<SEC-DOCUMENT>0001214659-20-009835.txt : 20201123
<SEC-HEADER>0001214659-20-009835.hdr.sgml : 20201123
<ACCEPTANCE-DATETIME>20201123192337
ACCESSION NUMBER:		0001214659-20-009835
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20201119
FILED AS OF DATE:		20201123
DATE AS OF CHANGE:		20201123

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			DEAL RICHARD
		CENTRAL INDEX KEY:			0001205411

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-11689
		FILM NUMBER:		201339512

	MAIL ADDRESS:	
		STREET 1:		181 METRO DRIVE
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95110

ISSUER:		

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

	BUSINESS ADDRESS:	
		STREET 1:		181 METRO DRIVE
		STREET 2:		SUITE 700
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95110
		BUSINESS PHONE:		(408) 535-1500

	MAIL ADDRESS:	
		STREET 1:		181 METRO DRIVE
		STREET 2:		SUITE 700
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95110

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	FAIR ISAAC & COMPANY INC
		DATE OF NAME CHANGE:	19920703
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>marketforms-49972.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-11-19</periodOfReport>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001205411</rptOwnerCik>
            <rptOwnerName>DEAL RICHARD</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>181 METRO DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SAN JOSE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95110</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>false</isDirector>
            <isOfficer>true</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
            <officerTitle>Executive Vice President</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Performance Share Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2020-11-19</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>false</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5360</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2020-12-10</value>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F4"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>5360</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5360</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each earned performance share unit represents a right to receive one share of Fair Isaac common stock contingent upon continued employment.</footnote>
        <footnote id="F2">On November 19, 2020 the Leadership Development and Compensation Committee of the Board of Directors of Fair Isaac Corporation determined that the reporting person earned the number of performance share units reported on this Form 4 based on achievement of certain performance metrics.</footnote>
        <footnote id="F3">The performance share units vest in three equal annual installments commencing on this date and one share will be delivered to the reporting person for each vested unit as soon as practicable thereafter.</footnote>
        <footnote id="F4">No expiration date.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Carrie H. Darling, Attorney-in-fact</signatureName>
        <signatureDate>2020-11-23</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
