<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>3</documentType>
<periodOfReport>2003-10-08</periodOfReport>
    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000721773</issuerCik>
        <issuerName>ELECTRONIC CLEARING HOUSE INC</issuerName>
        <issuerTradingSymbol>ECHO</issuerTradingSymbol>
</issuer>
<reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001265815</rptOwnerCik>
            <rptOwnerName>HOOFRING STEVE</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>28001 DOROTHY DR.</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>AGOURA HILLS</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>91301</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>0</isDirector>
<isOfficer>1</isOfficer>
<isTenPercentOwner>0</isTenPercentOwner>
<isOther>0</isOther>
<officerTitle>Vice President</officerTitle>
<otherText></otherText>
</reportingOwnerRelationship>
</reportingOwner>
<nonDerivativeTable>
<nonDerivativeHolding>
<securityTitle>
<value>common</value>
</securityTitle>
<postTransactionAmounts>
<sharesOwnedFollowingTransaction>
<value>0</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value>
</directOrIndirectOwnership>
<natureOfOwnership>
<value></value>
</natureOfOwnership>
</ownershipNature>
</nonDerivativeHolding>
</nonDerivativeTable>
<derivativeTable>
<derivativeHolding>
<securityTitle>
<value>options</value>
</securityTitle>
<conversionOrExercisePrice>
<value>8.01</value>
</conversionOrExercisePrice>
<exerciseDate>
<value>2004-10-08</value>
</exerciseDate>
<expirationDate>
<value>2009-10-08</value>
</expirationDate>
<underlyingSecurity>
<underlyingSecurityTitle>
<value>common</value>
</underlyingSecurityTitle>
<underlyingSecurityShares>
<value>4000</value>
</underlyingSecurityShares>
</underlyingSecurity>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value>
</directOrIndirectOwnership>
<natureOfOwnership>
<value></value>
</natureOfOwnership>
</ownershipNature>
</derivativeHolding>
<derivativeHolding>
<securityTitle>
<value>options</value>
</securityTitle>
<conversionOrExercisePrice>
<value>8.01</value>
</conversionOrExercisePrice>
<exerciseDate>
<value>2005-10-08</value>
</exerciseDate>
<expirationDate>
<value>2010-10-08</value>
</expirationDate>
<underlyingSecurity>
<underlyingSecurityTitle>
<value>common</value>
</underlyingSecurityTitle>
<underlyingSecurityShares>
<value>4000</value>
</underlyingSecurityShares>
</underlyingSecurity>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value>
</directOrIndirectOwnership>
<natureOfOwnership>
<value></value>
</natureOfOwnership>
</ownershipNature>
</derivativeHolding>
<derivativeHolding>
<securityTitle>
<value>options</value>
</securityTitle>
<conversionOrExercisePrice>
<value>8.01</value>
</conversionOrExercisePrice>
<exerciseDate>
<value>2006-10-08</value>
</exerciseDate>
<expirationDate>
<value>2011-10-08</value>
</expirationDate>
<underlyingSecurity>
<underlyingSecurityTitle>
<value>common</value>
</underlyingSecurityTitle>
<underlyingSecurityShares>
<value>4000</value>
</underlyingSecurityShares>
</underlyingSecurity>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value>
</directOrIndirectOwnership>
<natureOfOwnership>
<value></value>
</natureOfOwnership>
</ownershipNature>
</derivativeHolding>
<derivativeHolding>
<securityTitle>
<value>options</value>
</securityTitle>
<conversionOrExercisePrice>
<value>8.01</value>
</conversionOrExercisePrice>
<exerciseDate>
<value>2007-10-08</value>
</exerciseDate>
<expirationDate>
<value>2012-10-08</value>
</expirationDate>
<underlyingSecurity>
<underlyingSecurityTitle>
<value>common</value>
</underlyingSecurityTitle>
<underlyingSecurityShares>
<value>4000</value>
</underlyingSecurityShares>
</underlyingSecurity>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value>
</directOrIndirectOwnership>
<natureOfOwnership>
<value></value>
</natureOfOwnership>
</ownershipNature>
</derivativeHolding>
<derivativeHolding>
<securityTitle>
<value>options</value>
</securityTitle>
<conversionOrExercisePrice>
<value>8.01</value>
</conversionOrExercisePrice>
<exerciseDate>
<value>2008-10-08</value>
</exerciseDate>
<expirationDate>
<value>2013-10-08</value>
</expirationDate>
<underlyingSecurity>
<underlyingSecurityTitle>
<value>common</value>
</underlyingSecurityTitle>
<underlyingSecurityShares>
<value>4000</value>
</underlyingSecurityShares>
</underlyingSecurity>
<ownershipNature>
<directOrIndirectOwnership>
<value>D</value>
</directOrIndirectOwnership>
<natureOfOwnership>
<value></value>
</natureOfOwnership>
</ownershipNature>
</derivativeHolding>
</derivativeTable>
<remarks></remarks>
<ownerSignature>
<signatureName>Steve Hoofring</signatureName>
<signatureDate>2003-10-15</signatureDate>
</ownerSignature>
</ownershipDocument>

