<SEC-DOCUMENT>0001214659-25-017695.txt : 20251205
<SEC-HEADER>0001214659-25-017695.hdr.sgml : 20251205
<ACCEPTANCE-DATETIME>20251205210104
ACCESSION NUMBER:		0001214659-25-017695
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20251203
FILED AS OF DATE:		20251205
DATE AS OF CHANGE:		20251205

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			LANSING WILLIAM J
		CENTRAL INDEX KEY:			0001074500
		STANDARD INDUSTRIAL CLASSIFICATION:	RETAIL-CATALOG & MAIL-ORDER HOUSES [5961]
		ORGANIZATION NAME:           	07 Trade & Services
		STATE OF INCORPORATION:			MN
		FISCAL YEAR END:			1228

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-11689
		FILM NUMBER:		251554436

	MAIL ADDRESS:	
		STREET 1:		FAIR ISAAC CORPORATION
		STREET 2:		5 WEST MENDENHALL, SUITE 105
		CITY:			BOZEMAN
		STATE:			MT
		ZIP:			59715

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FAIR ISAAC CORP
		CENTRAL INDEX KEY:			0000814547
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-BUSINESS SERVICES, NEC [7389]
		ORGANIZATION NAME:           	07 Trade & Services
		EIN:				941499887
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		5 WEST MENDENHALL
		STREET 2:		SUITES 105
		CITY:			BOZEMAN
		STATE:			MT
		ZIP:			59715
		BUSINESS PHONE:		(406) 982-7276

	MAIL ADDRESS:	
		STREET 1:		5 WEST MENDENHALL
		STREET 2:		SUITES 105
		CITY:			BOZEMAN
		STATE:			MT
		ZIP:			59715

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	FAIR ISAAC & COMPANY INC
		DATE OF NAME CHANGE:	19920703
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>marketforms-71434.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-12-03</periodOfReport>

    <issuer>
        <issuerCik>0000814547</issuerCik>
        <issuerName>FAIR ISAAC CORP</issuerName>
        <issuerTradingSymbol>FICO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001074500</rptOwnerCik>
            <rptOwnerName>LANSING WILLIAM J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>5 WEST MENDENHALL, SUITE 105</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BOZEMAN</rptOwnerCity>
            <rptOwnerState>MT</rptOwnerState>
            <rptOwnerZipCode>59715</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>true</isDirector>
            <isOfficer>true</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
            <officerTitle>President and CEO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Market Share Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2025-12-03</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>false</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>8390</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2025-12-09</value>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>8390</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Market Share Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2025-12-03</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>false</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5100</value>
                    <footnoteId id="F4"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2025-12-09</value>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>5100</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2818</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each earned market share unit represents a right to receive one share of Fair Isaac common stock contingent upon continued employment.</footnote>
        <footnote id="F2">On December 9, 2022, the reporting person was granted a target award of 12,585 market share units. The award vests in three equal annual installments from the grant date based on the Company's satisfaction of certain performance criteria for each of the performance periods ending November 30, 2023, 2024, 2025. The performance criteria for 2025 were met, resulting in the award of market share units being reported herein.</footnote>
        <footnote id="F3">No expiration date.</footnote>
        <footnote id="F4">On December 9, 2023, the reporting person was granted a target award of 8,455 market share units. The award vests in three equal annual installments from the grant date based on the Company's satisfaction of certain performance criteria for each of the performance periods ending November 30, 2024, 2025, 2026. The performance criteria for 2025 were met, resulting in the award of market share units being reported herein.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Carrie H. Darling, Attorney-in-fact</signatureName>
        <signatureDate>2025-12-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
