Primary Offering Prospectus (Form 424B2)

This term sheet, which is not complete and may be changed, relates to an effective Registration Statement under the Securities Act of 1933. This term sheet and the accompanying product supplement, prospectus supplement and prospectus are not an offer to sell these notes in any country or jurisdiction where such an offer would not be permitted.

The notes are being issued by BofA Finance LLC ("BofA Finance") and are fully and unconditionally guaranteed by Bank of America Corporation ("BAC"). There are important differences between the notes and a conventional debt security, including different investment risks and certain additional costs. See "Risk Factors" beginning on page TS-6 of this term sheet, "Additional Risk Factors" on page TS-7 of this term sheet and "Risk Factors" beginning on page PS-6 of the accompanying product supplement, page S-6 of the accompanying Series A MTN prospectus supplement and page 7 of the accompanying prospectus.

The initial estimated value of the notes as of the pricing date is expected to be between $9.35 and $9.85 per unit, which is less than the public offering price listed below. See "Summary" on the following page, "Risk Factors" beginning on page TS-6 of this term sheet and "Structuring the Notes" on page TS-12 of this term sheet for additional information. The actual value of your notes at any time will reflect many factors and cannot be predicted with accuracy.

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None of the Securities and Exchange Commission (the "SEC"), any state securities commission, or any other regulatory body has approved or disapproved of these securities or determined if this Note Prospectus (as defined below) is truthful or complete. Any representation to the contrary is a criminal offense.

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The notes and the related guarantee:

BofA Securities

October , 2025

Summary

The Market-Linked One Look Barrier Notes Linked to the KraneShares CSI China Internet ETF, due January , 2027 (the "notes") are our senior unsecured debt securities. Payments on the notes are fully and unconditionally guaranteed by BAC. The notes and the related guarantee are not insured by the Federal Deposit Insurance Corporation or secured by collateral. The notes will rank equally in right of payment with all of BofA Finance's other unsecured and unsubordinated obligations, except obligations that are subject to any priorities or preferences by law. The related guarantee will rank equally in right of payment with all of BAC's other unsecured and unsubordinated obligations, except obligations that are subject to any priorities or preferences by law, and senior to its subordinated obligations. Any payments due on the notes, including any repayment of principal, will be subject to the credit risk of BofA Finance, as issuer, and BAC, as guarantor. The notes provide you with a Digital Payment if the Ending Value of the Underlying Fund, which is the KraneShares CSI China Internet ETF (the "Underlying Fund"), is equal to or greater than the Threshold Value. If the Ending Value is less than the Threshold Value, you will lose all or a portion of the principal amount of your notes. Any payments on the notes will be calculated based on the $10 principal amount per unit and will depend on the performance of the Underlying Fund, subject to our and BAC's credit risk. See "Terms of the Notes" below.

The economic terms of the notes (including the Digital Payment) are based on BAC's internal funding rate, which is the rate it would pay to borrow funds through the issuance of market-linked notes and the economic terms of certain related hedging arrangements. BAC's internal funding rate is typically lower than the rate it would pay when it issues conventional fixed or floating rate debt securities. This difference in funding rate, as well as the underwriting discount and costs associated with hedging the notes, will reduce the economic terms of the notes to you and the initial estimated value of the notes on the pricing date. Due to these factors, the public offering price you pay to purchase the notes will be greater than the initial estimated value of the notes.

On the cover page of this term sheet, we have provided the initial estimated value range for the notes. This initial estimated value range was determined based on our, BAC's and our other affiliates' pricing models, which take into consideration BAC's internal funding rate and the market prices for the hedging arrangements related to the notes. The initial estimated value is based on an assumed tenor of the notes. The initial estimated value of the notes calculated on the pricing date will be set forth in the final term sheet made available to investors in the notes. For more information about the initial estimated value and the structuring of the notes, see "Structuring the Notes" on page TS-12.

The terms and risks of the notes are contained in this term sheet and in the following:

These documents (together, the "Note Prospectus") have been filed as part of a registration statement with the SEC, which may, without cost, be accessed on the SEC website as indicated above or obtained from Merrill Lynch, Pierce, Fenner & Smith Incorporated ("MLPF&S") or BofAS by calling 1-800-294-1322. Before you invest, you should read the Note Prospectus, including this term sheet, for information about us, BAC and this offering. Any prior or contemporaneous oral statements and any other written materials you may have received are superseded by the Note Prospectus. Certain terms used but not defined in this term sheet have the meanings set forth in the accompanying product supplement. Unless otherwise indicated or unless the context requires otherwise, all references in this document to "we," "us," "our," or similar references are to BofA Finance, and not to BAC.

Investor Considerations

We urge you to consult your investment, legal, tax, accounting, and other advisors before you invest in the notes.

Hypothetical Payout Profile and Examples of Payments at Maturity

The following table and examples are for purposes of illustration only. They are based on hypothetical values and show hypothetical returns on the notes. They illustrate the calculation of the Redemption Amount and total rate of return based on a hypothetical Starting Value of 100, a hypothetical Threshold Value of 80.00, a hypothetical Digital Payment of $2.00 per unit (the midpoint of the Digital Payment range of [$1.90 to $2.10]) and a range of hypothetical Ending Values. The actual amount you receive and the resulting total rate of return will depend on the actual Starting Value, Threshold Value, Ending Value and Digital Payment, and whether you hold the notes until maturity. The following examples do not take into account any tax consequences from investing in the notes.

For recent actual prices of the Market Measure, see "The Underlying Fund" section below. All payments on the notes are subject to issuer and guarantor credit risk.

Redemption Amount Calculation Examples

In this example, even though the Ending Value is significantly greater than both the Threshold Value and the Starting Value, your return on the notes will be limited to the return represented by the Digital Payment.

Risk Factors

There are important differences between the notes and a conventional debt security. An investment in the notes involves significant risks, including those listed below. You should carefully review the more detailed explanation of risks relating to the notes in the "Risk Factors" sections beginning on page PS-6 of the accompanying product supplement, page S-6 of the Series A MTN prospectus supplement, and page 7 of the prospectus identified above. We also urge you to consult your investment, legal, tax, accounting, and other advisors before you invest in the notes.

Structure-related Risks

Valuation- and Market-related Risks

Conflict-related Risks

Market Measure-related Risks

Tax-related Risks

Additional Risk Factors
Adverse conditions in the internet sector may reduce your return on the notes.

All of the stocks held by the Underlying Fund are issued by companies whose primary lines of business are directly associated with the internet sector. Internet companies are subject to intense competition, the risk of product obsolescence, changes in consumer preferences and legal, regulatory and political changes. Internet companies are also especially at risk of hacking and other cybersecurity events. In addition, it can be difficult to determine what qualifies as an internet company. Any adverse developments affecting the internet sector could adversely affect the price of the Underlying Fund and, in turn, the value of the notes.

The Underlying Fund is subject to concentrated risks associated with the internet sector in China.

The securities held by the Underlying Fund are concentrated in China-based companies whose primary business or businesses are in the internet and internet-related sectors. Companies in these sectors are subject to concentrated risks, including risks of changes in technology, the competitive environment and government regulation. The underlying shares of the Underlying Fund may be more volatile and be more adversely affected by a single negative economic, political or regulatory occurrence affecting the internet and internet-related sectors in China than a different investment in a more broadly diversified group of industries.

The notes are subject to risks associated with foreign securities markets.

The Underlying Fund holds certain foreign equity securities. You should be aware that investments in securities linked to the value of foreign equity securities involve particular risks. The foreign securities markets comprising the Underlying Fund may have less liquidity and may be more volatile than U.S. or other securities markets and market developments may affect foreign markets differently from U.S. or other securities markets. Direct or indirect government intervention to stabilize these foreign securities markets, as well as cross-shareholdings in foreign companies, may affect trading prices and volumes in these markets. Also, there is generally less publicly available information about foreign companies than about those U.S. companies that are subject to the reporting requirements of the SEC, and foreign companies are subject to accounting, auditing and financial reporting standards and requirements that differ from those applicable to U.S. reporting companies.

Prices of securities in foreign countries are subject to political, economic, financial and social factors that apply in those geographical regions. These factors, which could negatively affect those securities markets, include the possibility of recent or future changes in a foreign government's economic and fiscal policies, the possible imposition of, or changes in, currency exchange laws or other laws or restrictions applicable to foreign companies or investments in foreign equity securities and the possibility of fluctuations in the rate of exchange between currencies, the possibility of outbreaks of hostility and political instability and the possibility of natural disaster or adverse public health developments in the region. Moreover, foreign economies may differ favorably or unfavorably from the U.S. economy in important respects such as growth of gross national product, rate of inflation, capital reinvestment, resources and self-sufficiency.

The stocks held by the Underlying Fund are concentrated in one sector.

The Underlying Fund holds securities issued by companies in the internet sector. As a result, some of the stocks that will determine the performance of the notes are concentrated in one sector. Although an investment in the notes will not give holders any ownership or other direct interests in the securities held by the Underlying Fund, the return on an investment in the notes will be subject to certain risks associated with a direct equity investment in companies in this sector. Accordingly, by investing in the notes, you will not benefit from the diversification which could result from an investment linked to companies that operate in multiple sectors.

Recent executive orders may adversely affect the performance of the Underlying Fund.

Pursuant to recent executive orders, U.S. persons are prohibited from engaging in transactions in, or possession of, publicly traded securities of certain companies that are determined to be linked to the People's Republic of China military, intelligence and security apparatus, or securities that are derivative of, or are designed to provide investment exposure to, those securities. If the issuer of any of the equity securities held by the Underlying Fund is in the future designated as such a prohibited company, the value of that company may be adversely affected, perhaps significantly, which would adversely affect the performance of the Underlying Fund. In addition, under these circumstances, the Underlying Fund is expected to remove the equity securities of that company from the Underlying Fund. Any changes to the composition of the Underlying Fund in response to these executive orders could adversely affect the performance of the Underlying Fund.

There are risks associated with emerging markets.

An investment in the notes will involve risks not generally associated with investments which have no emerging market component. In particular, many emerging nations are undergoing rapid change, involving the restructuring of economic, political, financial and legal systems. Regulatory and tax environments may be subject to change without review or appeal. Many emerging markets suffer from underdevelopment of capital markets and tax regulation. The risk of expropriation and nationalization remains a threat. Guarding against such risks is made more difficult by low levels of corporate disclosure and unreliability of economic and financial data.

The Underlying Fund

All disclosures contained in this term sheet regarding the Underlying Fund, including, without limitation, its make-up, method of calculation, and changes in its components, have been derived from publicly available sources. The information reflects the policies of, and is subject to change by, Krane Funds Advisors, LLC ("Krane"), the advisor to the Underlying Fund. The advisor, which licenses the copyright and all other rights to the Underlying Fund, has no obligation to continue to publish, and may discontinue publication of, the Underlying Fund. The consequences of the advisor discontinuing publication of the Underlying Fund are discussed in the section entitled "Description of the Notes - Anti-Dilution and Discontinuance Adjustments Relating to Underlying Funds-Discontinuance of or Material Change to an Underlying Fund" beginning on page PS-39 of the accompanying product supplement. None of us, BAC, the calculation agent, MLPF&S or BofAS accepts any responsibility for the calculation, maintenance, or publication of the Underlying Fund or any successor underlying fund.

The KraneShares CSI China Internet ETF

The Underlying Fund is an investment portfolio managed by KraneShares Trust (the "Trust"), a registered investment company, and Krane, the investment adviser of the Underlying Fund. The shares of the Underlying Fund trade on the NYSE under ticker symbol "KWEB."

Information provided to or filed with the SEC by pursuant to the Securities Act of 1933, as amended, and the Investment Company Act of 1940, as amended, can be located by reference to SEC file numbers 333-180870 and 811-22698, respectively, through the SEC's website at http://www.sec.gov. In addition, information may be obtained from other sources including, but not limited to, press releases, newspaper articles and other publicly disseminated documents.

Investment Objective and Strategy

The Underlying Fund seeks to track the investment results, before fees and expenses, of the CSI Overseas China Internet Index, a free float market capitalization weighted index consisting of China based companies whose primary business or businesses are in the Internet and Internet-related sectors and are listed outside of Mainland China. Under normal circumstances, the Underlying Fund will invest at least 80% of its total assets in components of its underlying index and in depositary receipts representing securities in its underlying index. The Underlying Fund uses a representative sampling strategy to try to track the CSI Overseas China Internet Index. The returns of the Underlying Fund may be affected by certain management fees and other expenses, which are detailed in its prospectus.

Description of the CSI Overseas China Internet Index

The underlying index is designed to measure the performance of publicly traded China-based companies whose primary business or businesses are in the internet and internet-related sectors (together, "China Internet Companies"), and are listed outside of Mainland China, as determined by China Securities Index Co., Ltd. (the "underlying index sponsor"). The underlying index sponsor treats China-based companies as including companies that (i) are incorporated in mainland China, (ii) have their headquarters in mainland China, or (iii) derive at least 50% of their revenue from goods produced or sold, or services performed, in mainland China. The underlying index sponsor then removes all securities that had a daily average trading volume of less than $1 million or a daily average market capitalization of less than $1 billion, each measured during the prior year. China Internet Companies include, but are not limited to, companies that develop and market internet software and/or provide internet services, manufacture home entertainment software and educational software for home use; provide retail or commercial services primarily through the internet; and develop and market mobile Internet software and/or provide mobile Internet services. Constituents of the underlying index are ranked by market capitalization in U.S. dollars and then weighted so that no constituent weighted exceeds 10% at each rebalance.

The following graph shows the daily historical performance of the Underlying Fund in the period from January 1, 2015through October 15, 2025. We obtained this historical data from Bloomberg L.P. We have not independently verified the accuracy or completeness of the information obtained from Bloomberg L.P. OnOctober 15, 2025, the Closing Market Price of theUnderlying Fund was $39.66.

Historical Performance of the Underlying Fund

This historical data on the Underlying Fundis not necessarily indicative of the future performance of the Underlying Fundor what the value of the notes may be. Any historical upward or downward trend in the price of the Underlying Fundduring any period set forth above is not an indication that the price of the Underlying Fund is more or less likely to increase or decrease at any time over the term of the notes.

Before investing in the notes, you should consult publicly available sources for the prices and trading pattern of the Underlying Fund.

Supplement to the Plan of Distribution; Conflicts of Interest

Under our distribution agreement with BofAS, BofAS will purchase the notes from us as principal at the public offering price indicated on the cover of this term sheet, less the indicated underwriting discount.

MLPF&S will purchase the notes from BofAS for resale, and will receive a discount in connection with the sale of the notes in an amount up to the full amount of underwriting discount set forth on the cover of this term sheet.

We will pay a fee to LFT Securities, LLC for providing certain electronic platform services with respect to this offering, which will reduce the economic terms of the Notes to you. An affiliate of BofAS has an ownership interest in LFT Securities, LLC.

MLPF&S and BofAS, each a broker-dealer subsidiary of BAC, are members of the Financial Industry Regulatory Authority, Inc. ("FINRA") and will participate as selling agent in the case of BofAS and as dealer in the case of MLPF&S in the distribution of the notes. Accordingly, offerings of the notes will conform to the requirements of Rule 5121 applicable to FINRA members. Neither BofAS nor MLPF&S may make sales in this offering to any of its discretionary accounts without the prior written approval of the account holder.

We may deliver the notes against payment therefor in New York, New York on a date that is greater than one business day following the pricing date. Under Rule 15c6-1 of the Securities Exchange Act of 1934, as amended, trades in the secondary market generally are required to settle in one business day, unless the parties to any such trade expressly agree otherwise. Accordingly, if the initial settlement of the notes occurs more than one business day from the pricing date, purchasers who wish to trade the notes more than one business day prior to the original issue date will be required to specify alternative settlement arrangements to prevent a failed settlement.

The notes will not be listed on any securities exchange. In the original offering of the notes, the notes will be sold in minimum investment amounts of 10,000 units. If you place an order to purchase the notes, you are consenting to MLPF&S and/or one of its affiliates acting as a principal in effecting the transaction for your account.

MLPF&S and BofAS may repurchase and resell the notes, with repurchases and resales being made at prices related to then-prevailing market prices or at negotiated prices, and these will include MLPF&S's and BofAS's trading commissions and mark-ups or mark-downs. MLPF&S and BofAS may act as principal or agent in these market-making transactions; however, neither is obligated to engage in any such transactions. At their discretion, for a short, undetermined initial period after the issuance of the notes, MLPF&S and BofAS may offer to buy the notes in the secondary market at a price that may exceed the initial estimated value of the notes. Any price offered by MLPF&S or BofAS for the notes will be based on then-prevailing market conditions and other considerations, including the performance of the Underlying Fund and the remaining term of the notes. However, neither we nor any of our affiliates is obligated to purchase your notes at any price, or at any time, and we cannot assure you that we or any of our affiliates will purchase your notes at a price that equals or exceeds the initial estimated value of the notes.

The value of the notes shown on your account statement will be based on BofAS's estimate of the value of the notes if BofAS or another of our affiliates were to make a market in the notes, which it is not obligated to do. That estimate will be based upon the price that BofAS may pay for the notes in light of then-prevailing market conditions and other considerations, as mentioned above, and will include transaction costs. At certain times, this price may be higher than or lower than the initial estimated value of the notes.

Structuring the Notes

The notes are our debt securities, the return on which is linked to the performance of the Underlying Fund. The related guarantees are BAC's obligations. As is the case for all of our and BAC's respective debt securities, including our market-linked notes, the economic terms of the notes reflect our and BAC's actual or perceived creditworthiness at the time of pricing. In addition, because market-linked notes result in increased operational, funding and liability management costs to us and BAC, BAC typically borrows the funds under these types of notes at a rate that is more favorable to BAC than the rate that it might pay for a conventional fixed or floating rate debt security. This rate, which we refer to in this term sheet as BAC's internal funding rate, is typically lower than the rate BAC would pay when it issues conventional fixed or floating rate debt securities. This generally relatively lower internal funding rate, which is reflected in the economic terms of the notes, along with the fees and charges associated with market-linked notes, typically results in the initial estimated value of the notes on the pricing date being less than their public offering price.

At maturity, we are required to pay the Redemption Amount to holders of the notes, which will be calculated based on the performance of the Underlying Fund and the $10 per unit principal amount. In order to meet these payment obligations, at the time we issue the notes, we may choose to enter into certain hedging arrangements (which may include call options, put options or other derivatives) with BofAS or one of our other affiliates. The terms of these hedging arrangements are determined by seeking bids from market participants, including MLPF&S, BofAS and its affiliates, and take into account a number of factors, including our and BAC's creditworthiness, interest rate movements, the volatility of the Underlying Fund, the tenor of the notes and the tenor of the hedging arrangements. The economic terms of the notes and their initial estimated value depend in part on the terms of these hedging arrangements. These hedging arrangements are expected to result in a profit to those engaging in the hedging activity, which could be more or less than initially expected, but could also result in a loss.

For further information, see "Risk Factors" beginning on page PS-6 and "Use of Proceeds" on page PS-27 of the accompanying product supplement.

Summary Tax Consequences

You should consider the U.S. federal income tax consequences of an investment in the notes, including the following:

You should consult your own tax advisor concerning the U.S. federal income tax consequences to you of acquiring, owning, and disposing of the notes, as well as any tax consequences arising under the laws of any state, local, foreign, or other tax jurisdiction and the possible effects of changes in U.S. federal or other tax laws. You should review carefully the discussion under the section entitled "U.S. Federal Income Tax Summary" beginning on page PS-53 of the accompanying product supplement.

Where You Can Find More Information

We and BAC have filed a registration statement (including a product supplement, a prospectus supplement, and a prospectus) with the SEC for the offering to which this term sheet relates. Before you invest, you should read the Note Prospectus, including this term sheet, and the other documents relating to this offering that we and BAC have filed with the SEC, for more complete information about us, BAC and this offering. You may get these documents without cost by visiting EDGAR on the SEC website at www.sec.gov. Alternatively, we, any agent, or any dealer participating in this offering will arrange to send you these documents if you so request by calling MLPF&S or BofAS toll-free at 1-800-294-1322.