interest expense, net	$ (167)	$ (39)	(225)	(109)
Cash paid for interest, net of interest received			236	123
Interest costs capitalized			$ 11	$ 9

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
Income Taxes (Details) - USD ($) $ in Millions	Jul. 05, 2024	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Effective tax rate percentage		(28.20%)	24.20%	48.70%	24.90%
Net income taxes paid				$ 229	$ 308
Unrecognized tax benefits from acquisition	$ 520

Retirement Plans - Schedule of

Retirement Plans - Schedule of Net Benefit Costs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Other Postretirement Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 1	$ 0	$ 2	$ 1
Interest cost	2	0	2	0
Total net periodic benefit (income) cost	3	0	4	1
U.S. Plans \| Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	5	0	5	0
Interest cost	50	1	53	2
Expected return on assets	(70)	(1)	(71)	(2)
Net actuarial loss	0	0	0	0
Prior service credit	0	0	0	0
Settlement loss	0	0	0	0
Total net periodic benefit (income) cost	(15)	0	(13)	0
Non-U.S. Plans \| Defined Benefit Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	9	6	22	17
Interest cost	36	24	78	69
Expected return on assets	(34)	(21)	(78)	(62)
Net actuarial loss	9	7	29	23
Prior service credit	(1)	(1)	(1)	(1)
Settlement loss	0	0	19	0
Total net periodic benefit (income) cost	$ 19	$ 15	$ 69	$ 46

Retirement Plans - Narrative (D

Retirement Plans - Narrative (Details) - Westrock - USD ($) $ in Millions	1 Months Ended		12 Months Ended
	Apr. 30, 2020	Feb. 28, 2020	Dec. 31, 2024	Sep. 30, 2024	Jul. 05, 2024
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, net pension assets					$ 234
Defined benefit plan, benefit obligation					4,931
Defined benefit plan, plan assets					5,165
Withdrawal liabilities				$ 212	$ 211
Pace Industry Union Management Pension Fund
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Damages sought	$ 1	$ 51
Forecast
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets, contributions by employer			$ 17

Retirement Plans - Schedule o_2

Retirement Plans - Schedule of Company Contributions (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Pension Plans Contributions	$ 31	$ 24	$ 86	$ 80
Other Postretirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Pension Plans Contributions	$ 2	$ 1	$ 4	$ 2

Earnings Per Share - Basic and

Earnings Per Share - Basic and diluted earnings per share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Numerator:
Net (loss) income attributable to common stockholders	$ (150)	$ 229	$ 173	$ 777
Net (loss) income attributable to common stockholders	$ (150)	$ 229	$ 173	$ 777
Denominator:
Basic weighted average shares outstanding (in shares)	508	258	342	258
Effect of dilutive share options (in shares)	0	1	2	1
Diluted weighted average shares outstanding (in shares)	508	259	344	259
Earnings Per Share, Basic and Diluted EPS [Abstract]
Basic (loss) earnings per share attributable to common stockholders (in USD per share)	$ (0.30)	$ 0.89	$ 0.51	$ 3.01
Diluted (loss) earnings per share attributable to common stockholders (in USD per share)	$ (0.30)	$ 0.88	$ 0.50	$ 3

Earnings Per Share - Antidiluti

Earnings Per Share - Antidilutive securities (Details) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	10	0	0	0
Performance stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	7	0	0	0
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	3	0	0	0

Commitments and Contingencies (

Commitments and Contingencies (Details) R$ in Millions, $ in Millions			9 Months Ended		12 Months Ended
	Aug. 28, 2024 USD ($)	Mar. 07, 2024 USD ($)	Sep. 30, 2024 BRL (R$)	Sep. 30, 2024 USD ($) subsidiary lawsuit proceeding	Dec. 31, 2021 USD ($)	Aug. 31, 2019 defendant
Asbestos Litigation
Loss Contingencies [Line Items]
Number of lawsuits \| lawsuit				625
Accrual for pending claims and litigation costs				$ 73
Loss contingency, estimated insurance recovery				$ 46
Italian Competition Authority Investigation
Loss Contingencies [Line Items]
Litigation, total number of companies \| defendant						30
Fine paid					$ 138
Reduction in fine		$ (18)
International Arbitration Against Venezuela
Loss Contingencies [Line Items]
Compensation awarded	$ 469
Legal costs awarded	$ 5
Secretariat of the Federal Revenue Bureau of Brazil \| Brazil Tax Liability
Loss Contingencies [Line Items]
Merger, number of subsidiaries \| subsidiary				2
Number of proceedings \| proceeding				2
Damages sought			R$ 745	$ 137

Variable Interest Entities - Na

Variable Interest Entities - Narrative (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Variable Interest Entity [Line Items]
Total assets	$ 45,029		$ 14,051
Total liabilities	27,037		7,877
Proceeds from issuance of debt	$ 3,127	$ 77
GPS
Variable Interest Entity [Line Items]
Ownership percentage in joint venture	48%
SP Fiber
Variable Interest Entity [Line Items]
Percentage ownership	100%
Variable interest entity, primary beneficiary
Variable Interest Entity [Line Items]
Total assets	$ 1,257		819
Total liabilities	682		$ 20
Proceeds from issuance of debt	338
Unrestricted cash	2
Variable interest entity, primary beneficiary \| Recourse
Variable Interest Entity [Line Items]
Total liabilities	336
Variable interest entity, primary beneficiary \| Asset pledged as collateral
Variable Interest Entity [Line Items]
Total assets	$ 821

Variable Interest Entities - Sc

Variable Interest Entities - Schedule of Variable Interest Entities (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023	Sep. 30, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents, including restricted cash	$ 951	$ 1,000	$ 729	$ 841
Accounts receivable	4,613	1,806
Non-current assets:
Property, plant and equipment, net	23,206	5,791
Other non-current assets	2,354	601
Total assets	45,029	14,051
Current liabilities:
Accounts payable	3,357	1,728
Current portion of debt	745	78
Other current liabilities	1,257	484
Non-current liabilities:
Other non-current liabilities	2,267	385
Total liabilities	27,037	7,877
Variable interest entity, primary beneficiary
Current assets:
Cash and cash equivalents, including restricted cash	3	3
Accounts receivable	823	816
Non-current assets:
Property, plant and equipment, net	41	0
Other non-current assets	390	0
Total assets	1,257	819
Current liabilities:
Accounts payable	7	0
Current portion of debt	2	0
Other current liabilities	2	0
Non-current liabilities:
Non-current debt due after one year	337	20
Other non-current liabilities	334	0
Total liabilities	$ 682	$ 20

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Loss - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
AOCI Including Portion Attributable to Noncontrolling Interest [Abstract]
Balance, beginning of period			$ (847)
Other comprehensive (income) loss	$ (60)	$ 107	164	$ (133)
Balance, end of period	(1,011)		(1,011)
Total
AOCI Including Portion Attributable to Noncontrolling Interest [Abstract]
Balance, beginning of period	1,071	969	847	1,209
Balance, end of period	1,011	1,076	1,011	1,076
Foreign Currency Translation
AOCI Including Portion Attributable to Noncontrolling Interest [Abstract]
Balance, beginning of period	1,056	941	789	1,199
Other comprehensive (income) loss	(86)	139	181	(119)
Balance, end of period	970	1,080	970	1,080
Cash Flow Hedges
AOCI Including Portion Attributable to Noncontrolling Interest [Abstract]
Balance, beginning of period	13	25	16	21
Other comprehensive (income) loss	0	(7)	(3)	(3)
Balance, end of period	13	18	13	18
Defined Benefit Pension and Postretirement Plans
AOCI Including Portion Attributable to Noncontrolling Interest [Abstract]
Balance, beginning of period	753	754	793	740
Other comprehensive (income) loss	26	(25)	(14)	(11)
Balance, end of period	779	729	779	729
Other Reserves
AOCI Including Portion Attributable to Noncontrolling Interest [Abstract]
Balance, beginning of period	(751)	(751)	(751)	(751)
Other comprehensive (income) loss	0	0	0	0
Balance, end of period	$ (751)	$ (751)	$ (751)	$ (751)

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Loss - Schedule of Amounts Recognized in Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Foreign currency translation gain (loss), pre-tax	$ 86	$ (139)	$ (181)	$ 119
Foreign currency translation gain (loss), tax	0	0	0	0
Foreign currency translation gain (loss), net of tax	86	(139)	(181)	119
Defined benefit pension and other postretirement benefit plans adjustments:
Net actuarial loss arising during period, pre-tax			(1)	0
Net actuarial loss arising during period, tax			0	0
Net actuarial loss arising during period, net of tax			(1)	0
Amortization and settlement recognition of net actuarial loss, pre-tax	9	7	48	23
Amortization and settlement recognition of net actuarial loss, tax	(1)	(2)	(12)	(6)
Amortization and settlement recognition of net actuarial loss, net of tax	8	5	36	17
Amortization of prior service credit, pre-tax	(1)	(1)	(1)	(1)
Amortization of prior service credit, tax	0	0	0	0
Amortization of prior service credit, net of tax	(1)	(1)	(1)	(1)
Foreign currency (loss) gain - pensions, pre-tax	(33)	21	(20)	(5)
Foreign currency (loss) gain - pensions, tax	0	0	0	0
Foreign currency (loss) gain - pensions, net of tax	(33)	21	(20)	(5)
Derivatives:
Deferred gain recognized on cash flow hedges, pre-tax	0	7	3	3
Deferred gain recognized on cash flow hedges, tax	0	0	0	0
Deferred gain recognized on cash flow hedges, net of tax	0	7	3	3
Other comprehensive income (loss), pre-tax	61	(105)	(152)	139
Other Comprehensive Income (Loss), Tax, Total	1	2	12	6
Other comprehensive income (loss), net of tax	60	(107)	(164)	133
Other comprehensive income (loss) attributable to noncontrolling interests, pre-tax	0	0	0	0
Other comprehensive income (loss) attributable to noncontrolling interests, tax	0	0	0	0
Other comprehensive income (loss) attributable to noncontrolling interests, net of tax	0	0	0	0
Other comprehensive income (loss) attributable to common stockholders, pre-tax	61	(105)	(152)	139
Other comprehensive income (loss) attributable to common stockholders, tax	(1)	(2)	(12)	(6)
Other comprehensive income (loss) attributable to common stockholders, net of tax	$ 60	$ (107)	$ (164)	$ 133