<SEC-DOCUMENT>0001987329-25-000003.txt : 20251002
<SEC-HEADER>0001987329-25-000003.hdr.sgml : 20251002
<ACCEPTANCE-DATETIME>20251002164315
ACCESSION NUMBER:		0001987329-25-000003
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20250930
FILED AS OF DATE:		20251002
DATE AS OF CHANGE:		20251002

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Yarkoni Charlotte
		CENTRAL INDEX KEY:			0001987329
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-38962
		FILM NUMBER:		251369987

	MAIL ADDRESS:	
		STREET 1:		600 N. VEL R. PHILLIPS AVENUE
		CITY:			MILWAUKEE
		STATE:			WI
		ZIP:			53203

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FISERV INC
		CENTRAL INDEX KEY:			0000798354
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-BUSINESS SERVICES, NEC [7389]
		ORGANIZATION NAME:           	07 Trade & Services
		EIN:				391506125
		STATE OF INCORPORATION:			WI
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		600 N. VEL R. PHILLIPS AVENUE
		CITY:			MILWAUKEE
		STATE:			WI
		ZIP:			53203
		BUSINESS PHONE:		2628795000

	MAIL ADDRESS:	
		STREET 1:		600 N. VEL R. PHILLIPS AVENUE
		CITY:			MILWAUKEE
		STATE:			WI
		ZIP:			53203
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wk-form4_1759437792.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-09-30</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000798354</issuerCik>
        <issuerName>FISERV INC</issuerName>
        <issuerTradingSymbol>FI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001987329</rptOwnerCik>
            <rptOwnerName>Yarkoni Charlotte</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>600 N. VEL R. PHILLIPS AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MILWAUKEE</rptOwnerCity>
            <rptOwnerState>WI</rptOwnerState>
            <rptOwnerZipCode>53203</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Deferred Compensation Notional Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2025-09-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>253</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>128.93</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>253</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1353</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">These deferred compensation notional units were allocated under the Fiserv, Inc. Non-Employee Director Deferred Compensation Plan (the &quot;Plan&quot;), under which director fees otherwise payable in cash may be deferred in exchange for the allocation of notional units under the Plan. This Form 4 reports the crediting of units under the Plan on September 30, 2025, in respect of $32,500 of deferred compensation. The number of notional units credited is calculated by dividing the amount of compensation that is deferred by the closing price of the company's common stock on the date of deferral, or last business day prior. On September 30, 2025, the closing price of Fiserv's common stock was $128.93 per share. Following cessation of the reporting person's service to the company, each notional unit will be settled in shares of Fiserv common stock on a one-for-one basis.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Eric C. Nelson (attorney-in-fact)</signatureName>
        <signatureDate>2025-10-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
