FEBRUARY 26, 2021

Summary Prospectus

BlackRock Liquidity Funds  |  Private Client Shares

• MuniFund

Private Client: BMPXX

Before you invest, you may want to review the Fund’s prospectus, which contains more information about the Fund and its risks. You can find the Fund’s prospectus (including amendments and supplements), reports to shareholders and other information about the Fund, including the Fund’s statement of additional information, online at http://www.blackrock.com/prospectus/cash. You can also get this information at no cost by calling (800) 441-7450 or by sending an  e-mail request to prospectus.request@blackrock.com, or from your financial professional. The Fund’s prospectus and statement of additional information, both dated February 26, 2021, as amended and supplemented from time to time, are incorporated by reference into (legally made a part of) this Summary Prospectus.

This Summary Prospectus contains information you should know before investing, including information about risks. Please read it before you invest and keep it for future reference.

The Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this Summary Prospectus. Any representation to the contrary is a criminal offense.

Not FDIC Insured • May Lose Value • No Bank Guarantee

Summary Prospectus

Key Facts About MuniFund

Investment Objective

The investment objective of MuniFund (the “Fund”), a series of BlackRock Liquidity Funds (the “Trust”), is to seek as high a level of current income exempt from federal income tax as is consistent with liquidity and stability of principal.

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy, hold and sell Private Client Shares of MuniFund. You may pay other fees, such as brokerage commissions and other fees to your financial professional or your selected securities dealer, broker, investment adviser, service provider or industry professional (including BlackRock Advisors, LLC (“BlackRock”) and its affiliates) (each, a “Financial Intermediary”), which are not reflected in the table and example below.

Annual Fund Operating Expenses

(expenses that you pay each year as a percentage of the value of your investment)

	Private Client Shares
Management Fee	0.35%
Distribution (12b-1) Fees	0.35%
Other Expenses	0.74%
Shareholder Servicing Fees	0.50%
Miscellaneous/Other Expenses	0.24%
Total Annual Fund Operating Expenses	1.44%
Fee Waivers and/or Expense Reimbursements1,2	(0.76)%
Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements1,2	0.68%

¹  As described in the “Management of the Funds” section of the Fund’s prospectus beginning on page 56, BlackRock, the Fund’s investment manager, has contractually agreed to waive fees and/or reimburse ordinary operating expenses in order to keep combined Management Fees and Miscellaneous/Other Expenses (excluding Dividend Expense, Interest Expense, Acquired Fund Fees and Expenses and certain other Fund expenses) from exceeding 0.20% of average daily net assets through February 28, 2022. The agreement may be terminated upon 90 days’ notice by a majority of the non-interested trustees of the Trust or by a vote of a majority of the outstanding voting securities of the Fund.

²  As described in the “Management of the Funds” section of the Fund’s prospectus beginning on page 56, the Fund’s distributor and the Financial Intermediary party to the waiver agreement have contractually agreed to waive Distribution Fees and/or Shareholder Servicing Fees so that the Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements of the Private Client Shares do not exceed 0.68% of average daily net assets through February 28, 2022. The agreement renews automatically for successive one year periods and may be terminated by any party upon written notice 75 days prior to the commencement of a successive one year period.

Example:

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

	1 Year	3 Years	5 Years	10 Years
Private Client Shares	$69	$381	$714	$1,659

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Principal Investment Strategies of the Fund

Under normal circumstances, MuniFund invests: (i) at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in a broad range of short-term obligations issued by or on behalf of states, territories and possessions of the United States, the District of Columbia, and their respective authorities, agencies, instrumentalities and political subdivisions and derivative securities, such as beneficial interests in municipal trust certificates and partnership trusts (“Municipal Obligations”), the interest on which, in the opinion of counsel to the issuer of the obligation, is exempt from regular federal income tax; or (ii) so that at least 80% of the income distributed by the Fund will be exempt from regular federal income tax. Municipal Obligations in which the Fund may invest will also not be subject to the federal alternative minimum tax. The Fund invests in securities maturing in 397 days or less (with certain exceptions) and the portfolio will have a dollar-weighted average maturity of 60 days or less and a dollar-weighted average life of 120 days or less. The Fund may also invest in variable and floating rate instruments, and transact in securities on a when-issued, delayed delivery or forward commitment basis.

The securities purchased by the Fund are subject to the quality, diversification, and other requirements of Rule 2a-7 under the Investment Company Act of 1940, as amended (the “1940 Act”), and other rules of the Securities and Exchange Commission. The Fund will only purchase securities that present minimal credit risk as determined by BlackRock, the Fund’s investment manager, pursuant to guidelines approved by the Trust’s Board of Trustees (the “Board”).

Principal Risks of Investing in the Fund

Risk is inherent in all investing. You could lose money by investing in the Fund. Although the Fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. The Fund may impose a fee upon the sale of your shares or may temporarily suspend your ability to sell shares if the Fund’s liquidity falls below required minimums because of market conditions or other factors. An investment in the Fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The Fund’s sponsor has no legal obligation to provide financial support to the Fund, and you should not expect that the sponsor will provide financial support to the Fund at any time.

The following is a summary description of principal risks of investing in the Fund. The order of the below risk factors does not indicate the significance of any particular risk factor.

◾ Credit Risk — Credit risk refers to the possibility that the issuer of a debt security (i.e., the borrower) will not be able to make payments of interest and principal when due. Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the value of the Fund’s investment in that issuer.

◾ Foreign Exposure Risk — Securities issued or supported by foreign entities, including foreign banks and corporations, may involve additional risks and considerations. Extensive public information about the foreign issuer may not be available, and unfavorable political, economic or governmental developments in the foreign country involved could affect the payment of principal and interest.

◾ Income Risk — Income risk is the risk that the Fund’s yield will vary as short-term securities in its portfolio mature and the proceeds are reinvested in securities with different interest rates.

◾ Interest Rate Risk — Interest rate risk is the risk that the value of a debt security may fall when interest rates rise. In general, the market price of debt securities with longer maturities will go up or down more in response to changes in interest rates than the market price of shorter-term securities. Due to fluctuations in interest rates, the market value of such securities may vary during the period shareholders own shares of the Fund. Very low or negative interest rates may magnify interest rate risk. During periods of very low or negative interest rates, the Fund may be unable to maintain positive returns or pay dividends to Fund shareholders. Changing interest rates, including rates that fall below zero, may have unpredictable effects on markets, may result in heightened market volatility and may detract from the Fund’s ability to achieve its investment objective.

◾ Liquidity Fee and Redemption Gate Risk — The Board has discretion to impose a liquidity fee of up to 2% upon sale of your shares or may temporarily suspend your ability to sell shares if the Fund’s liquidity falls below required minimums because of market conditions or other factors. Accordingly, you may not be able to sell your shares or your redemptions may be subject to a liquidity fee when you sell your shares at certain times.

◾ Market Risk and Selection Risk — Market risk is the risk that one or more markets in which the Fund invests will go down in value, including the possibility that the markets will go down sharply and unpredictably. The value of a security or other

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asset may decline due to changes in general market conditions, economic trends or events that are not specifically related to the issuer of the security or other asset, or factors that affect a particular issuer or issuers, exchange, country, group of countries, region, market, industry, group of industries, sector or asset class. Local, regional or global events such as war, acts of terrorism, the spread of infectious illness or other public health issues like pandemics or epidemics, recessions, or other events could have a significant impact on the Fund and its investments. Selection risk is the risk that the securities selected by Fund management will underperform the markets, the relevant indices or the securities selected by other funds with similar investment objectives and investment strategies. This means you may lose money.

A recent outbreak of an infectious coronavirus has developed into a global pandemic that has resulted in numerous disruptions in the market and has had significant economic impact leaving general concern and uncertainty. Because the Fund invests in short-term instruments these events have caused some instruments to have declining yields, which may impair the results of the Fund if these conditions persisted. The impact of this coronavirus, and other epidemics and pandemics that may arise in the future, could affect the economies of many nations, individual companies and the market in general ways that cannot necessarily be foreseen at the present time.

◾ Municipal Securities Concentration Risk — From time to time the Fund may invest a substantial amount of its assets in municipal securities whose interest is paid solely from revenues of similar projects. If the Fund concentrates its investments in this manner, it assumes the legal and economic risks relating to such projects and this may have a significant impact on the Fund’s investment performance.

◾ Municipal Securities Risks — Municipal securities risks include the ability of the issuer to repay the obligation, the relative lack of information about certain issuers of municipal securities, and the possibility of future legislative changes which could affect the market for and value of municipal securities. These risks include:

General Obligation Bonds Risks — Timely payments depend on the issuer’s credit quality, ability to raise tax revenues and ability to maintain an adequate tax base.

Revenue Bonds Risks — These payments depend on the money earned by the particular facility or class of facilities, or the amount of revenues derived from another source.

Private Activity Bonds Risks — Municipalities and other public authorities issue private activity bonds to finance development of industrial facilities for use by a private enterprise. The private enterprise pays the principal and interest on the bond, and the issuer does not pledge its faith, credit and taxing power for repayment.

Moral Obligation Bonds Risks — Moral obligation bonds are generally issued by special purpose public authorities of a state or municipality. If the issuer is unable to meet its obligations, repayment of these bonds becomes a moral commitment, but not a legal obligation, of the state or municipality.

Municipal Notes Risks — Municipal notes are shorter term municipal debt obligations. If there is a shortfall in the anticipated proceeds, the notes may not be fully repaid and the Fund may lose money.

Municipal Lease Obligations Risks — In a municipal lease obligation, the issuer agrees to make payments when due on the lease obligation. Although the issuer does not pledge its unlimited taxing power for payment of the lease obligation, the lease obligation is secured by the leased property.

Tax-Exempt Status Risk — The Fund and its investment manager will rely on the opinion of issuers’ bond counsel and, in the case of derivative securities, sponsors’ counsel, on the tax-exempt status of interest on municipal bonds and payments under derivative securities. Neither the Fund nor its investment manager will independently review the bases for those tax opinions, which may ultimately be determined to be incorrect and subject the Fund and its shareholders to substantial tax liabilities.

◾ Stable Net Asset Value Risk — The Fund may not be able to maintain a stable net asset value (“NAV”) of $1.00 per share at all times. If the Fund fails to maintain a stable NAV (or if there is a perceived threat of such a failure), the Fund, along with other money market funds, could be subject to increased redemption activity.

◾ Taxability Risk — Future laws, regulations, rulings or court decisions may cause interest on municipal securities to be subject, directly or indirectly, to U.S. federal income taxation, or currently exempt interest on state municipal securities to be subject to state or local income taxation, or the value of state municipal securities that are currently exempt to be subject to state or local intangible personal property tax, or may otherwise prevent the Fund from realizing the full current benefit of the tax-exempt status of such securities. Any such change could also affect the market price of such securities, and thus the value of an investment in the Fund.

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◾ Treasury Obligations Risk — Direct obligations of the U.S. Treasury have historically involved little risk of loss of principal if held to maturity. However, due to fluctuations in interest rates, the market value of such securities may vary during the period shareholders own shares of the Fund.

◾ U.S. Government Obligations Risk — Certain securities in which the Fund may invest, including securities issued by certain U.S. Government agencies and U.S. Government sponsored enterprises, are not guaranteed by the U.S. Government or supported by the full faith and credit of the United States.

◾ Variable and Floating Rate Instrument Risk — Variable and floating rate securities provide for periodic adjustment in the interest rate paid on the securities. Certain of these securities may be subject to greater illiquidity risk than other fixed income securities, meaning the absence of an active market for these securities could make it difficult for the Fund to dispose of them at any given time.

◾ When-Issued and Delayed Delivery Securities and Forward Commitments Risk — When-issued and delayed delivery securities and forward commitments involve the risk that the security the Fund buys will lose value prior to its delivery. There also is the risk that the security will not be issued or that the other party to the transaction will not meet its obligation. If this occurs, the Fund may lose both the investment opportunity for the assets it set aside to pay for the security and any gain in the security’s price.

Performance Information

The information shows you how MuniFund’s performance has varied year by year and provides some indication of the risks of investing in the Fund. As with all such investments, past performance is not an indication of future results. The table includes all applicable fees. If BlackRock and its affiliates had not waived or reimbursed certain Fund expenses during these periods, the Fund’s returns would have been lower. The Fund is a money market fund managed pursuant to the requirements of Rule 2a-7 under the 1940 Act. Updated information on the Fund’s performance can be obtained by visiting www.blackrock.com/cash or can be obtained by phone at (800) 441-7450.

MuniFund

Private Client Shares

ANNUAL TOTAL RETURNS

As of 12/31

During the ten-year period shown in the bar chart, the highest return for a quarter was 0.27% (quarter ended June 30, 2019) and the lowest return for a quarter was 0.00% (quarter ended September 30, 2020).

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For the periods ended 12/31/20

Average Annual Total Returns

	1 Year	5 Years	10 Years
MuniFund—Private Client Shares	0.40%	0.46%	0.24%
	7-Day Yield As of December 31, 2020
MuniFund—Private Client Shares	0.01%

Current Yield: You may obtain the Fund’s current 7-day yield by calling (800) 441-7450 or by visiting the Fund’s website at www.blackrock.com/cash.

Investment Manager

MuniFund’s investment manager is BlackRock Advisors, LLC (previously defined as “BlackRock”).

Purchase and Sale of Fund Shares

The Fund is a retail money market fund and is intended only for sale to beneficial owners who are natural persons.

You may purchase or sell shares without paying a sales charge. You may generally purchase or redeem shares of the Fund each day on which the New York Stock Exchange is open.

Purchase orders and redemption orders must be transmitted through a brokerage account (an “Account”) with your Financial Intermediary. You have until the close of the federal funds wire (normally 6:45 p.m. Eastern time) to get your purchase money in to the Fund or your purchase order may be cancelled.

The Financial Intermediary may impose minimum investment requirements for your Account. The Fund’s officers reserve the right to vary or waive any minimum and subsequent investment requirements.

Tax Information

MuniFund anticipates that substantially all of its income dividends will be “exempt-interest dividends,” which are generally exempt from regular federal income taxes.

Payments to Broker/Dealers and Other Financial Intermediaries

If you purchase shares of MuniFund through a Financial Intermediary, the Fund and BlackRock Investments, LLC, the Fund’s distributor, or its affiliates may pay the Financial Intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the Financial Intermediary and your individual financial professional to recommend the Fund over another investment.

Ask your individual financial professional or visit your Financial Intermediary’s website for more information.

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INVESTMENT COMPANY ACT FILE # 811-2354

SPRO-LIQ-MF-PC-0221