BlackRock Credit Allocation Income Trust (BTZ) N-CSRCertified annual shareholder report (management investment company)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF REGISTERED MANAGEMENT

INVESTMENT COMPANIES

Investment Company Act file number: 811-21972

Name and address of agent for service: John M. Perlowski, Chief Executive Officer, BlackRock Credit Allocation Income Trust, 50 Hudson Yards, New York, NY 10001

Registrant’s telephone number, including area code: (800) 882-0052, Option 4

Date of fiscal year end: 12/31/2022

Date of reporting period: 12/31/2022

Item 1 – Report to Stockholders

(a) The Report to Shareholders is attached herewith.

BlackRock Core Bond Trust (BHK)

BlackRock Corporate High Yield Fund, Inc. (HYT)

BlackRock Credit Allocation Income Trust (BTZ)

BlackRock Floating Rate Income Trust (BGT)

Supplemental Information  (unaudited)

Section 19(a) Notices

BlackRock Core Bond Trust’s (BHK), BlackRock Corporate High Yield Fund, Inc.’s (HYT), BlackRock Credit Allocation Income Trust’s (BTZ) and BlackRock Floating Rate Income Trust’s (BGT) (collectively the “Trusts”, or individually a “Trust”) amounts and sources of distributions reported are estimates and are being provided to you pursuant to regulatory requirements and are not being provided for tax reporting purposes. The actual amounts and sources for tax reporting purposes will depend upon each Trust’s investment experience during its fiscal year and may be subject to changes based on tax regulations. Each Trust will provide a Form 1099-DIV each calendar year that will tell you how to report these distributions for U.S. federal income tax purposes.

December 31, 2022

Section 19(a) notices for the Trusts, as applicable, are available on the BlackRock website at blackrock.com.

Section 19(b) Disclosure

The Trusts, acting pursuant to a U.S. Securities and Exchange Commission (“SEC”) exemptive order and with the approval of each Trust’s Board of Trustees or Directors, as applicable (the “Board”), each has adopted a managed distribution plan, consistent with its investment objectives and policies, to support a level distribution of income, capital gains and/or return of capital (the “Plan”). In accordance with the Plans, the Trusts currently distribute the following fixed amounts per share on a monthly basis:

The fixed amounts distributed per share are subject to change at the discretion of each Trust’s Board. Under its Plan, each Trust will distribute all available net income to its shareholders as required by the Internal Revenue Code of 1986, as amended (the “Code”). If sufficient income (inclusive of net income and short-term capital gains) is not earned on a monthly basis, the Trusts will distribute long-term capital gains and/or return of capital to shareholders in order to maintain a level distribution. Each monthly distribution to shareholders is expected to be at the fixed amount established by the Board; however, each Trust may make additional distributions from time to time, including additional capital gain distributions at the end of the taxable year, if required to meet requirements imposed by the Code and/or the Investment Company Act of 1940, as amended (the “1940 Act”).

Shareholders should not draw any conclusions about each Trust’s investment performance from the amount of these distributions or from the terms of the Plan. Each Trust’s total return performance is presented in its financial highlights table.

The Board may amend, suspend or terminate a Trust’s Plan at any time without prior notice to the Trust’s shareholders if it deems such actions to be in the best interests of the Trust or its shareholders. The suspension or termination of the Plan could have the effect of creating a trading discount (if the Trust’s stock is trading at or above net asset value) or widening an existing trading discount. The Trusts are subject to risks that could have an adverse impact on their ability to maintain level distributions. Examples of potential risks include, but are not limited to, economic downturns impacting the markets, changes in interest rates, decreased market volatility, companies suspending or decreasing corporate dividend distributions and changes in the Code. Please refer to BHK, HYT and BGT’s prospectus for a more complete description of each Trust’s risks.

Table of Contents

The Benefits and Risks of Leveraging

The Trusts may utilize leverage to seek to enhance the distribution rate on, and net asset value (“NAV”) of, their common shares (“Common Shares”). However, there is no guarantee that these objectives can be achieved in all interest rate environments.

In general, the concept of leveraging is based on the premise that the financing cost of leverage, which is based on short-term interest rates, is normally lower than the income earned by a Trust on its longer-term portfolio investments purchased with the proceeds from leverage. To the extent that the total assets of each Trust (including the assets obtained from leverage) are invested in higher-yielding portfolio investments, each Trust’s shareholders benefit from the incremental net income. The interest earned on securities purchased with the proceeds from leverage (after paying the leverage costs) is paid to shareholders in the form of dividends, and the value of these portfolio holdings (less the leverage liability) is reflected in the per share NAV.

To illustrate these concepts, assume a Trust’s capitalization is $100 million and it utilizes leverage for an additional $30 million, creating a total value of $130 million available for investment in longer-term income securities. If prevailing short-term interest rates are 3% and longer-term interest rates are 6%, the yield curve has a strongly positive slope. In this case, a Trust’s financing costs on the $30 million of proceeds obtained from leverage are based on the lower short-term interest rates. At the same time, the securities purchased by a Trust with the proceeds from leverage earn income based on longer-term interest rates. In this case, a Trust’s financing cost of leverage is significantly lower than the income earned on a Trust’s longer-term investments acquired from such leverage proceeds, and therefore the holders of Common Shares (“Common Shareholders”) are the beneficiaries of the incremental net income.

However, in order to benefit shareholders, the return on assets purchased with leverage proceeds must exceed the ongoing costs associated with the leverage. If interest and other costs of leverage exceed a Trust’s return on assets purchased with leverage proceeds, income to shareholders is lower than if a Trust had not used leverage. Furthermore, the value of the Trusts’ portfolio investments generally varies inversely with the direction of long-term interest rates, although other factors can influence the value of portfolio investments. In contrast, the amount of each Trust’s obligations under its respective leverage arrangement generally does not fluctuate in relation to interest rates. As a result, changes in interest rates can influence the Trusts’ NAVs positively or negatively. Changes in the future direction of interest rates are very difficult to predict accurately, and there is no assurance that a Trust’s intended leveraging strategy will be successful.

The use of leverage also generally causes greater changes in each Trust’s NAV, market price and dividend rates than comparable portfolios without leverage. In a declining market, leverage is likely to cause a greater decline in the NAV and market price of a Trust’s shares than if the Trust were not leveraged. In addition, each Trust may be required to sell portfolio securities at inopportune times or at distressed values in order to comply with regulatory requirements applicable to the use of leverage or as required by the terms of leverage instruments, which may cause the Trust to incur losses. The use of leverage may limit a Trust’s ability to invest in certain types of securities or use certain types of hedging strategies. Each Trust incurs expenses in connection with the use of leverage, all of which are borne by shareholders and may reduce income to the shareholders. Moreover, to the extent the calculation of each Trust’s investment advisory fees includes assets purchased with the proceeds of leverage, the investment advisory fees payable to the Trusts’ investment adviser will be higher than if the Trusts did not use leverage.

Each Trust may utilize leverage through a credit facility or reverse repurchase agreements as described in the Notes to Financial Statements, if applicable.

Under the Investment Company Act of 1940, as amended (the “1940 Act”), each Trust is permitted to borrow money (including through the use of TOB Trusts) or issue debt securities up to 33 1/3% of its total managed assets. A Trust may voluntarily elect to limit its leverage to less than the maximum amount permitted under the 1940 Act. In addition, a Trust may also be subject to certain asset coverage, leverage or portfolio composition requirements imposed by its credit facility, which may be more stringent than those imposed by the 1940 Act.

Derivative Financial Instruments

The Trusts may invest in various derivative financial instruments. These instruments are used to obtain exposure to a security, commodity, index, market, and/or other assets without owning or taking physical custody of securities, commodities and/or other referenced assets or to manage market, equity, credit, interest rate, foreign currency exchange rate, commodity and/or other risks. Derivative financial instruments may give rise to a form of economic leverage and involve risks, including the imperfect correlation between the value of a derivative financial instrument and the underlying asset, possible default of the counterparty to the transaction or illiquidity of the instrument. Pursuant to Rule 18f-4 under the 1940 Act, among other things, the Trusts must either use derivative financial instruments with embedded leverage in a limited manner or comply with an outer limit on fund leverage risk based on value-at-risk. The Trusts’ successful use of a derivative financial instrument depends on the investment adviser’s ability to predict pertinent market movements accurately, which cannot be assured. The use of these instruments may result in losses greater than if they had not been used, may limit the amount of appreciation a Trust can realize on an investment and/or may result in lower distributions paid to shareholders. The Trusts’ investments in these instruments, if any, are discussed in detail in the Notes to Financial Statements.

Investment Objective

BlackRock Core Bond Trust’s (BHK) (the “Trust”) investment objective is to provide current income and capital appreciation. The Trust seeks to achieve its investment objective by investing, under normal market conditions, at least 75% of its managed assets in bonds that are investment grade quality at the time of investment. Under normal market conditions, the Trust intends to invest its assets primarily in a diversified portfolio of investment grade bonds, which may include, but are not limited to, corporate bonds, U.S. government and agency securities and mortgage-related securities. The Trust may invest up to 25% of its total managed assets in bonds that at the time of investment are rated Ba/BB or below by Moody’s Investors Service, Inc. (“Moody’s”), S&P Global Ratings, Fitch Ratings (“Fitch”) or another nationally recognized rating agency or bonds that are unrated but judged to be of comparable quality by the investment adviser. The Trust may invest up to 10% of its managed assets in bonds issued in foreign currencies. The Trust may invest directly in such securities or synthetically through the use of derivatives.

No assurance can be given that the Trust’s investment objective will be achieved.

Trust Information

Market Price and Net Asset Value Per Share Summary

GROWTH OF $10,000 INVESTMENT

Performance

Returns for the period ended December 31, 2022 were as follows:

Performance results may include adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles.

Past performance is not an indication of future results.

The Trust is presenting the performance of one or more indices for informational purposes only. The Trust is actively managed and does not seek to track or replicate the performance of any index. The index performance shown is not intended to be indicative of the Trust’s investment strategies, portfolio components or past or future performance.

More information about the Trust’s historical performance can be found in the “Closed End Funds” section of blackrock.com.

The following discussion relates to the Trust’s absolute performance based on NAV:

What factors influenced performance?

The Trust’s allocation to U.S. Treasuries weighed on return as interest rates rose sharply over the period. Exposure to a range of credit-oriented sectors including high yield corporate bonds, investment grade corporate bonds, non-U.S. corporate credit and emerging market bonds also detracted. Exposure to securitized assets including residential mortgage-backed securities (“MBS”), commercial mortgage-backed securities (“CMBS”) and asset-backed securities (“ABS”) detracted as well. Finally, holdings of municipal bonds also provided negative returns.

There were no material contributors to the Trust’s absolute performance over the period.

Derivatives were utilized by the Trust in order to hedge and/or take outright views on interest rates, credit risk and/or foreign exchange positions in the portfolio. The Trust’s use of derivatives detracted from performance during the period.

The Trust’s practice of maintaining a specified level of monthly distributions to shareholders did not have a material impact on the Trust’s investment strategy. The distribution policy resulted in return of capital for the period. Refer to the financial highlights and income tax information sections in this report for further information about the distributions.

Describe recent portfolio activity.

During the period, the Trust reduced exposure to riskier assets such as emerging markets debt in anticipation of a potential economic slowdown. The increased focus on quality was also reflected in increased allocations to investment grade corporate bonds and agency MBS. As interest rate volatility declined late in the period MBS became more attractive. The allocation to high yield corporate bonds was increased as the sector demonstrated resilience. Finally, the Trust made opportunistic allocations to ABS.

Describe portfolio positioning at period end.

At period end, the Trust maintained a diversified exposure within non-government spread sectors, including investment grade and high yield corporate bonds, CMBS, ABS and, to a lesser degree, non-agency MBS. The Trust also held exposure to government-related sectors such as U.S. Treasuries, agency debt and agency MBS.

The views expressed reflect the opinions of BlackRock as of the date of this report and are subject to change based on changes in market, economic or other conditions. These views are not intended to be a forecast of future events and are no guarantee of future results.

Overview of the Trust’s Total Investments

Investment Objective

BlackRock Corporate High Yield Fund, Inc.’s (HYT) (the “Trust”) primary investment objective is to provide shareholders with current income. The Trust’s secondary investment objective is to provide shareholders with capital appreciation. The Trust seeks to achieve its objectives by investing primarily in a diversified portfolio of fixed income securities which are rated at the time of investment to be below investment grade or, if unrated, are considered by the investment adviser to be of comparable quality. The Trust may invest directly in fixed income securities or synthetically through the use of derivatives.

No assurance can be given that the Trust’s investment objective will be achieved.

Trust Information

Market Price and Net Asset Value Per Share Summary

GROWTH OF $10,000 INVESTMENT

Performance

Returns for the period ended December 31, 2022 were as follows:

Performance results may include adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles.

Past performance is not an indication of future results.

The Trust is presenting the performance of one or more indices for informational purposes only. The Trust is actively managed and does not seek to track or replicate the performance of any index. The index performance shown is not intended to be indicative of the Trust’s investment strategies, portfolio components or past or future performance.

More information about the Trust’s historical performance can be found in the “Closed End Funds” section of blackrock.com.

The following discussion relates to the Trust’s absolute performance based on NAV:

What factors influenced performance?

High-yield bonds experienced sharp negative returns during the period, as persistent inflation, aggressive rate hiking by the Fed and rising fears of recession weighed on credit-sentiment.

The Trust’s exposures to cable and satellite, technology, healthcare and midstream energy sectors were the largest absolute detractors from performance. From a credit quality perspective, consistent with the broad market downturn during the reporting period, holdings of bonds in the BB, B and CCC ratings categories all detracted from return for the period.

From a sector perspective, independent energy, aerospace/defense and oil field services were the largest absolute contributors over the period. From an asset allocation perspective, the Trust’s currency positioning and stance with respect to interest rates were the most meaningful contributors.

The Trust’s practice of maintaining a specified level of monthly distributions to shareholders did not have a material impact on the Trust’s investment strategy. The distribution policy resulted in return of capital for the period. Refer to the financial highlights and income tax information sections in this report for further information about the distributions.

Describe recent portfolio activity.

Throughout the reporting period the Trust utilized intercorrelated asset classes to capitalize on relative value opportunities. This is highlighted by positioning early in the period in floating rate loan interest that offered some insulation from central bank tightening given the floating rate nature of the asset class. Another example is the rotation into investment grade corporate credit early in the fourth quarter of 2022 to take advantage of depressed prices in the BBB segment of the market. In addition, the Trust further reduced its equity exposure, which had been used to generate significant performance from the energy sector in the first half of the year.

The Trust successfully completed a rights offering in October 2022, raising approximately $168 million and providing capital to take advantage of opportunities in the high yield market, including attractive high yield credit spreads and higher yield levels, to potentially enhance the Trust’s earnings and performance. BlackRock, not the Trust, covered all expenses of the offering and structured the offering to limit NAV dilution, which was $0.13 per share or approximately 1.4% of NAV.

From a ratings perspective, the Trust maintained an underweight to BB rated issues and overweights to Bs and CCCs throughout the period. However, importantly, the Trust avoided the highest yielding, distressed component of the CCC market. By sector, the Trust meaningfully decreased exposure to healthcare given strong headwinds for the space.

Describe portfolio positioning at period end.

The Trust was overweight issues rated B and CCC while avoiding distressed issues in the latter segment. The Trust was underweight in BB rated issues in favor of BBB issues based on relative value. Top sector overweights included technology, aerospace/defense and independent energy, while the biggest underweight was to healthcare.

The views expressed reflect the opinions of BlackRock as of the date of this report and are subject to change based on changes in market, economic or other conditions. These views are not intended to be a forecast of future events and are no guarantee of future results.

Overview of the Trust’s Total Investments

Investment Objective

BlackRock Credit Allocation Income Trust’s (BTZ) (the “Trust”) investment objective is to provide current income, current gains and capital appreciation. The Trust seeks to achieve its investment objective by investing, under normal market conditions, at least 80% of its assets in credit-related securities, including, but not limited to, investment grade corporate bonds, high yield bonds (commonly referred to as “junk” bonds), bank loans, preferred securities or convertible bonds or derivatives with economic characteristics similar to these credit-related securities. The Trust may invest directly in such securities or synthetically through the use of derivatives.

No assurance can be given that the Trust’s investment objective will be achieved.

Trust Information

Market Price and Net Asset Value Per Share Summary

GROWTH OF $10,000 INVESTMENT

Performance

Returns for the period ended December 31, 2022 were as follows:

Performance results may include adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles.

Past performance is not an indication of future results.

The Trust is presenting the performance of one or more indices for informational purposes only. The Trust is actively managed and does not seek to track or replicate the performance of any index. The index performance shown is not intended to be indicative of the Trust’s investment strategies, portfolio components or past or future performance.

More information about the Trust’s historical performance can be found in the “Closed End Funds” section of blackrock.com.

The following discussion relates to the Trust’s absolute performance based on NAV:

What factors influenced performance?

Risk assets sold off following persistently high inflation numbers, concerns around slowing economic growth, and interest rate hikes by central banks around the world. Exposure to U.S. investment grade corporate bonds was the largest detractor from the Trust’s performance for the period as the sector came under pressure amid rising interest rates. The Trust’s exposure to U.S. high yield corporate bonds, preferred securities (which share characteristics of both stocks and bonds), European corporate credit, Asian corporate credit, and emerging markets corporate credit also detracted from performance as the markets broadly experienced a challenging year.

Contributors to the Trust’s performance were limited over the period and were led by the Trust’s interest rate positioning and exposure to uniform mortgage-backed securities (“UMBS”) issued by Fannie Mae and Freddie Mac.

In addition to employing leverage, the Trust uses derivatives as part of its investment strategy, including forward contracts to hedge foreign currency exposure of non-U.S. positions back to U.S. dollars and interest rate futures to adjust duration positioning tactically as needed. The use of derivatives over the period marginally detracted from performance.

The Trust’s practice of maintaining a specified level of monthly distributions to shareholders did not have a material impact on the Trust’s investment strategy. The distribution policy resulted in return of capital for the period. Refer to the financial highlights and income tax information sections in this report for further information about the distributions.

Describe recent portfolio activity.

Over the period, the Trust increased its exposure to securitized products through UMBS and collateralized loan obligations (“CLOs”). The Trust also increased exposure to U.S. investment grade corporate bonds in seeking to increase its overall credit quality profile. The Trust’s use of leverage increased over the period.

Describe portfolio positioning at period end.

At period end, the Trust was positioning cautiously with a focus on utilizing credit selection to drive performance in the expectation that performance dispersion among securities will increase across asset classes, geographies and sectors. In this vein, the Trust held up-in-quality allocations through investment grade corporate bonds and higher quality CLOs.

The views expressed reflect the opinions of BlackRock as of the date of this report and are subject to change based on changes in market, economic or other conditions. These views are not intended to be a forecast of future events and are no guarantee of future results.

Overview of the Trust’s Total Investments

Investment Objective

BlackRock Floating Rate Income Trust’s (BGT) (the “Trust”) primary investment objective is to provide a high level of current income. The Trust’s secondary investment objective is to seek the preservation of capital to the extent consistent with its primary objective of high current income. The Trust seeks to achieve its investment objectives by investing primarily, under normal conditions, at least 80% of its assets in floating and variable rate instruments of U.S. and non-U.S. issuers, including a substantial portion of its assets in global floating and variable rate securities including senior secured floating rate loans made to corporate and other business entities. Under normal market conditions, the Trust expects that the average effective duration of its portfolio will be no more than 1.5 years. The Trust may invest directly in such securities or synthetically through the use of derivatives.

No assurance can be given that the Trust’s investment objective will be achieved.

Trust Information

Market Price and Net Asset Value Per Share Summary

GROWTH OF $10,000 INVESTMENT

Performance

Returns for the period ended December 31, 2022 were as follows:

Performance results may include adjustments made for financial reporting purposes in accordance with U.S. generally accepted accounting principles. Past performance is not an indication of future results.

The Trust is presenting the performance of one or more indices for informational purposes only. The Trust is actively managed and does not seek to track or replicate the performance of any index. The index performance shown is not intended to be indicative of the Trust’s investment strategies, portfolio components or past or future performance.

More information about the Trust’s historical performance can be found in the “Closed End Funds” section of blackrock.com.

The following discussion relates to the Trust’s absolute performance based on NAV:

What factors influenced performance?

Bank loans delivered modestly negative performance in 2022 amid a broader downturn across markets, but they outpaced most major fixed-income categories. At a time of high inflation and rising interest rates, loans’ floating-rate feature fueled elevated investor demand in the first half of the year, though this subsided into the 3rd and 4th quarters.

From a sector perspective, the Trust’s holdings in property and casualty, airlines, automotive and chemicals were the largest contributors.

Conversely, positions in the healthcare, wireline telecommunications, leisure and consumer products sectors detracted.

In terms of rating class, holdings in the BB and BBB rated categories produced the best results. Lower-quality CCC rated securities detracted, which was consistent with the broader “risk-off” sentiment in the market. The Trust’s out-of-benchmark allocation to high yield bonds, while limited, was a further detractor given underperformance of the high yield market relative to Loans.

The Trust’s practice of maintaining a specified level of monthly distributions to shareholders did not have a material impact on the Trust’s investment strategy. The distribution policy did not result in return of capital for the period. Refer to the financial highlights and income tax information sections in this report for further information about the distributions.

Describe recent portfolio activity.

The investment adviser managed the Trust’s asset allocation and leverage levels throughout the period based on market views, borrowing costs, and income generation considerations. It took down the Trust’s allocations to B and CCC rated issues in an effort to reduce risk, but it maintained overweights in both areas. It kept the weighting in BB rated debt largely unchanged.

The Trust further decreased its allocations to the technology and healthcare sectors. However, the investment adviser continued to believe bottom-up security selection is the most important driver of performance. The Trust continued to use liquid, index-based derivatives in the loan and high-yield markets to manage its positioning.

Describe portfolio positioning at period end.

Consistent with its core investment strategy, the Trust remained predominately invested in bank loans with a weighting of over 95% of assets held in the category. The rest of the portfolio was allocated to high yield bonds and cash.

B rated loans were the Trust’s largest allocation by credit rating. Within the category, the adviser remained highly selective with respect to B3 rated issues given the higher risk of downgrades at a time of slowing economic growth. In the CCC space, it focused on avoiding the lowest-quality segments of the market.

Although the investment adviser reduced the Trust’s positions in the technology and healthcare sectors, they still represent fairly large allocations in the portfolio given their respective weightings in the index. In general, the Trust’s sector composition is a byproduct of individual security selection.

The investment adviser had a bias toward larger loan tranches of $1 billion and above, and it maintained a preference for loan/bond capital structures over the loan-only segment.

The views expressed reflect the opinions of BlackRock as of the date of this report and are subject to change based on changes in market, economic or other conditions. These views are not intended to be a forecast of future events and are no guarantee of future results.

Overview of the Trust’s Total Investments