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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2015-12-14</periodOfReport>

    <dateOfOriginalSubmission>2016-12-15</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001529864</issuerCik>
        <issuerName>Enova International, Inc.</issuerName>
        <issuerTradingSymbol>ENVA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001547308</rptOwnerCik>
            <rptOwnerName>Levertov Arad</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ENOVA INTERNATIONAL, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>175 W. JACKSON BOULEVARD, SUITE 1000</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60604</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP - Operations</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock, par value $0.00001 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2015-12-14</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5390</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6.34</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>68878</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This transaction represents the withholding by Issuer of Issuer shares to satisfy tax liabilities incurred in connection with the vesting of restricted stock units (&quot;RSUs&quot;) previously granted by the Issuer.  The timing and amount of the transaction were determined by the terms of the applicable restricted stock award and were not within the control of Mr. Levertov.</footnote>
        <footnote id="F2">The prior Form 4 is being updated to reflect a recalculation of the number of shares withheld to satisfy tax liabilities.</footnote>
        <footnote id="F3">Includes grants of RSUs that vested or which shall vest in substantially equal one-fourth increments on each of the following dates as long as grantee serves as an employee of Enova International, Inc. or an affiliate thereof through the applicable vesting date (except as noted): December 13, 2015, January 1, 2016 (if the grantee serves as an employee of Issuer through December 31, 2015), December 13, 2017 and December 13, 2018.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Lisa M. Young, attorney-in-fact</signatureName>
        <signatureDate>2016-01-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
