Automatic Data Processing (ADP) 424B2Prospectus for primary offering

Filed Pursuant to Rule 424(b)(2)
Registration No. 333-281920

Prospectus Supplement

(To Prospectus Dated September 4, 2024)

$1,000,000,000

Automatic Data Processing, Inc.

$1,000,000,000 4.450% Senior Notes due 2034

We are offering $1,000,000,000 of our 4.450% Senior Notes due 2034 (the “Notes”). We will pay interest on the Notes on March 9 and September 9 of each year, beginning on March 9, 2025. The Notes will mature on September 9, 2034. At our option, we may redeem the Notes offered hereby in whole or in part at any time and from time to time before their maturity date at the redemption prices described herein under “Description of Notes—Optional Redemption.”

Upon a Change of Control Triggering Event, we will be required to make an offer to repurchase all outstanding Notes at a price in cash equal to 101% of the principal amount of the Notes, plus any accrued and unpaid interest to, but not including, the repurchase date.

The Notes will be our direct, senior unsecured obligations and will rank equally with all of our other direct, senior unsecured indebtedness from time to time outstanding.

Investing in the Notes involves risks. See the sections entitled “Risk Factors” beginning on page S-6 of this prospectus supplement and in our Annual Report on Form 10-K for the year ended June 30, 2024, which is incorporated by reference into this prospectus supplement and the accompanying prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus supplement or the accompanying prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The Notes will be ready for delivery in book-entry form only through the facilities of The Depository Trust Company for the accounts of its participants, including Euroclear Bank S.A./N.V. and Clearstream Banking, société anonyme, on or about September 9, 2024.

Joint Book-Running Managers

Co-Managers

September 4, 2024

We have not authorized anyone to provide any information other than that contained or incorporated by reference in this prospectus supplement, the accompanying prospectus or in any free writing prospectus prepared by or on behalf of us or to which we have referred you. We take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. This prospectus supplement and the accompanying prospectus are an offer to sell only the Notes, but only under circumstances and in jurisdictions where it is lawful to do so. The information contained in this prospectus supplement, the accompanying prospectus or in any free writing prospectus, as well as information previously filed with the Securities and Exchange Commission (“SEC”) and incorporated herein by reference, is current only as of the date of such information. Our business, financial condition, results of operations and prospects may have changed since that date.

References in this prospectus supplement and the accompanying prospectus to the “Company,” “ADP,” “we,” “us,” and “our” refer to Automatic Data Processing, Inc. and its subsidiaries, except where the context otherwise requires.

TABLE OF CONTENTS

Prospectus Supplement

Prospectus

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INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

The SEC allows ADP to “incorporate by reference” the information it files with the SEC. This permits ADP to disclose important information to you by referencing these filed documents, which are considered part of this prospectus supplement and the accompanying prospectus. Information that ADP files later with the SEC will automatically update and supersede this information.

We incorporate by reference the documents set forth below that ADP previously filed with the SEC and any future filings made with the SEC under Section 13(a), 13(c), 14 or 15(d) of the Exchange Act until the offering of the Notes has been completed; provided that, unless otherwise stated, we will not incorporate by reference any filing that is “furnished” or deemed “furnished” to the SEC.

The following documents filed with the SEC are incorporated by reference into this prospectus supplement:

ADP will provide without charge, upon written or oral request, a copy of any or all of the documents which are incorporated by reference in this prospectus supplement and the accompanying prospectus, other than exhibits which are specifically incorporated by reference into those documents. Requests should be directed to Investor Relations, Automatic Data Processing, Inc., One ADP Boulevard, Roseland, New Jersey 07068, telephone number (973) 974-5858. The information found on our website is not a part of this prospectus supplement or the accompanying prospectus.

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SPECIAL NOTE ON FORWARD-LOOKING STATEMENTS

This prospectus supplement and the accompanying prospectus contain “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Statements that are not historical in nature and which may be identified by the use of words like “outlook,” “expects,” “assumes,” “projects,” “anticipates,” “estimates,” “we believe,” “could,” “is designed to” and other words of similar meaning, are forward-looking statements. These statements are based on management’s expectations and assumptions and depend upon or refer to future events or conditions and are subject to risks and uncertainties that may cause actual results to differ materially from those expressed. Forward-looking statements are subject to inherent risks and uncertainties. Factors that could cause actual results to differ materially from those contemplated by the forward-looking statements or that could contribute to such difference include:

The factors identified above are not exhaustive. ADP disclaims any obligation to update any forward-looking statements, whether as a result of new information, future events, or otherwise, except as required by law. These risks and uncertainties, along with the risk factors discussed under “Item 1A. Risk Factors” in ADP’s most recently filed Annual Report on Form 10-K and the risk factors under the caption “Risk Factors” in this prospectus supplement and the accompanying prospectus, should be considered in evaluating any forward-looking statements contained herein.

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RISK FACTORS

Investing in the Notes involves risks. Before making a decision to invest in the Notes, you should carefully consider the risks described under “Risk Factors” in Item 1A. of our Annual Report on Form 10-K for the fiscal year ended June 30, 2024, which is incorporated by reference into this prospectus supplement and the accompanying prospectus, as well as the risks set forth below. See “Where You Can Find More Information” in the accompanying prospectus.

The indenture governing the Notes does not contain financial covenants or meaningful restrictions on us or our subsidiaries.

Neither we nor any of our subsidiaries are restricted from incurring additional debt or other liabilities under the indenture. We may from time to time incur additional debt and other liabilities. In addition, we are not restricted from paying dividends or making distributions on our capital stock or purchasing or redeeming our capital stock under the indenture.

Active trading markets for the Notes may not develop.

The Notes constitute a new issue of securities, for which there is no existing market. We do not intend to apply for listing of the Notes on any securities exchange. We cannot assure you trading markets for the Notes will develop, or of the ability of holders of the Notes to sell their Notes or of the prices at which holders may be able to sell their Notes. The underwriters have advised us that they currently intend to make a market in the Notes. However, the underwriters are not obligated to do so, and any market-making with respect to the Notes may be discontinued at any time without notice. If no active trading markets develop, you may be unable to resell the Notes at any price or at their fair market value.

If trading markets do develop, changes in our ratings or the financial markets could adversely affect the market prices of the Notes.

The market prices of the Notes will depend on many factors, including, among others, the following:

The condition of the financial markets and prevailing interest rates have fluctuated in the past and are likely to fluctuate in the future, which could have an adverse effect on the market prices of the Notes. In addition, rating agencies continually review the ratings they have assigned to companies and debt securities, including our company. Negative changes in the ratings assigned to us or our debt securities could have an adverse effect on the market prices of the Notes.

The Notes will be effectively subordinated to the indebtedness and other liabilities of our subsidiaries.

A significant portion of our operations are conducted through our subsidiaries. None of our subsidiaries is a guarantor of the Notes. As a result, our right to receive assets upon the liquidation or recapitalization of any of our subsidiaries, and your consequent right to benefit from our receipt of those assets, will be subject to the claims of such subsidiary’s creditors. Accordingly, the Notes are effectively subordinated to all indebtedness and other liabilities, including trade payables, of our subsidiaries. Even if we were recognized as a creditor of one or more of our subsidiaries, our claims would still be effectively subordinated to any security interests in or other liens on the assets of any such subsidiary and to any indebtedness or other liabilities of any such subsidiary senior to our claims. As of June 30, 2024, debt of our subsidiaries, to which the Notes will be structurally subordinated, was approximately $389.5 million.

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In addition, we derive a significant portion of our revenues from our subsidiaries. As a result, our cash flow and our ability to service our debt and other obligations, including the Notes, will depend on the results of operations of our subsidiaries and upon the ability of our subsidiaries to provide us with cash to pay amounts due on our obligations, including the Notes. Our subsidiaries are separate and distinct legal entities and have no obligation to make payments on the Notes or to make funds available to us for that purpose. In addition, dividends, loans or other distributions from our subsidiaries to us are dependent upon results of operations of our subsidiaries, may be subject to contractual and other restrictions, may be subject to tax or other laws limiting our ability to repatriate funds from foreign subsidiaries and may be subject to other business considerations.

The Notes will be unsecured and therefore will be effectively subordinated to any secured indebtedness we may incur.

The Notes will not be secured by any of our assets. As a result, the Notes will be effectively subordinated to any secured debt we or our subsidiaries may incur to the extent of the value of the assets securing such debt. In any liquidation, dissolution, bankruptcy or other similar proceeding, the holders of any of our secured debt and the secured debt of our subsidiaries may assert rights against the assets pledged to secure that debt in order to receive full payment of their debt before the assets may be used to pay other creditors, including the holders of the Notes. As of June 30, 2024, we had no secured indebtedness outstanding, not including the debt of our subsidiaries.

We may not be able to repurchase the Notes upon a Change of Control Triggering Event.

If a Change of Control Triggering Event occurs, we will be required to make an offer to repurchase all outstanding Notes at a price in cash equal to 101% of the principal amount of the Notes, plus any accrued and unpaid interest to, but not including, the repurchase date. We may not be able to repurchase the Notes upon a Change of Control Triggering Event, however, because we may not have sufficient funds to do so. In addition, agreements governing indebtedness we may incur in the future may restrict us from purchasing the Notes in the event of a Change of Control Triggering Event. Our failure to repurchase properly tendered Notes would constitute an event of default under the indenture governing the Notes. See “Description of Notes—Change of Control Offer.”

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USE OF PROCEEDS

We will receive net proceeds from the offering of the Notes of approximately $976.3 million after deducting underwriting discounts, commissions, costs related to interest rate hedges and estimated offering expenses. We intend to use the net proceeds of this offering for general corporate purposes.

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CAPITALIZATION

The following table sets forth a summary of our capitalization on a consolidated basis as of June 30, 2024. We have presented our capitalization on both an actual and an as adjusted basis to reflect the issuance and sale of the Notes offered hereby, but not the application of the net proceeds from the issuance and sale of the Notes. See “Use of Proceeds.” This table should be read in conjunction with our consolidated financial statements and the related notes incorporated by reference in this prospectus supplement and the accompanying prospectus.

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DESCRIPTION OF NOTES

This description of the Notes being offered hereby supplements and, to the extent it is inconsistent, replaces, the description of the general provisions of the debt securities and the indenture in the accompanying prospectus. The Notes will be senior debt issued under an indenture dated as of August 13, 2020, between Automatic Data Processing, Inc. and U.S. Bank Trust Company, National Association (as successor in interest to U.S. Bank National Association), as trustee, as supplemented by the third supplemental indenture to be dated as of September 9, 2024 (collectively, the “indenture”).

The following statements relating to the Notes and the indenture are summaries of certain provisions thereof and are subject to, and qualified in their entirety by reference to, the detailed provisions of the form of the Notes, the indenture and any supplemental indenture, officer’s certificate or similar document related to the Notes. Certain provisions of the indenture are summarized in the accompanying prospectus. We encourage you to read the summaries of the Notes and the indenture in both this prospectus supplement and the accompanying prospectus, as well as the form of the Notes and the indenture and any supplemental indenture, officer’s certificate or similar document related to the Notes.

General Terms of Notes

Interest and principal will be payable in U.S. dollars. The Notes will be issued only in minimum denominations of $2,000 and integral multiples of $1,000 in excess thereof. There will be no sinking fund payments for the Notes. We do not intend to apply for the listing of the Notes on a national securities exchange or for quotation of the Notes on any automated dealer quotation system.

The security registrar and transfer agent for the Notes will be U.S. Bank National Association until such time as a successor security registrar or transfer agent is appointed.

We may, without the consent of the noteholders, issue additional Notes having the same ranking and the same interest rate, maturity and other terms as the Notes offered by this prospectus supplement (except for the issue date, the public offering price, the payment of interest accruing prior to the issue date of such additional Notes and the first payment of interest following such issue date). Any such additional Notes will have the same terms as the Notes, provided that, if any additional Notes subsequently issued are not fungible for U.S. federal income tax purposes with any Notes previously issued, such additional Notes shall trade under a separate CUSIP number.

Interest

The Notes will be initially limited to $1,000,000,000 aggregate principal amount. The Notes will bear interest at 4.450% per year. Interest will be payable semi-annually in arrears on March 9 and September 9 of each year, beginning on March 9, 2025. Interest on the Notes will accrue from September 9, 2024, or from the most recent date to which interest has been paid or provided for.

Interest on the Notes will be paid to holders of record on the February 22 or August 25 immediately preceding the interest payment date. Interest on the Notes will be computed on the basis of a 360-day year of twelve 30-day months.

If an interest payment date for the Notes falls on a day that is not a business day, the interest payment shall be postponed to the next succeeding business day, and no interest on such payment shall accrue for the period from and after such interest payment date. It will be an event of default under the indenture if we fail to pay interest when due and such failure continues for 30 days.

The Notes will mature on September 9, 2034. If the maturity date for the Notes falls on a day that is not a business day, the principal of and interest on the Notes shall be due on the next succeeding business day, and no interest on such payment shall accrue for the period from and after the maturity date of the Notes.

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Ranking

The Notes will be direct, senior unsecured obligations of Automatic Data Processing, Inc. and will rank equally with all of our other direct, senior unsecured indebtedness from time to time outstanding. However, the Notes will be structurally subordinated to any indebtedness of our subsidiaries and will be effectively subordinated to any secured indebtedness to the extent of the value of the assets securing such indebtedness. As of June 30, 2024, we had $3,000.0 million of outstanding direct, senior unsecured indebtedness and no secured indebtedness, not including the debt of our subsidiaries. As of June 30, 2024, debt of our subsidiaries, to which the Notes will be structurally subordinated, was approximately $389.5 million.

Optional Redemption

Prior to June 9, 2034 (three months prior to the maturity date of the Notes) (the “Par Call Date”), we may redeem the Notes at our option, in whole or in part, at any time and from time to time, at a redemption price (expressed as a percentage of principal amount and rounded to three decimal places) equal to the greater of:

plus, in either case, accrued and unpaid interest on the principal amount being redeemed to, but excluding, the redemption date.

On or after the Par Call Date, we may redeem the Notes at our option, in whole or in part, at any time and from time to time, at a redemption price equal to 100% of the principal amount of the Notes being redeemed plus accrued and unpaid interest on the principal amount being redeemed to, but excluding, the redemption date.

“Treasury Rate” means, with respect to any redemption date, the yield determined by us in accordance with the following two paragraphs.

The Treasury Rate shall be determined by us after 4:15 p.m., New York City time (or after such time as yields on U.S. government securities are posted daily by the Board of Governors of the Federal Reserve System), on the third business day preceding the redemption date based upon the yield or yields for the most recent day that appear after such time on such day in the most recent statistical release published by the Board of Governors of the Federal Reserve System designated as “Selected Interest Rates (Daily)—H.15” (or any successor designation or publication) (“H.15”) under the caption “U.S. government securities—Treasury constant maturities—Nominal” (or any successor caption or heading) (“H.15 TCM”). In determining the Treasury Rate, we shall select, as applicable: (1) the yield for the Treasury constant maturity on H.15 exactly equal to the period from the redemption date to the Par Call Date (the “Remaining Life”); or (2) if there is no such Treasury constant maturity on H.15 exactly equal to the Remaining Life, the two yields—one yield corresponding to the Treasury constant maturity on H.15 immediately shorter than and one yield corresponding to the Treasury constant maturity on H.15 immediately longer than the Remaining Life—and shall interpolate to the Par Call Date on a straight-line basis (using the actual number of days) using such yields and rounding the result to three decimal places; or (3) if there is no such Treasury constant maturity on H.15 shorter than or longer than the Remaining Life, the yield for the single Treasury constant maturity on H.15 closest to the Remaining Life. For purposes of this paragraph, the applicable Treasury constant maturity or maturities on H.15 shall be deemed to have a maturity date equal to the relevant number of months or years, as applicable, of such Treasury constant maturity from the redemption date.

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If on the third business day preceding the redemption date H.15 TCM or any successor designation or publication is no longer published, we shall calculate the Treasury Rate based on the rate per annum equal to the semi-annual equivalent yield to maturity at 11:00 a.m., New York City time, on the second business day preceding such redemption date of the United States Treasury security maturing on, or with a maturity that is closest to, the Par Call Date, as applicable. If there is no United States Treasury security maturing on the Par Call Date but there are two or more United States Treasury securities with a maturity date equally distant from the Par Call Date, one with a maturity date preceding the Par Call Date and one with a maturity date following the Par Call Date, we shall select the United States Treasury security with a maturity date preceding the Par Call Date. If there are two or more United States Treasury securities maturing on the Par Call Date or two or more United States Treasury securities meeting the criteria of the preceding sentence, we shall select from among these two or more United States Treasury securities the United States Treasury security that is trading closest to par based upon the average of the bid and asked prices for such United States Treasury securities at 11:00 a.m., New York City time. In determining the Treasury Rate in accordance with the terms of this paragraph, the semi-annual yield to maturity of the applicable United States Treasury security shall be based upon the average of the bid and asked prices (expressed as a percentage of principal amount) at 11:00 a.m., New York City time, of such United States Treasury security, and rounded to three decimal places.

Our actions and determinations in determining the redemption price shall be conclusive and binding for all purposes, absent manifest error.

The Treasury Rate will be calculated on the third business day preceding the redemption date (or date of deposit in the case of a satisfaction and discharge). As used in this “Optional Redemption” section, the term “business day” means any day that is not a Saturday, Sunday or other day on which commercial banks in New York City are authorized or required by law to remain closed. The Trustee will not be responsible for such calculation nor shall the Trustee have any duty to monitor the accuracy of any calculations made by the Company.

Notice of any redemption will be electronically delivered or mailed at least 15 but not more than 60 days before the redemption date to each holder of record of the Notes to be redeemed at its registered address. The notice of redemption for the Notes will state, among other things, the amount of Notes to be redeemed, the redemption date, the CUSIP and ISIN number(s), the manner in which the applicable redemption price will be calculated and the place or places where payment will be made upon presentation and surrender of Notes to be redeemed. If less than all of the Notes are to be redeemed at our option, the trustee will select by lot or in such other manner in accordance with the customary procedures of the depositary, the Notes, or portions of the Notes, to be redeemed. Unless we default in the payment of the redemption price, interest will cease to accrue on any Notes that have been called for redemption at the redemption date.

ADP will not be required (i) to issue, register the transfer of or exchange any Notes during the period beginning at the opening of business 15 days before the day of the mailing of a notice of redemption of Notes selected for redemption and ending at the close of business on the day of such mailing, or (ii) to register the transfer of or exchange any Notes so selected for redemption in whole or in part, except the unredeemed portion of any such Notes being redeemed in part.

Limitation on Liens

Neither we nor any of our domestic wholly owned subsidiaries will create or incur any mortgage, pledge, security interest or lien (each, a “Lien”) on any Principal Property, whether now owned or hereafter acquired, in order to secure any Indebtedness, without effectively providing that the Notes shall be secured by a lien ranking equal to and ratably with (or, at our option, senior to) such secured Indebtedness until such time as such Indebtedness is no longer secured by such Lien, except:

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Notwithstanding the foregoing, we or any of our subsidiaries may, without equally and ratably securing the Notes, create or incur Liens which would otherwise be subject to the restrictions set forth in the preceding paragraph, if after giving effect thereto, Aggregate Debt does not exceed 20% of our Consolidated Net Worth on a consolidated basis calculated as of the date of the creation or incurrence of the Lien.

Certain Definitions

As used in this section, the following terms have the meanings set forth below.

“Aggregate Debt” means, as of the date of determination, the aggregate principal amount of our and our domestic wholly owned subsidiaries’ Indebtedness incurred after the closing date of the offering of the Notes and secured by Liens not permitted by the first paragraph under “—Limitation on Liens” above.

“Consolidated Net Worth” means, as of any date of determination, shareholders’ equity as reflected on our most recent consolidated balance sheet prepared in accordance with GAAP.

“GAAP” means accounting principles generally accepted in the United States of America, which are in effect as of the date of application thereof.

“Indebtedness” of any specified Person means any indebtedness in respect of borrowed money. “Person” means any individual, corporation, partnership, joint venture, association, limited liability company, joint- stock company, trust, unincorporated organization or government or any agency or political subdivision thereof.

“Principal Property” means our (1) principal offices in Roseland, New Jersey, or any replacement thereof and (2) each of our domestic processing/print center buildings, other operational offices and sales offices unless, with respect to clause (2), our board of directors (which term, as defined in the indenture, includes committees thereof) has determined in good faith that such center or office is not of material importance to the total business conducted by us and our wholly owned subsidiaries, taken as a whole.

Change of Control Offer

If a Change of Control Triggering Event occurs, unless we have exercised our option to redeem the Notes by notifying the noteholders to that effect as described above, we will be required to make an offer (a “Change of Control Offer”) to each holder of Notes to repurchase all or any part (equal to $2,000 or integral multiples of $1,000 in excess of $2,000) of that holder’s Notes. In a Change of Control Offer, we will be required to offer payment in cash equal to 101% of the aggregate principal amount of the Notes repurchased, plus accrued and unpaid interest, if any, on the Notes repurchased to, but excluding the date of repurchase (a “Change of Control Payment”). Within 30 days following any Change of Control Triggering Event or, at our option, prior to any Change of Control, but after public announcement of the transaction that constitutes or may constitute the Change of Control, a notice will be mailed to holders of the Notes, with a copy to the trustee, describing the transaction that constitutes or may constitute the Change of Control Triggering Event and offering to repurchase the Notes on the date specified in the notice, which date will be no earlier than 30 days and no later than 60 days

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from the date that notice is mailed, other than as may be required by law (a “Change of Control Payment Date”). The notice will, if mailed prior to the date of consummation of the Change of Control, state that the Change of Control Offer is conditioned on the Change of Control Triggering Event occurring on or prior to the applicable Change of Control Payment Date.

On each Change of Control Payment Date, we will, to the extent lawful:

We will not be required to make a Change of Control Offer upon the occurrence of a Change of Control Triggering Event if a third party makes such an offer in the manner, at the times and otherwise in compliance with the requirements for an offer made by us and the third party repurchases all Notes properly tendered and not withdrawn under its offer.

To the extent that we are required to offer to repurchase the Notes upon the occurrence of a Change of Control Triggering Event, we may not have sufficient funds to repurchase the Notes in cash at such time. In addition, our ability to repurchase the Notes for cash may be limited by law or the terms of other agreements relating to our indebtedness outstanding at the time. The failure to make such repurchase would result in a default under the Notes.

We will comply with the requirements of Rule 14e-1 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”) and any other securities laws and regulations thereunder to the extent those laws and regulations are applicable in connection with the repurchase of the Notes as a result of a Change of Control Triggering Event. To the extent that the provisions of any such securities laws or regulations conflict with the Change of Control Offer provisions of the Notes, we will comply with those securities laws and regulations and will not be deemed to have breached our obligations under the Change of Control Offer provisions of the Notes by virtue of any such conflict.

For purposes of the Change of Control Offer provisions of the Notes, the following terms will be applicable:

“Change of Control” means the occurrence of any of the following: (1) the direct or indirect sale, lease, transfer, conveyance or other disposition (other than by way of merger or consolidation), in one or a series of related transactions, of all or substantially all of our assets and the assets of our subsidiaries, taken as a whole, to any person, other than our company or one of our subsidiaries; (2) the consummation of any transaction (including, without limitation, any merger or consolidation) the result of which is that any person becomes the beneficial owner (as defined in Rules 13d-3 and 13d-5 under the Exchange Act), directly or indirectly, of more than 50% of our outstanding Voting Stock or other Voting Stock into which our Voting Stock is reclassified, consolidated, exchanged or changed, measured by voting power rather than number of shares; (3) we consolidate with, or merge with or into, any person, or any person consolidates with, or merges with or into, us, in any such event pursuant to a transaction in which any of our outstanding Voting Stock or the Voting Stock of such other person is converted into or exchanged for cash, securities or other property, other than any such transaction where the shares of our Voting Stock outstanding immediately prior to such transaction constitute, or are converted into or exchanged for, a majority of the Voting Stock of the surviving person or any direct or indirect parent company of the surviving person immediately after giving effect to such transaction; or (4) the adoption of

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a plan relating to our liquidation or dissolution. Notwithstanding the foregoing, a transaction will not be deemed to involve a Change of Control under clause (2) above if (i) we become a direct or indirect wholly-owned subsidiary of a holding company and (ii)(A) the direct or indirect holders of the Voting Stock of such holding company immediately following that transaction are substantially the same as the holders of our Voting Stock immediately prior to that transaction or (B) the shares of our Voting Stock outstanding immediately prior to such transaction are converted into or exchanged for, a majority of the Voting Stock of such holding company immediately after giving effect to such transaction. The term “person,” as used in this definition, has the meaning given thereto in Section 13(d)(3) of the Exchange Act.

The definition of “change of control” includes a phrase relating to the direct or indirect sale, lease, transfer, conveyance or other disposition of “all or substantially all” of our assets and the assets of our subsidiaries, taken as a whole. Although there is a limited body of case law interpreting the phrase “substantially all,” there is no precise established definition of the phrase under applicable law. Accordingly, the ability of a holder of Notes to require us to repurchase its Notes as a result of a sale, lease, transfer, conveyance or other disposition of less than all of our assets and the assets of our subsidiaries, taken as a whole, to another person or group may be uncertain.

“Change of Control Triggering Event” means the occurrence of both a Change of Control and a Rating Event.

“Fitch” means Fitch Ratings Inc. and its successors.

“Investment Grade Rating” means a rating equal to or higher than Baa3 (or the equivalent) by Moody’s, BBB- (or the equivalent) by S&P and BBB- (or the equivalent) by Fitch, and the equivalent investment grade credit rating from any replacement rating agency or rating agencies selected by us.

“Moody’s” means Moody’s Investors Service, Inc. and its successors.

“Rating Agencies” means (1) each of Moody’s, S&P and Fitch; and (2) if any or all of Moody’s, S&P or Fitch ceases to rate the applicable Notes or fails to make a rating of the applicable Notes publicly available for reasons beyond our control, a “nationally recognized statistical rating organization” within the meaning of Rule 15c3-1(c)(2)(vi)(F) under the Exchange Act selected by us (as certified by a resolution of our Board of Directors) as a replacement agency for Moody’s, S&P or Fitch, or all of them, as the case may be.

“Rating Event” means the rating on the Notes is lowered by at least two of the three Rating Agencies and the Notes are rated below an Investment Grade Rating by at least two of the three Rating Agencies, in any case on any day during the period (which period will be extended so long as the rating of the Notes is under publicly announced consideration for a possible downgrade by any of the Rating Agencies) commencing 60 days prior to the earlier of (i) the first public notice of the occurrence of a Change of Control or (ii) the first public notice of our intention to effect a Change of Control and ending 60 days following consummation of such Change of Control.

“S&P” means Standard & Poor’s Rating Services, a division of S&P Global Inc., and its successors.

“Voting Stock” means, with respect to any specified “person” (as that term is used in Section 13(d)(3) of the Exchange Act) as of any date, the capital stock of that person that is at the time entitled to vote generally in the election of the board of directors of that person.

Global Clearance and Settlement Procedures

Investors in the global securities representing the Notes (the “Global Notes”) may hold a beneficial interest in such Global Notes through DTC, Clearstream Banking, société anonyme (“Clearstream”) or the Euroclear System (“Euroclear”) or through participants. The Notes may be traded as home market instruments in both the European and U.S. domestic markets. Initial settlement and all secondary trades will settle as set forth below.

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Clearstream has advised that it is incorporated under the laws of the Grand Duchy of Luxembourg as a professional depositary. Clearstream holds securities for its participating organizations (“Clearstream Participants”). Clearstream facilitates the clearance and settlement of securities transactions between Clearstream Participants through electronic book-entry changes in accounts of Clearstream Participants, eliminating the need for physical movement of certificates. Clearstream provides to Clearstream Participants, among other things, services for safekeeping, administration, clearance and settlement of internationally traded securities and securities lending and borrowing. Clearstream interfaces with domestic markets in several countries. As a professional depositary, Clearstream is subject to regulation by the Luxembourg Commission for the Supervision of the Financial Sector (CSSF). Clearstream Participants are recognized financial institutions around the world, including underwriters, securities brokers and dealers, banks, trust companies, clearing corporations and certain other organizations. Indirect access to Clearstream is also available to others, such as banks, brokers, dealers and trust companies that clear through or maintain a custodial relationship with a Clearstream Participant, either directly or indirectly.

Distributions, to the extent received by the U.S. Depositary (as defined below) for Clearstream, with respect to the Notes held beneficially through Clearstream will be credited to cash accounts of Clearstream Participants in accordance with its rules and procedures.

Euroclear has advised that it was created in 1968 to hold securities for its participants (“Euroclear Participants”) and to clear and settle transactions between Euroclear Participants through simultaneous electronic book-entry delivery against payment, eliminating the need for physical movement of certificates and eliminating any risk from lack of simultaneous transfers of securities and cash. Euroclear provides various other services, including securities lending and borrowing and interfaces with domestic markets in several countries. Euroclear is operated by Euroclear Bank S.A./ N.V. (the “Euroclear Operator”), under contract with Euroclear Clearance Systems S.C., a Belgian cooperative corporation (the “Cooperative”). All operations are conducted by the Euroclear Operator, and all Euroclear securities clearance accounts and Euroclear cash accounts are accounts with the Euroclear Operator not the Cooperative. The Cooperative establishes policy for Euroclear on behalf of Euroclear Participants. Euroclear Participants include banks (including central banks), securities brokers and dealers and other professional financial intermediaries and may include the underwriters. Indirect access to Euroclear is also available to other firms that clear through or maintain a custodial relationship with a Euroclear Participant, either directly or indirectly.

The Euroclear Operator has advised us that it is licensed by the Belgian Banking and Finance Commission to carry out banking activities on a global basis. As a Belgian bank, it is regulated and examined by the Belgian Banking and Finance Commission.

Securities clearance accounts and cash accounts with the Euroclear Operator are governed by the Terms and Conditions Governing Use of Euroclear and the related Operating Procedures of the Euroclear System, and applicable Belgian law (collectively, the “Terms and Conditions”). The Terms and Conditions govern transfers of securities and cash within Euroclear, withdrawals of securities and cash from Euroclear, and receipts of payments with respect to securities in Euroclear. All securities in Euroclear are held on a fungible basis without attribution of specific certificates to specific securities clearance accounts. The Euroclear Operator acts under the Terms and Conditions only on behalf of Euroclear Participants and has no record of or relationship with persons holding through Euroclear Participants.

Distributions, to the extent received by the U.S. Depositary for Euroclear, with respect to Notes held beneficially through Euroclear will be credited to the cash accounts of Euroclear Participants in accordance with the Terms and Conditions.

Individual certificates in respect of Notes will not be issued in exchange for the Global Notes, except in very limited circumstances, including under the following circumstances. If DTC notifies us that it is unwilling or unable to continue as a clearing system in connection with a Global Note or DTC ceases to be a clearing agency

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registered under the Exchange Act, and in each case we do not appoint a successor clearing system within 90 days after receiving such notice from Euroclear, Clearstream or DTC or on becoming aware that DTC is no longer so registered, we will issue or cause to be issued individual certificates in registered form on registration of transfer of or in exchange for book-entry interests in the Notes represented by such Global Note upon delivery of such Global Note for cancellation.

Title to book-entry interests in the Notes will pass by book-entry registration of the transfer within the records of Euroclear, Clearstream or DTC, as the case may be, in accordance with their respective procedures. Book-entry interests in the Notes may be transferred within Euroclear and within Clearstream and between Euroclear and Clearstream in accordance with procedures established for these purposes by Euroclear and Clearstream. Book-entry interests in the Notes may be transferred within DTC in accordance with procedures established for this purpose by DTC. Transfers of book-entry interests in the Notes between Euroclear and Clearstream and DTC may be effected in accordance with procedures established for this purpose by Euroclear, Clearstream and DTC.

Initial Settlement

All Global Notes will be registered in the name of Cede & Co. as nominee of DTC. Investors’ interests in the Global Notes will be represented through financial institutions acting on their behalf as direct and indirect participants in DTC. As a result, Clearstream and Euroclear will hold positions on behalf of their participants through their respective U.S. depositaries (each, a “U.S. Depositary”), which in turn will hold such positions in accounts as participants of DTC.

Notes held through DTC will be settled in immediately available funds. Investor securities custody accounts will be credited with their holdings against payment on the settlement date. Notes held through Clearstream or Euroclear accounts will follow the settlement procedures applicable to conventional eurobonds, except that there will be no temporary global security and no “lock-up” or restricted period. Notes will be credited to the securities custody accounts on the settlement date against payment.

Secondary Market Trading

Since the purchaser determines the place of delivery, it is important to establish at the time of the trade where both the purchaser’s and seller’s accounts are located to ensure that settlement can be made on the desired value date.

Trading between DTC Participants

Secondary market trading between DTC participants will be settled in immediately available funds.

Trading between Clearstream and/or Euroclear Participants

Secondary market trading between Clearstream participants and/or Euroclear participants will be settled using the procedures applicable to conventional eurobonds.

Trading between DTC Seller and Clearstream or Euroclear Purchaser

When beneficial interests in the Global Notes are to be transferred from the account of a DTC participant to the account of a Clearstream participant or a Euroclear participant, the purchaser will send instructions to Clearstream or Euroclear through a participant at least one business day prior to settlement. Clearstream or Euroclear will instruct the U.S. Depositary to receive a beneficial interest in the Global Notes against payment. Unless otherwise set forth in this prospectus supplement, payment will include interest accrued on the beneficial interest in the Global Notes of a series so transferred from and including the last interest payment date to and

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excluding the settlement date, on the basis on which interest is calculated on the Notes. For transactions settling on the 31st of the month, payment will include interest accrued to and excluding the first day of the following month. Payment will then be made by the U.S. Depositary to the DTC participant’s account against delivery of the beneficial interest in the Global Notes. After settlement has been completed, the beneficial interest in the Global Notes will be credited to the respective clearing system and by the clearing system, in accordance with its usual procedures, to the Clearstream or Euroclear participant’s account. The securities credit will appear the next day (European time) and the cash debit will be back-valued to, and interest on the beneficial interest in the Global Notes will accrue from, the value date (which would be the preceding day when settlement occurred in New York). If settlement is not completed on the intended value date (that is, the trade fails), the Clearstream or Euroclear cash debit will be valued instead as of the actual settlement date.

Clearstream participants and Euroclear participants will need to make available to the respective clearing systems the funds necessary to process same-day funds settlement. The most direct means of doing so is to preposition funds for settlement, either from cash on hand or existing lines of credit, as they would for any settlement occurring within Clearstream or Euroclear. Under this approach, they may take on credit exposure to Clearstream or Euroclear until the beneficial interests in the Global Notes are credited to their accounts one day later.

As an alternative, if Clearstream or Euroclear has extended a line of credit to them, participants can elect not to preposition funds and allow that credit line to be drawn upon to finance settlement. Under this procedure, Clearstream participants or Euroclear participants purchasing a beneficial interest in the Global Notes would incur overdraft charges for one day, assuming they cleared the overdraft when the beneficial interests in the Global Notes were credited to their accounts. However, interest on the beneficial interests in the Global Notes would accrue from the value date. Therefore, in many cases the investment income on the Global Notes earned during that one-day period may substantially reduce or offset the amount of such overdraft charges, although this result will depend on each participant’s particular cost of funds.

Since the settlement is taking place during New York business hours, DTC participants can employ their usual procedures for sending a beneficial interest in the Global Notes to the U.S. Depositary for the benefit of Clearstream participants or Euroclear participants. The sale proceeds will be available to the DTC seller on the settlement date. Thus, to the DTC participant a cross-market transaction will settle no differently than a trade between two DTC participants.

Trading between Clearstream or Euroclear Seller and DTC Purchaser

Due to time zone differences in their favor, Clearstream and Euroclear participants may employ their customary procedures in transactions in which a beneficial interest in the Global Notes is to be transferred by the respective clearing system, through the U.S. Depositary, to a DTC participant. The seller will send instructions to Clearstream or Euroclear through a participant at least one business day prior to settlement. In these cases, Clearstream or Euroclear will instruct the U.S. Depositary to deliver the beneficial interest in the Global Notes to the DTC participant’s account against payment. Payment will include interest accrued on the beneficial interest in the Global Notes from and including the last coupon payment date to and excluding the settlement date on the basis on which interest is calculated on the Global Notes. For transactions settling on the 31st of the month, payment will include interest accrued to and excluding the first day of the following month. The payment will then be reflected in the account of the Clearstream or Euroclear participant the following day, and receipt of the cash proceeds in the Clearstream or Euroclear participant’s account would be back-valued to the value date (which would be the preceding day, when settlement occurred in New York). Should the Clearstream or Euroclear participant have a line of credit with its respective clearing system and elect to be in debit in anticipation of receipt of the sale proceeds in its account, the back-valuation will extinguish any overdraft charges incurred over that one-day period. If settlement is not completed on the intended value date (that is, the

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trade fails), receipt of the cash proceeds in the Clearstream or Euroclear participant’s account would instead be valued as of the actual settlement date.

Finally, day traders that use Clearstream or Euroclear and that purchase beneficial interests in the Global Notes from DTC participants for credit to Clearstream participants or Euroclear participants should note that these trades would automatically fail on the sale side unless affirmative action is taken. At least three techniques should be readily available to eliminate this potential problem:

Although DTC, Clearstream and Euroclear have agreed to the foregoing procedures in order to facilitate transfers of beneficial interests in the Global Notes among participants of DTC, Clearstream and Euroclear, they are under no obligation to perform or continue to perform such procedures and such procedures may be discontinued at any time.

Applicable Law

The Notes and the indenture will be governed by and construed in accordance with the laws of the State of New York.

Additional Terms

For additional important information about the Notes, see “Description of Debt Securities” in the accompanying prospectus. That information includes:

To the extent any information about the Notes varies between this prospectus supplement and the accompanying prospectus, you should rely on the information contained in this prospectus supplement.

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MATERIAL U.S. FEDERAL INCOME TAX CONSEQUENCES

The following are the material U.S. federal income tax consequences of owning and disposing of Notes that are purchased in this offering at the “issue price,” which is the first price at which a substantial amount of the Notes is sold to the public, and are held as capital assets for U.S. federal income tax purposes.

This discussion does not describe all of the tax consequences that may be relevant to you in light of your particular circumstances, including alternative minimum tax and Medicare contribution tax consequences, the application of Section 451 of the Code (as defined below) with respect to conforming the timing of income accruals to financial statements, as well as differing tax consequences that may apply if you are, for instance:

If you are a partnership for U.S. federal income tax purposes, the U.S. federal income tax treatment of your partners will generally depend on the status of the partners and your activities.

This summary is based on the Internal Revenue Code of 1986, as amended to the date hereof (the “Code”), administrative pronouncements, judicial decisions and final, temporary and proposed Treasury Regulations, changes to any of which subsequent to the date of this prospectus supplement may affect the tax consequences described herein, possibly on a retroactive basis. This summary does not address any aspect of state, local or non-U.S. taxation, or any taxes other than income taxes. You should consult your tax adviser with regard to the application of the U.S. federal tax laws to your particular situation, as well as any tax consequences arising under the laws of any state, local or foreign taxing jurisdiction.

Tax Consequences to U.S. Holders

This section applies to you if you are a U.S. Holder. You are a U.S. Holder if you are a beneficial owner of a Note that is, for U.S. federal income tax purposes:

Certain Additional Payments

There are circumstances in which we might be required to make payments on a Note that would increase the yield of the Note, as described under “Description of Notes—Change of Control Offer.” We intend to take the position that the possibility that any such payments will be made does not cause the Notes to be treated as contingent payment debt instruments under the applicable Treasury Regulations. Our position is not binding on

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the Internal Revenue Service (“IRS”). If the IRS takes a contrary position, you may be required to accrue interest income based upon a “comparable yield” (as defined in the Treasury Regulations) determined at the time of issuance of the Notes (which is not expected to differ significantly from the actual yield on the Notes), with adjustments to such accruals when any contingent payments are made that differ from the payments based on the comparable yield. In addition, any income on the sale, exchange, retirement or other taxable disposition of the Notes would be treated as interest income rather than as capital gain. You should consult your tax adviser regarding the tax consequences if the Notes were treated as contingent payment debt instruments. The remainder of this discussion assumes that the Notes are not treated as contingent payment debt instruments.

Payments of Interest

Stated interest on a Note will be taxable to you as ordinary interest income at the time it accrues or is received, in accordance with your method of accounting for U.S. federal income tax purposes.

Sale or Other Taxable Disposition of the Notes

Upon the sale or other taxable disposition of a Note, you will recognize taxable gain or loss equal to the difference between the amount realized on the sale or other taxable disposition and your adjusted tax basis in the Note. Your adjusted tax basis in a Note will equal the cost of your Note. For these purposes, the amount realized does not include any amount attributable to accrued interest, which is treated as described under “Payments of Interest” above.

Gain or loss realized on the sale or other taxable disposition of a Note will generally be capital gain or loss and will be long-term capital gain or loss if at the time of the sale or other taxable disposition the Note has been held for more than one year. Long-term capital gains recognized by non-corporate taxpayers are subject to reduced tax rates. The deductibility of capital losses is subject to limitations.

Tax Consequences to Non-U.S. Holders

This section applies to you if you are a Non-U.S. Holder. You are a Non-U.S. Holder if you are a beneficial owner of a Note that is, for U.S. federal income tax purposes:

You are not a Non-U.S. Holder if you are a nonresident alien individual present in the United States for 183 days or more in the taxable year of disposition of a Note, or if you are a former citizen or former resident of the United States, in either of which cases you should consult your tax adviser regarding the U.S. federal income tax consequences of owning or disposing of a Note.

Payments on the Notes

Subject to the discussion below under “Backup Withholding and Information Reporting” and “FATCA Legislation,” payments of principal and interest on the Notes by the Company or any paying agent to you will not be subject to U.S. federal income or withholding tax, provided that, in the case of interest,

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If you cannot satisfy one of the first three requirements described above and interest on the Notes is not exempt from withholding because it is effectively connected with your conduct of a trade or business in the United States as described below, payments of interest on the Notes will be subject to withholding tax at a rate of 30%, or the rate specified by an applicable treaty.

Sale or Other Taxable Disposition of the Notes

Subject to the discussion below under “Backup Withholding and Information Reporting” and “FATCA Legislation,” you generally will not be subject to U.S. federal income or withholding tax on gain realized on a sale or other taxable disposition of Notes, unless the gain is effectively connected with your conduct of a trade or business in the United States as described below, although any amounts attributable to accrued interest will be treated as described above under “Payments on the Notes.”

Effectively Connected Income

If interest or gain on a Note is effectively connected with your conduct of a trade or business in the United States (and, if required by an applicable income tax treaty, is attributable to a U.S. permanent establishment or fixed base maintained by you), you will generally be taxed on such interest or gain in the same manner as a U.S. Holder (see “Tax Consequences to U.S. Holders” above). In this case, you will be exempt from the withholding tax on interest discussed above, although you will be required to provide a properly executed IRS Form W-8ECI in order to claim an exemption from withholding. You should consult your tax adviser with respect to other U.S. tax consequences of the ownership and taxable disposition of Notes, including the possible imposition of a branch profits tax at a rate of 30% (or a lower treaty rate) if you are a corporation.

Backup Withholding and Information Reporting

If you are a U.S. Holder, information returns are required to be filed with the IRS in connection with payments on the Notes and proceeds received from a sale or other taxable disposition of the Notes unless you are an exempt recipient. You may also be subject to backup withholding on these payments in respect of your Notes unless you provide your taxpayer identification number and otherwise comply with applicable requirements of the backup withholding rules or you provide proof of an applicable exemption.

If you are a Non-U.S. Holder, information returns are required to be filed with the IRS in connection with payments of interest on the Notes. Unless you comply with certification procedures to establish that you are not a United States person, information returns may also be filed with the IRS in connection with the proceeds from a sale or other taxable disposition of a Note. You may be subject to backup withholding on payments on the Notes or on the proceeds from a sale or other taxable disposition of the Notes unless you comply with certification procedures to establish that you are not a United States person or otherwise establish an exemption. The certification procedures required to claim the exemption from withholding tax on interest described above will satisfy the certification requirements necessary to avoid backup withholding as well.

Amounts withheld under the backup withholding rules are not additional taxes and may be refunded or credited against your U.S. federal income tax liability, provided the required information is timely furnished to the IRS.

FATCA Legislation

Provisions commonly referred to as “FATCA” impose withholding of 30% on payments of interest on the Notes to “foreign financial institutions” (which is broadly defined for this purpose and in general includes

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investment vehicles) and certain other non-U.S. entities unless various U.S. information reporting and due diligence requirements (generally relating to ownership by U.S. persons of interests in or accounts with those entities) have been satisfied, or an exemption applies, which is typically evidenced by delivery of a properly executed IRS Form W-8BEN-E. An intergovernmental agreement between the United States and an applicable foreign country may modify these requirements. Although existing FATCA regulations would also impose withholding on payments of gross proceeds from the sale or other disposition (including a retirement or redemption) of the Notes, regulations proposed by the U.S. Treasury Department (the preamble to which indicates that taxpayers may rely on the proposed regulations pending their finalization) would eliminate the requirement under FATCA of withholding on gross proceeds (other than payments of interest) of the disposition of the Notes. If FATCA withholding is imposed, a beneficial owner that is not a foreign financial institution generally will be entitled to a refund of any amounts withheld by filing a U.S. federal income tax return (which may entail significant administrative burden). You should consult your tax adviser regarding the effects of FATCA on your investment in the Notes.

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CERTAIN BENEFIT PLAN INVESTOR CONSIDERATIONS

The following is a summary of certain considerations associated with the purchase and holding of the Notes, or any interest therein, by (i) employee benefit plans subject to Title I of the Employee Retirement Income Security Act of 1974, as amended (“ERISA”), (ii) plans described in Section 4975 of the Code which are subject to Section 4975 of the Code (including an individual retirement account (“IRA”) and a Keogh plan) or provisions under other U.S. or non-U.S. federal, state, local or other laws or regulations that are similar to the fiduciary responsibility or prohibited transaction provisions of Title I of ERISA or Section 4975 of the Code (collectively, “Similar Laws”), and (iii) entities, the underlying assets of which are considered to include “plan assets” (pursuant to regulations issued by the U.S. Department of Labor in 29 C.F.R. Section 2510.3-101, as modified by Section 3(42) of ERISA or otherwise) of any such plan, account or arrangement described in clauses (i) and (ii) (each of the foregoing described in clauses (i), (ii) and (iii) referred to herein as a “Plan”).

General Fiduciary Matters

ERISA and the Code impose certain duties on persons who are fiduciaries of a Plan subject to Title I of ERISA or Section 4975 of the Code (each, a “Covered Plan”) and prohibit certain transactions involving the assets of a Covered Plan and its fiduciaries or other interested parties. Under ERISA and the Code, any person who exercises discretionary authority or control over the administration of a Covered Plan or the management or disposition of the assets of a Covered Plan, or who renders investment advice for a fee or other compensation to a Covered Plan, is generally considered to be a fiduciary of the Covered Plan.

When considering an investment in the Notes, or any interest therein, with the assets of any Plan, a fiduciary should determine whether the investment is in accordance with the documents and instruments governing the Plan and the applicable provisions of ERISA, the Code or any Similar Laws relating to a fiduciary’s duties to the Plan including, without limitation, the prudence, diversification, delegation of control, conflicts of interest and prohibited transaction provisions of ERISA, the Code and any applicable Similar Laws.

Plan fiduciaries should consider the fact that none of the Company, the underwriters or any of their respective affiliates (collectively, the “Transaction Parties”) is acting, or will act, as a fiduciary to any Plan with respect to the decision to purchase and/or hold the Notes, or any interest therein, in connection with this offering. The Transaction Parties are not undertaking to provide impartial investment advice or advice based on any particular investment need, or to give advice in a fiduciary capacity, with respect to the decision to purchase and/or hold the Notes, or any interest therein, in connection with this offering.

Prohibited Transaction Issues

Section 406 of ERISA and Section 4975 of the Code prohibit Covered Plans from engaging in specified transactions involving plan assets with persons or entities who are “parties in interest,” within the meaning of Section 406 of ERISA, or “disqualified persons,” within the meaning of Section 4975 of the Code, unless an exemption is available. A party in interest or disqualified person who engages in a non-exempt prohibited transaction may be subject to excise taxes and other penalties and liabilities under ERISA and the Code and may result in the disqualification of an IRA if the prohibited transaction involves the IRA owner or his or her beneficiary. In addition, the fiduciary of a Plan that engages in such a non-exempt prohibited transaction may also be subject to penalties and liabilities under ERISA and/or the Code.

The acquisition and/or holding of Notes, or any interest therein, by a Covered Plan with respect to which a Transaction Party is considered a party in interest or a disqualified person may constitute or result in a direct or indirect prohibited transaction under Section 406 of ERISA and/or Section 4975 of the Code, unless the Notes, or any interest therein, are acquired and held in accordance with an applicable statutory, class or individual prohibited transaction exemption. Included among these statutory exemptions are Section 408(b)(17) of ERISA and Section 4975(d)(20) of the Code (the so-called “service provider exemption”), which exempt certain

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transactions (including, without limitation, a sale and purchase of securities) between a Covered Plan and a party in interest or disqualified person so long as (i) such party in interest or disqualified person is treated as such solely by reason of providing services to the Covered Plan, (ii) such party in interest or disqualified person is not a fiduciary which renders investment advice, or has or exercises discretionary authority or control, with respect to the plan assets involved in such transaction, or an affiliate of any such person and (iii) the Covered Plan neither receives less than nor pays more than “adequate consideration” (as defined in such sections of ERISA and the Code) in connection with such transaction. In addition, the U.S. Department of Labor has issued prohibited transaction class exemptions (“PTCEs”) that may apply to the acquisition and holding of the Notes by a Covered Plan. These class exemptions include, without limitation, PTCE 84-14, as amended, with respect to transactions determined by independent qualified professional asset managers, PTCE 90-1, with respect to insurance company pooled separate accounts, PTCE 91-38, with respect to bank collective investment funds, PTCE 95-60, with respect to life insurance company general accounts and PTCE 96-23, with respect to transactions determined by in-house asset managers. Each of the above-noted exemptions contains conditions and limitations on its application. Fiduciaries of Covered Plans considering acquiring and/or holding the Notes, or any interest therein, in reliance on these or any other exemptions should carefully review the exemption to assure it is applicable. There can be no assurance that any such exemptions will be available, or that all of the conditions of any such exemptions will be satisfied with respect to transactions involving the Notes, or any interest therein.

Government plans (as defined in Section 3(32) of ERISA), non-U.S. plans (as described in Section 4(b)(4) of ERISA) and certain church plans( as defined in Section 3(33) of ERISA or Section 4975(g)(3) of the Code), while not subject to the fiduciary responsibility provisions of Title I of ERISA or the prohibited transaction provisions of Section 406 of ERISA or Section 4975 of the Code, may nevertheless be subject to Similar Laws. Fiduciaries of such Plans should consult with their counsel regarding the potential consequences of an investment in the Notes, or any interest therein, under any applicable Similar Laws before acquiring the Notes.

Representations

Accordingly, by its acceptance of the Notes, or any interest therein, each purchaser and holder of the Notes, or any interest therein, and each subsequent transferee of the Notes, or any interest therein, will be deemed to have represented and warranted that either (i) such purchaser or subsequent transferee is not, and is not acting on behalf of or using the assets of, a Plan to acquire or hold the Notes, or any interest therein, or (ii) the purchase, holding and subsequent disposition of the Notes, or any interest therein, by such purchaser or transferee does not, and will not, constitute or result in a non-exempt prohibited transaction under Section 406 of ERISA or Section 4975 of the Code or a violation under any applicable Similar Laws.

The foregoing discussion is general in nature and is not intended to be all-inclusive. Due to the complexity of these rules and the penalties that may be imposed upon persons involved in non-exempt prohibited transactions, it is particularly important that fiduciaries or other persons considering purchasing and/or holding of the Notes, or any interest therein, on behalf of, or with the assets of, any Plan, consult with their counsel regarding the potential applicability of ERISA, Section 4975 of the Code or any Similar Law and whether an exemption would be required. Neither this discussion nor anything provided in this prospectus supplement is, or is intended to be, investment advice directed at any potential Plan purchasers, or at Plan purchasers generally, and such purchasers of the Notes, or any interest therein, should consult and rely on their own counsel and advisers as to whether an investment in the Notes, or any interest therein, is suitable for the Plan.

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UNDERWRITING

BofA Securities, Inc., J.P. Morgan Securities LLC and Morgan Stanley & Co. LLC are acting as representatives of the underwriters named below. Subject to the terms and conditions stated in the underwriting agreement dated the date of this prospectus supplement, each underwriter named below has agreed, severally and not jointly, to purchase, and we have agreed to sell to that underwriter, the principal amount of the Notes set forth opposite the underwriter’s name.

The underwriting agreement provides that the obligations of the underwriters to purchase the Notes included in this offering are subject to approval of legal matters by counsel and to other conditions. Subject to the terms and conditions set forth in the underwriting agreement, the underwriters have agreed, severally and not jointly, to purchase all of the notes sold under the underwriting agreement if any of these notes are purchased. If an underwriter defaults, the underwriting agreement provides that the purchase commitments of the non-defaulting underwriters may be increased or the underwriting agreement may be terminated.

Notes sold by the underwriters to the public will initially be offered at the initial public offering price set forth on the cover of this prospectus supplement. Any Notes sold by the underwriters to securities dealers may be sold at such initial public offering price less a concession not to exceed 0.25% of the principal amount of the Notes. The underwriters may allow, and such securities dealers may reallow, a concession not to exceed 0.20% of the principal amount of the Notes. If all the Notes are not sold at the initial offering price, the underwriters may change the offering price and the other selling terms.

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The following table shows the underwriting discounts that we are to pay to the underwriters in connection with this offering (expressed as a percentage of the principal amount of the Notes).

We estimate that our total expenses for this offering, including costs related to interest rate hedges, will be approximately $15.6 million.

In connection with the offering, the underwriters may purchase and sell the Notes in the open market.

Purchases and sales in the open market may include short sales, purchases to cover short positions and stabilizing purchases.

Purchases to cover short positions and stabilizing purchases, as well as other purchases by the underwriters for their own accounts, may have the effect of preventing or retarding a decline in the market price of the Notes.

They may also cause the price of the Notes to be higher than the price that would otherwise exist in the open market in the absence of these transactions. The underwriters may conduct these transactions in the over-the- counter market or otherwise. If the underwriters commence any of these transactions, they may discontinue them at any time.

The underwriters reserve the right to reject, cancel or modify any order for Notes in whole or in part.

Conflicts of Interest

The underwriters and their respective affiliates are full service financial institutions engaged in various activities, which may include securities trading, commercial and investment banking, financial advisory, investment management, principal investment, hedging, financing and brokerage activities. Certain of the underwriters and their respective affiliates have in the past performed commercial banking, investment banking and advisory services for us from time to time for which they have received customary fees and reimbursement of expenses and may, from time to time, engage in transactions with and perform services for us in the ordinary course of their business for which they may receive customary fees and reimbursement of expenses. In the ordinary course of their various business activities, the underwriters and their respective affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments (which may include bank loans and/or credit default swaps) for their own account and for the accounts of their customers and may at any time hold long and short positions in such securities and instruments. Such investment and securities activities may involve our securities and instruments. The underwriters and their respective affiliates may also make investment recommendations and/or publish or express independent research views in respect of such securities or financial instruments and may hold, or recommend to clients that they acquire, long and/or short positions in such securities and instruments. In addition, affiliates of some of the underwriters are lenders, and in some cases agents or managers for the lenders, under ADP’s credit facilities. If any of the underwriters or their affiliates have a lending relationship with us, certain of those underwriters or their affiliates routinely hedge, and certain other of those underwriters may hedge, their credit exposure to us consistent with their customary risk management policies. Typically, these underwriters and their

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affiliates would hedge such exposure by entering into transactions which consist of either the purchase of credit default swaps or the creation of short positions in our securities, including potentially the notes offered hereby. Any such credit default swaps or short positions could adversely affect future trading prices of the notes offered hereby. In connection with the issuance of the Notes, we may enter into interest rate swap agreements with financial institutions, which may include one or more of the underwriters or their affiliates. In addition, certain of the underwriters and their affiliates are customers of ADP.

In addition, certain of the underwriters and their affiliates may act as agents or lenders under our credit facilities and hold positions in our outstanding securities. To the extent we use any net proceeds of this offering to repurchase existing debt and any of the underwriters or their affiliates own such existing debt that is purchased with the proceeds of this offering, they may receive proceeds from this offering through the repurchase of such existing debt.

We have agreed to indemnify the underwriters against certain liabilities, including liabilities under the Securities Act, or to contribute to payments the underwriters may be required to make because of any of those liabilities.

In addition, U.S. Bancorp Investments, Inc., one of the underwriters, is an affiliate of the trustee under the indenture governing the Notes.

Notice to Prospective Investors in Canada

The Notes may be sold in Canada only to purchasers purchasing, or deemed to be purchasing, as principal that are accredited investors, as defined in National Instrument 45-106 Prospectus Exemptions or subsection 73.3(1) of the Securities Act (Ontario), and are permitted clients, as defined in National Instrument 31-103 Registration Requirements, Exemptions and Ongoing Registrant Obligations. Any resale of the Notes must be made in accordance with an exemption from, or in a transaction not subject to, the prospectus requirements of applicable securities laws. The underwriters may reject any order for Notes in whole or in part.

Securities legislation in certain provinces or territories of Canada may provide a purchaser with remedies for rescission or damages if this prospectus supplement or the accompanying prospectus (including any amendment thereto) contains a misrepresentation, provided that the remedies for rescission or damages are exercised by the purchaser within the time limit prescribed by the securities legislation of the purchaser’s province or territory. The purchaser should refer to any applicable provisions of the securities legislation of the purchaser’s province or territory for particulars of these rights or consult with a legal advisor.

Pursuant to section 3A.3 (or, in the case of securities issued or guaranteed by the government of a non-Canadian jurisdiction, section 3A.4) of National Instrument 33-105 Underwriting Conflicts (NI 33-105), the underwriters are not required to comply with the disclosure requirements of NI 33-105 regarding underwriter conflicts of interest in connection with this offering.

Notice to Prospective Investors in the European Economic Area

The Notes are not intended to be offered, sold or otherwise made available to and should not be offered, sold or otherwise made available to any retail investor in the European Economic Area (“EEA”). For these purposes, (a) a retail investor means a person who is one (or more) of: (i) a retail client as defined in point (11) of Article 4(1) of Directive 2014/65/EU (as amended or superseded, “MiFID II”); or (ii) a customer within the meaning of Directive (EU) 2016/97 (as amended or superseded, the “Insurance Distribution Directive”), where that customer would not qualify as a professional client as defined in point (10) of Article 4(1) of MiFID II; or (iii) not a qualified investor as defined in Regulation (EU) 2017/1129 (as amended or superseded, the “Prospectus Regulation”) and (b) the expression “offer” includes the communication in any form and by any means of sufficient information on the terms of the offer and the notes to be offered so as to enable an investor to decide to

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purchase or subscribe for the notes. Consequently no key information document required by Regulation (EU) No 1286/2014 (as amended or superseded, the “PRIIPs Regulation”) for offering or selling the Notes or otherwise making them available to retail investors in the EEA has been prepared and therefore offering or selling the Notes or otherwise making them available to any retail investor in the EEA may be unlawful under the PRIIPs Regulation. This prospectus supplement and the accompanying prospectus have been prepared on the basis that any offer of the Notes in any Member State of the EEA will be made pursuant to an exemption under the Prospectus Regulation from the requirement to publish a prospectus for offers of the Notes. This prospectus supplement and the accompanying prospectus are not a prospectus for the purposes of the Prospectus Regulation. References to Regulations or Directives include, in relation to the United Kingdom, those Regulations or Directives.

The above selling restriction is in addition to any other selling restrictions set out below.

Notice to Prospective Investors in the United Kingdom

The Notes are not intended to be offered, sold or otherwise made available to and should not be offered, sold or otherwise made available to any retail investor in the United Kingdom (the “UK”). For these purposes, (a) a retail investor means a person who is one (or more) of: (i) a retail client, as defined in point (8) of Article 2 of Regulation (EU) No 2017/565 as it forms part of domestic law by virtue of the European Union (Withdrawal) Act 2018, as amended by the European Union (Withdrawal Agreement) Act 2020 (“EUWA”); or (ii) a customer within the meaning of the provisions of the UK’s Financial Services and Markets Act 2000 (the “FSMA”) and any rules or regulations made under the FSMA to implement the Insurance Distribution Directive, where that customer would not qualify as a professional client, as defined in point (8) of Article 2(1) of Regulation (EU) No 600/2014 as it forms part of domestic law by virtue of the EUWA; or (iii) not a qualified investor as defined in Article 2 of the Prospectus Regulation as it forms part of domestic law by virtue of the EUWA (the “UK Prospectus Regulation”); and (b) the expression “offer” includes the communication in any form and by any means of sufficient information on the terms of the offer and the Notes to be offered so as to enable an investor to decide to purchase or subscribe for the Notes. Consequently, no key information document required by Regulation (EU) No 1286/2014 as it forms part of domestic law by virtue of the EUWA (the “UK PRIIPs Regulation”) for offering or selling the Notes or otherwise making them available to retail investors in the UK has been prepared and therefore offering or selling the Notes or otherwise making them available to any retail investor in the UK may be unlawful under the UK PRIIPs Regulation. This prospectus supplement and the accompanying prospectus have been prepared on the basis that any offer of the Notes in the UK will be made pursuant to an exemption under the UK Prospectus Regulation from the requirement to publish a prospectus for any offer of the Notes. This prospectus supplement and the accompanying prospectus are not a prospectus for the purposes of the UK Prospectus Regulation.

In the UK, this prospectus supplement and the accompanying prospectus are being distributed only to, and are directed only at, persons who are “qualified investors” (as defined in the Prospectus Regulation as it forms part of domestic law by virtue of the UK Prospectus Regulation) who are (i) persons having professional experience in matters relating to investments falling within Article 19(5) of the Financial Services and Markets Act 2000 (Financial Promotion) Order 2005 (as amended, the “Order”), (ii) high net worth entities falling within Article 49(2)(a) to (d) of the Order, or (iii) persons to whom it would otherwise be lawful to distribute it, all such persons together being referred to as “Relevant Persons.” In the UK, the Notes are only available to, and any invitation, offer or agreement to subscribe, purchase or otherwise acquire such Notes will be engaged in only with, Relevant Persons. This prospectus supplement and the accompanying prospectus and their contents are confidential and should not be distributed, published or reproduced (in whole or in part) or disclosed by any recipients to any other person in the UK. Any person in the UK that is not a Relevant Person should not act or rely on this prospectus supplement and the accompanying prospectus or their contents. The Notes are not being offered to the public in the UK.

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Notice to Prospective Investors in France

Neither this prospectus supplement nor any other offering material relating to the Notes described in this prospectus supplement has been submitted to the clearance procedures of the Autorité des Marchés Financiers or of the competent authority of another member state of the European Economic Area and notified to the Autorité des Marchés Financiers. The Notes have not been offered or sold and will not be offered or sold, directly or indirectly, to the public in France. Neither this prospectus supplement nor any other offering material relating to the Notes has been or will be:

Such offers, sales and distributions will be made in France only:

The Notes may be resold directly or indirectly, only in compliance with articles L.411-1, L.411-2, L.412-1 and L.621-8 through L.621-8-3 of the French Code monétaire et financier.

Notice to Prospective Investors in Hong Kong

Each underwriter (i) has not offered or sold and will not offer or sell in Hong Kong, by means of any document, any Notes other than (a) to “professional investors” as defined in the Securities and Futures Ordinance (Cap. 571 of the Laws of Hong Kong) (the “SFO”) and any rules made thereunder or (b) in other circumstances which do not result in the document being a “prospectus” as defined in the Companies (Winding Up and Miscellaneous Provisions) Ordinance (Cap. 32 of the Laws of Hong Kong) or which do not constitute an offer to the public within the meaning of that Ordinance and (ii) has not issued or had in its possession for the purposes of issue, and will not issue or have in its possession for the purposes of issue, whether in Hong Kong or elsewhere, any advertisement, invitation or document relating to the Notes, which is directed at, or the contents of which are likely to be accessed or read by, the public of Hong Kong (except if permitted to do so under the securities laws of Hong Kong) other than with respect to the Notes which are or are intended to be disposed of only to persons outside Hong Kong or only to “professional investors” as defined in the SFO and any rules made thereunder.

Notice to Prospective Investors in Japan

The Notes have not been and will not be registered pursuant to Article 4, Paragraph 1 of the Financial Instruments and Exchange Law of Japan (the “Financial Instruments and Exchange Law”) and each underwriter has agreed that it will not offer or sell the Notes, directly or indirectly, in Japan or to, or for the benefit of, any “resident” of Japan (which term as used herein means any person resident in Japan, including any corporation or other entity organized under the laws of Japan), or to others for re-offering or resale, directly or indirectly, in Japan or to or for the benefit of a resident of Japan, except pursuant to an exemption from the registration requirements of, and otherwise in compliance with, the Financial Instruments and Exchange Law and any other applicable laws, regulations and ministerial guidelines of Japan in effect at the relevant time.

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Notice to Prospective Investors in Singapore

This prospectus supplement and the accompanying prospectus have not been registered as a prospectus with the Monetary Authority of Singapore. Accordingly, each underwriter has represented and agreed that it has not offered or sold any Notes or caused the Notes to be made the subject of an invitation for subscription or purchase and will not offer or sell any Notes or cause the Notes to be made the subject of an invitation for subscription or purchase, and has not circulated or distributed, nor will it circulate or distribute, this prospectus supplement and the accompanying prospectus or any other document or material in connection with the offer or sale, or invitation for subscription or purchase, of the Notes, whether directly or indirectly, to any person in Singapore other than:

Where the Notes are subscribed or purchased under Section 275 of the SFA by a relevant person which is:

securities or securities-based derivatives contracts (each term as defined in Section 2(1) of the SFA) of that corporation or the beneficiaries’ rights and interest (howsoever described) in that trust shall not be transferred within six months after that corporation or that trust has acquired the notes pursuant to an offer made under Section 275 of the SFA except:

Singapore Securities and Futures Act Product Classification— Solely for the purposes of its obligations pursuant to Sections 309B(1)(a) and 309B(1)(c) of the SFA, the Company has determined, and hereby notifies all relevant persons (as defined in Section 309A of the SFA) that the Notes are “prescribed capital markets products” (as defined in the Securities and Futures (Capital Markets Products) Regulations 2018) and “Excluded Investment Products” (as defined in MAS Notice SFA 04-N12: Notice on the Sale of Investment Products and MAS Notice FAA-N16: Notice on Recommendations on Investment Products).

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LEGAL MATTERS

Certain matters pertaining to the Notes will be passed upon for ADP by David Kwon, Esq., Corporate Vice President and Chief Legal Officer of ADP. The validity of the Notes and certain matters pertaining to the Notes will be passed upon for ADP by Davis Polk & Wardwell LLP, New York, New York, and for the underwriters by Simpson Thacher & Bartlett LLP, New York, New York.

EXPERTS

The financial statements of Automatic Data Processing, Inc. as of June 30, 2024 and 2023, and for each of the three years in the period ended June 30, 2024, incorporated by reference in this prospectus by reference to Automatic Data Processing, Inc.’s annual report on Form 10-K for the year ended June 30, 2024, and the effectiveness of Automatic Data Processing, Inc.’s internal control over financial reporting, have been audited by Deloitte & Touche LLP, an independent registered public accounting firm, as stated in their reports. Such financial statements are incorporated by reference in reliance upon the reports of such firm given their authority as experts in accounting and auditing.

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PROSPECTUS

Automatic Data Processing, Inc.

Debt Securities

We may offer debt securities from time to time. Specific terms of these securities will be provided in supplements to this prospectus. You should read this prospectus and any supplement carefully before you invest.

Investing in these securities involves certain risks. See “Risk Factors” beginning on page 17 of our annual report on Form 10-K for the year ended June 30, 2024, which is incorporated by reference herein, as well as in any other recently filed quarterly or current reports. The prospectus supplement applicable to each series of securities we offer may contain a discussion of additional risks applicable to an investment in us and the securities we are offering under that prospectus supplement.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities, or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

This prospectus may not be used to sell securities unless accompanied by a prospectus supplement.

The date of this prospectus is September 4, 2024

We have not authorized anyone to provide any information other than that contained or incorporated by reference in this prospectus, any accompanying prospectus supplement or in any free writing prospectus prepared by or on behalf of us or to which we have referred you. We take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. We are not making an offer of these securities in any state or other jurisdiction where the offer is not permitted. You should not assume that the information contained in or incorporated by reference in this prospectus or any prospectus supplement or in any free writing prospectus is accurate as of any date other than their respective dates. Our business, financial condition, results of operations and prospects may have changed since those dates. The terms “ADP,” “we,” “us,” and “our” refer to Automatic Data Processing, Inc. and its subsidiaries.

TABLE OF CONTENTS

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we filed with the SEC utilizing a “shelf” registration process. Under this shelf process, we may sell the debt securities described in this prospectus in one or more offerings. This prospectus provides you with a general description of the securities we may offer. Each time we sell securities pursuant to the registration statement, we will provide a prospectus supplement that will contain specific information about the terms of that offering. The prospectus supplement may also add, update or change information contained or incorporated by reference in this prospectus. You should read both this prospectus and any prospectus supplement together with additional information described under the heading “Where You Can Find More Information.”

We have filed or incorporated by reference exhibits to the registration statement of which this prospectus forms a part. You should read the exhibits carefully for provisions that may be important to you.

AUTOMATIC DATA PROCESSING, INC.

Today, Automatic Data Processing, Inc. is one of the world’s leading global technology companies providing comprehensive cloud-based human capital management (HCM) solutions that unite HR, payroll, talent, time, tax and benefits administration. Our unmatched experience, expertise, insights and cutting-edge technology have transformed HCM from an administrative challenge to a strategic business advantage. Tailored to meet the needs of businesses of all sizes, we help them work smarter today so they can have more success tomorrow. We serve over 1.1 million clients and pay over 42 million workers in over 140 countries and territories.

SPECIAL NOTE ON FORWARD-LOOKING STATEMENTS

This prospectus and documents incorporated by reference in this prospectus contain “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Statements that are not historical in nature, and which may be identified by the use of words like “outlook,” “expects,” “assumes,” “projects,” “anticipates,” “estimates,” “we believe,” “could,” “is designed to” and other words of similar meaning, are forward-looking statements. These statements are based on management’s expectations and assumptions and depend upon or refer to future events or conditions and are subject to risks and uncertainties that may cause actual results to differ materially from those expressed. Factors that could cause actual results to differ materially from those contemplated by the forward-looking statements or that could contribute to such difference include:

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The factors identified above are not exhaustive. ADP disclaims any obligation to update any forward-looking statements, whether as a result of new information, future events, or otherwise, except as required by law. These risks and uncertainties, along with the risk factors discussed under “Item 1A. Risk Factors” in ADP’s most recently filed Annual Report on Form 10-K should be considered in evaluating any forward-looking statements contained herein.

RISK FACTORS

An investment in our securities involves risks. You should carefully consider each of the risks described in the section entitled “Risk Factors” in our Annual Report on Form 10-K for the fiscal year ended June 30, 2024, filed with the SEC on August 7, 2024, as such factors may be updated from time to time in our periodic filings with the SEC, which are accessible on the SEC’s website at www.sec.gov, and all of the other information included or incorporated by reference in this prospectus before deciding to invest in any of our securities.

USE OF PROCEEDS

Except as otherwise disclosed in a prospectus supplement, the net proceeds from the sale of the securities by us will be used for general corporate purposes.

DESCRIPTION OF DEBT SECURITIES

The debt securities will be our direct senior unsecured general obligations. The debt securities will be issued in one or more series under an indenture dated as of August 13, 2020, between us and U.S. Bank Trust Company, National Association (as successor in interest to U.S. Bank National Association), as trustee.

We have summarized all of the material provisions of the indenture below. The following description of the provisions of the indenture does not purport to be complete and is subject to, and qualified in its entirety by, reference to the indenture, which has been filed as an exhibit to the registration statement of which this prospectus forms a part, and you should read the indenture for provisions that may be important to you. In the summary below, we have included references to section numbers of the indenture so that you can easily locate these provisions.

General

The debt securities will be our direct senior unsecured general obligations. The debt securities will rank equally with all of our other senior and unsubordinated debt.

The provisions of the indenture allow us to “reopen” a previous issue of a series of debt securities and issue additional debt securities of that series.

A prospectus supplement relating to any series of debt securities being offered will include specific terms relating to the offering. The terms will be established in an officers’ certificate or a supplemental indenture. The officers’ certificate or supplemental indenture will be signed at the time of issuance and will contain important

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information. The officers’ certificate or supplemental indenture will be filed as an exhibit to a Current Report on Form 8-K of ADP, which will be publicly available. The officers’ certificate or supplemental indenture will include some or all of the following terms for a particular series of debt securities:

Fixed Rate Debt Securities

Each fixed rate debt security will mature on the date specified in the applicable prospectus supplement.

Each fixed rate debt security will bear interest from the date of issuance at the annual rate stated on its face until the principal is paid or made available for payment. Interest on fixed rate debt securities will be computed on the basis of a 360-day year of twelve 30-day months. Interest on fixed rate debt securities will accrue from and including the most recent interest payment date in respect of which interest has been paid or duly provided for, or, if no interest has been paid or duly provided for, from and including the issue date or any other date specified in a prospectus supplement on which interest begins to accrue. Interest will accrue to but excluding the next interest payment date, or, if earlier, the date of maturity or earlier redemption or repayment, as the case may be.

Payments of interest on fixed rate debt securities will be made on the interest payment dates specified in the applicable prospectus supplement. However, if the first interest payment date is less than 15 days after the date of issuance, interest will not be paid on the first interest payment date, but will be paid on the second interest payment date.

Unless otherwise specified in the applicable prospectus supplement, if any scheduled interest payment date, maturity date or date of redemption or repayment is not a business day, then we may pay the applicable interest, principal and premium, if any, on the next succeeding business day, and no additional interest will accrue during the period from and after the scheduled interest payment date, maturity date or date of redemption or repayment. (section 13.07)

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A fixed rate debt security may pay a level amount in respect of both interest and principal amortized over the life of the debt security. Payments of principal and interest on amortizing debt securities will be made on the interest payment dates specified in the applicable prospectus supplement, and at maturity or upon any earlier redemption or repayment. Payments on amortizing debt securities will be applied first to interest due and payable and then to the reduction of the unpaid principal amount. We will provide to the original purchaser, and will furnish to subsequent holders upon request to us, a table setting forth repayment information for each amortizing debt security.

Optional Redemption

Unless the prospectus supplement relating to any series of debt securities provides otherwise with respect to such series, each series of debt securities will be redeemable in whole at any time or in part from time to time, at our option, at a redemption price equal to the greater of:

In each case we will pay accrued and unpaid interest on the principal amount to be redeemed to the date of redemption.

“Comparable Treasury Issue” means the United States Treasury security selected by the Independent Investment Banker as having an actual or interpolated maturity comparable to the remaining term (“Remaining Life”) of the series of debt securities to be redeemed that would be utilized, at the time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of comparable maturity to the remaining term of such series of debt securities.

“Comparable Treasury Price” means, with respect to any redemption date, (1) the average of the Reference Treasury Dealer Quotations for such redemption date, after excluding the highest and lowest Reference Treasury Dealer Quotations, or (2) if the Independent Investment Banker obtains fewer than four such Reference Treasury Dealer Quotations, the average of all such quotations.

“Independent Investment Banker” means the investment banking institution or institutions specified in the applicable prospectus supplement and their respective successors, or, if such firms or the successors, if any, to such firm or firms, as the case may be, are unwilling or unable to select the Comparable Treasury Issue, an independent investment banking institution of national standing appointed by us.

“Reference Treasury Dealer” means the investment banking institutions specified as such in the applicable prospectus supplement; provided, however, that if any of them ceases to be a primary U.S. Government securities dealers (each a “Primary Treasury Dealer”), we will substitute another Primary Treasury Dealer.

“Reference Treasury Dealer Quotations” means, with respect to each Reference Treasury Dealer and any redemption date, the average, as determined by the Independent Investment Banker, of the bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted in writing to the Independent Investment Banker by such Reference Treasury Dealer at 5:00 p.m., New York City time, on the third business day preceding such redemption date (or date of deposit in the case of a satisfaction and discharge).

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“Treasury Rate” means, with respect to any redemption date, the rate per year equal to:

The Treasury Rate will be calculated on the third business day preceding the redemption date (or date of deposit in the case of a satisfaction and discharge). As used in the immediately preceding sentence and in the definition of “Reference Treasury Dealer Quotations” above, the term “business day” means any day that is not a Saturday, Sunday or other day on which commercial banks in New York City are authorized or required by law to remain closed.

Notice of any redemption will be electronically delivered or mailed at least 30 but not more than 60 days before the redemption date to each holder of record of the series of debt securities to be redeemed at its registered address. The notice of redemption will state, among other things, the amount of the series of debt securities to be redeemed, the redemption date, the CUSIP(s) and ISIN number(s), the manner in which the redemption price will be calculated and the place or places that payment will be made upon presentation and surrender of the series of debt securities to be redeemed. If less than all of a series of debt securities are to be redeemed at our option, the trustee will select by lot or in such other manner in accordance with the customary procedures of the depositary, the debt securities of that series, or portions of the debt securities of that series, to be redeemed. Unless we default in the payment of the redemption price with respect to any debt securities called for redemption, interest will cease to accrue on such debt securities at the redemption date. (sections 3.02 and 3.03)

ADP will not be required (i) to issue, register the transfer of or exchange any series of debt securities during a period beginning at the opening of business 15 days before the day of mailing of a notice of redemption and ending at the close of business on the day of such mailing, or (ii) to register the transfer of or exchange any debt securities of any series so selected for redemption in whole or in part, except the unredeemed portion of any such series of debt securities being redeemed in part. (section 2.05)

Covenants

Under the indenture, ADP agrees, among other things, to pay the interest, principal and any premium on the debt securities when due (section 4.01), and to maintain a place of payment (section 4.02). However, the covenants under the indenture do not, among other things:

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The applicable prospectus supplement may contain additional covenants that impose various restrictions on ADP and, as a result, afford the holders of its securities certain protections. You should review the full text of the covenants in the applicable prospectus supplement and supplemental indenture to evaluate the covenants.

Consolidation, Merger or Sale

We may not consolidate with or merge into, or convey, transfer or lease all or substantially all of our properties and assets to, any person unless:

Any such successor, acquiror or lessor of such assets will succeed to every right and power of ADP under the indenture. Thereafter, except in the case of a lease, the predecessor or transferor of such assets will be relieved of all obligations and covenants under the indenture and the debt securities. (sections 10.01 and 10.02)

This covenant would not apply to any recapitalization transaction, a change of control of ADP or a highly leveraged transaction, unless the transaction or change of control were structured to include a merger or consolidation or conveyance, transfer or lease of all or substantially all of our properties and assets as set forth in the indenture.

Events of Default Under the Indenture

The following are events of default under the indenture with respect to any series of debt securities issued:

If, with regard to any series, an event of default resulting from a failure to pay principal, any premium or interest occurs and is continuing, the trustee or the holders of at least 25% in aggregate principal amount of the outstanding debt securities of that series may declare the principal of all debt securities of that series immediately due and payable. (section 6.01)

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If an event of default other than a failure to pay principal, any premium or interest occurs and is continuing, the trustee or the holders of at least 25% in aggregate principal amount of the outstanding debt securities of all affected series (all such series voting together as a single class) may declare the principal of all debt securities of such affected series immediately due and payable. (section 6.01)

If an event of default relating to events in bankruptcy or insolvency of ADP occurs and is continuing, then the entire principal amount of all of the debt securities outstanding, and the interest accrued thereon, if any, will automatically become due and payable immediately, without any declaration or other act by the trustee or any holder.

The holders of a majority in aggregate principal amount of the outstanding debt securities of all affected series (voting together as a single class) may waive any past default with respect to such series and its consequences, except a default or events of default regarding payment of principal, any premium or interest, in which case the holders of a majority in aggregate principal amount of the outstanding debt securities of each affected series shall vote to waive such default or event of default as a separate class. Such a waiver will eliminate the default. (section 6.06)

Unless otherwise specified in the indenture, if an event of default occurs and is continuing, the trustee will be under no obligation to exercise any of its rights or powers under the indenture unless the holders of the debt securities have offered the trustee security or indemnity reasonably satisfactory to it against the costs, expenses and liabilities that it might incur. The holders of a majority in aggregate principal amount of the outstanding debt securities of all series affected by an event of default, voting together as a single class, or, in the event of a default in the payment of principal, any premium or interest, the holders of a majority of the aggregate principal amount outstanding of each affected series voting as a separate class, will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee, or exercising any trust or power conferred on the trustee with respect to the debt securities of such series, provided that:

A holder of the debt securities of a particular series will only have the right to institute a proceeding under the indenture or to appoint a receiver or trustee, or to seek other remedies, in each case with respect to such series of debt securities, if:

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Discharge, Defeasance and Covenant Defeasance

We can discharge or defease our obligations under the indenture as set forth below.

We may discharge our obligations to the beneficial owners of any series of debt securities that have not already been delivered to the trustee for cancellation and that have either become due and payable or are by their terms to become due and payable within one year (or to be called for redemption within one year). We may effect a discharge by irrevocably depositing with the trustee money or government obligations or a combination thereof, as trust funds, in an amount sufficient to pay when due, whether at maturity, upon redemption or otherwise, the principal of, and premium, if any, and interest on, the debt securities.

Unless otherwise provided in the applicable prospectus supplement, we may also discharge any and all of our obligations to the beneficial owners of any series of debt securities at any time (“legal defeasance”). We also may be released from the obligations imposed by any covenants of any outstanding series of debt securities and provisions of the indenture, and we may omit to comply with those covenants without creating an event of default (“covenant defeasance”). We may effect legal defeasance and covenant defeasance only if, among other things:

Although we may discharge or defease our obligations under the indenture as described in the two preceding paragraphs, we may not avoid, among other things, our duty to register the transfer or exchange of any series of debt securities, to replace any temporary, mutilated, destroyed, lost or stolen series of debt securities or to maintain an office or agency in respect of any series of debt securities.

We may exercise our legal defeasance option notwithstanding our prior exercise of our covenant defeasance option.

Modification of Indenture; Waiver

Without the consent of any holders of debt securities, ADP and the trustee may change the indenture:

The rights of holders of a series of debt securities may be changed by ADP and the trustee with the written consent of the holders of a majority of the aggregate principal amount of the outstanding debt securities of all

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series then outstanding under the indenture (all such series voting together as a single class). However, the following changes may only be made with the consent of each holder of debt securities of each series affected by the change:

Form, Exchange, and Transfer

The debt securities of each series will be issued in fully registered form without coupons in minimum denominations of $2,000 and integral multiples of $1,000 in excess thereof. The indenture provides that debt securities of a series may be issued in temporary or permanent global form and may be issued as book-entry securities that will be deposited with The Depository Trust Company or another depositary named by ADP and identified in a prospectus supplement with respect to such series. (sections 2.03, 2.06 and 2.11)

A holder of debt securities of any series can exchange such debt securities for other debt securities of the same series, in any authorized denomination and with the same terms and aggregate principal amount. A holder may present debt securities for exchange or for registration of transfer at the office of the security registrar or at the office of any transfer agent designated by ADP for such purpose. Unless otherwise provided in the debt securities to be transferred or exchanged, no service charge will be made for any registration of transfer or exchange, but ADP may require payment of any related taxes or other governmental charges. The prospectus supplement will name the security registrar and any transfer agent initially designated for any series of debt securities. ADP may at any time change the transfer agent by written notice delivered to the trustee. (section 2.05)

If the debt securities of any series are to be redeemed, ADP will not be required to:

Rights and Duties of the Trustee

The trustee, except when there is an event of default, will perform only those duties as are specifically stated in the indenture. If an event of default has occurred with respect to any series of debt securities, the trustee must exercise with respect to such debt securities the rights and powers it has under the indenture and use the same degree of care and skill as a prudent person would exercise or use in the conduct of his or her own affairs. Except as provided in the preceding sentence, the trustee is not required to exercise any of the powers given it by the indenture at the request of any holder of debt securities unless it is offered security or indemnity reasonably satisfactory to it against the costs, expenses and liabilities that it might incur. The trustee is not required to spend or risk its own money or otherwise become financially liable while performing its duties or exercising its rights or powers unless it reasonably believes that it will be repaid or receive adequate indemnity. The trustee will not be deemed to have any notice of any default or event of default unless a responsible officer of the trustee has actual knowledge of or receives written notice of the default which specifies the existence of such default or event of default with respect to the affected securities and the indenture. Furthermore, the rights and protections

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of the trustee, including its right of indemnification under the indenture, extend to the trustee’s officers, directors, agents and employees, and will survive the trustee’s resignation and removal and final payment of the securities. (sections 7.01 and 7.02)

Payment and Paying Agents

We will pay interest on any debt securities to the person in whose name the debt securities are registered on the regular record date for the applicable interest payment date. (sections 2.03 and 3.03)

We will pay principal, any premium and interest on the debt securities of a particular series at the office of one or more paying agents that we designate for that series. Unless otherwise stated in the applicable officers’ certificate, supplemental indenture and prospectus supplement, we will initially designate the corporate trust office of the trustee in the City of New York as our sole paying agent. We will be required to maintain a paying agent in each place of payment for the debt securities. (sections 4.01, 4.02 and 4.03)

All money we pay to a paying agent or the trustee for the payment of principal, any premium or interest on any debt security which remains unclaimed for a period of two years after the principal, premium or interest has become due and payable will, upon our request, be repaid to us, and the holder of the debt security may then look only to us for payment of those amounts. (section 11.05)

Governing Law

The indenture and the debt securities will be governed by and interpreted in accordance with the laws of the State of New York. (section 13.05)

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PLAN OF DISTRIBUTION

ADP may sell the securities in one or more of the following ways (or in any combination) from time to time:

The applicable prospectus supplement will state the terms of the offering of the securities, including:

Any initial public offering price and any discounts or concessions allowed or reallowed or paid to dealers may be changed from time to time.

If we use underwriters in the sale, the securities will be acquired by the underwriters for their own account and may be resold from time to time in one or more transactions, including:

Unless otherwise stated in a prospectus supplement, the obligations of the underwriters to purchase any securities will be conditioned on customary closing conditions and the underwriters will be obligated to purchase all securities of a series, if any are purchased.

We may sell the securities through agents from time to time. The prospectus supplement will name any agent involved in the offer or sale of the securities and any commissions we pay to them. Generally, any agent will be acting on a best efforts basis for the period of its appointment.

We may authorize underwriters, dealers or agents to solicit offers by certain purchasers to purchase the securities from ADP at the public offering price set forth in the prospectus supplement pursuant to delayed delivery contracts providing for payment and delivery on a specified date in the future. The contracts will be subject only to those conditions set forth in the prospectus supplement, and the prospectus supplement will set forth any commissions paid for solicitation of these contracts.

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Underwriters and agents may be entitled under agreements entered into with ADP to indemnification by ADP against certain civil liabilities, including liabilities under the Securities Act, or to contribution with respect to payments which the underwriters or agents may be required to make. Underwriters and agents may be customers of, engage in transactions with, or perform services for ADP and its affiliates in the ordinary course of business.

Each series of securities will be a new issue of securities and will have no established trading market. Any underwriters to whom securities are sold for public offering and sale may make a market in the securities, but such underwriters will not be obligated to do so and may discontinue any market making at any time without notice. The securities may or may not be listed on a national securities exchange.

VALIDITY OF SECURITIES

The validity of the securities in respect of which this prospectus is being delivered will be passed on for us by Davis Polk & Wardwell LLP.

EXPERTS

The financial statements of Automatic Data Processing, Inc. incorporated by reference in this prospectus, and the effectiveness of Automatic Data Processing, Inc.’s internal control over financial reporting, have been audited by Deloitte & Touche LLP, an independent registered public accounting firm, as stated in their reports. Such financial statements are incorporated by reference in reliance upon the reports of such firm given their authority as experts in accounting and auditing.

WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and current reports, proxy statements and other information with the SEC. The SEC maintains an Internet site at http://www.sec.gov, from which interested persons can electronically access our SEC filings, including the registration statement of which this prospectus forms a part and the exhibits and schedules thereto.

We also maintain a website that contains additional information about us at www.adp.com. We are not incorporating the contents of the website into this prospectus.

This prospectus is part of a registration statement on Form S-3 that we filed with the SEC. You may obtain the full registration statement from the SEC or us, as indicated below. This prospectus, which is part of the registration statement, does not contain all of the information set forth in the registration statement and the exhibits and schedules to the registration statement. We filed or incorporated by reference the form of indenture and other documents establishing the terms of the offered securities as exhibits to the registration statement. Statements in this prospectus or any supplement about these documents are summaries. You should refer to the actual documents for a more complete description of the relevant matters.

INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE

The SEC allows us to “incorporate by reference” the information we file with the SEC, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is an important part of this prospectus, and information that we file later with the SEC will automatically update and supersede this information. We incorporate by reference into this prospectus the documents listed below and any future filings we will make with the SEC pursuant to Section 13(a), 13(c), 14 or 15(d) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), as of the date of the filing of the registration statement of which this prospectus is a part:

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With respect to each offering of securities under this prospectus, we also incorporate by reference all documents subsequently filed with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act prior to termination of that offering under this prospectus and any prospectus supplement (other than, in each case, documents or information deemed to have been furnished and not filed in accordance with applicable SEC rules).

Unless specifically stated to the contrary, none of the information that we disclose under Items 2.02 or 7.01 of any Current Report on Form 8-K that we may from time to time furnish to the SEC or any other document or information deemed to have been furnished and not filed with the SEC will be incorporated by reference into, or otherwise included in, this prospectus.

Any statement contained in this prospectus or in a document (or part thereof) incorporated or considered to be incorporated by reference in this prospectus shall be considered to be modified or superseded for purposes of this prospectus to the extent that a statement contained in this prospectus or in any other subsequently filed document (or part thereof) that is or is considered to be incorporated by reference in this prospectus modifies or supersedes that statement. The modifying or superseding statement need not state that it has modified or superseded a prior statement or include any other information set forth in the document that it modifies or supersedes. Any statement so modified or superseded shall not be considered, except as so modified or superseded, to constitute any part of this prospectus.

ADP will provide without charge, upon written or oral request, a copy of any or all of the documents which are incorporated by reference in this prospectus, other than exhibits which are specifically incorporated by reference into those documents. Requests should be directed to Investor Relations, Automatic Data Processing, Inc., One ADP Boulevard, Roseland, New Jersey 07068, telephone number (973) 974-5858.

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$1,000,000,000

Automatic Data Processing, Inc.

$1,000,000,000 4.450% Senior Notes due 2034

PROSPECTUS SUPPLEMENT

Joint Book-Running Managers

BofA Securities

J.P. Morgan

Morgan Stanley

BNP PARIBAS

Deutsche Bank Securities

Wells Fargo Securities

Co-Managers

Barclays

MUFG

PNC Capital Markets LLC

RBC Capital Markets

BMO Capital Markets

US Bancorp

Fifth Third Securities

Siebert Williams Shank

ING

IMI – Intesa Sanpaolo

SOCIETE GENERALE

HSBC

Scotiabank

Academy Securities

BNY Capital Markets

Huntington Capital Markets

TD Securities

BOK Financial Securities, Inc.

Ramirez & Co., Inc.

September 4, 2024