<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2013-03-11</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0000888953</issuerCik>
        <issuerName>ONLINE RESOURCES CORP</issuerName>
        <issuerTradingSymbol>ORCC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001169553</rptOwnerCik>
            <rptOwnerName>TENNENBAUM CAPITAL PARTNERS LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2951 28TH STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 1000</rptOwnerStreet2>
            <rptOwnerCity>SANTA MONICA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90405</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2013-03-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>8432970</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.85</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These securities represent Common Stock and Series A-1 Redeemable Convertible Preferred Stock which were disposed of in the acquisition of the Issuer by ACI Worldwide, Inc. on March 11, 2013 and the transactions related thereto.</footnote>
        <footnote id="F2">Tennenbaum Capital Partners, LLC serves as investment advisor to, inter alia, Tennenbaum Opportunities Partners V, LP, a Delaware limited partnership, Special Value Opportunities Fund, LLC, a Delaware limited liability company, and Special Value Expansion Fund, LLC, a Delaware limited liability company, which were, prior to March 11, 2013, the registered holders of shares of Common Stock and/or Series A-1 Redeemable Convertible Preferred Stock of the Issuer beneficially owned by Tennenbaum Capital Partners, LLC.  The reporting person disclaims beneficial ownership of the reported securities, except to the extent of its pecuniary interest therein.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Elizabeth Greenwood, General Consel &amp; Chief Compliance Officer</signatureName>
        <signatureDate>2013-03-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
