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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-03-13</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001627640</rptOwnerCik>
            <rptOwnerName>Higginson John</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ENOVA INTERNATIONAL, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>175 WEST JACKSON BLVD., 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>VP - Chief Technology Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.00001 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2017-03-13</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2122</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>13.55</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>45383</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This transaction represents the withholding by Enova International, Inc. (&quot;Issuer&quot;) of Issuer's shares to pay taxes in connection with the vesting of restricted stock on March 9, 2017. The reporting person made his election to withhold these shares on March 13, 2017. As required by the 2014 Long-Term Incentive Plan, as amended in February 2016, the number of shares withheld was determined based upon the value of the Issuer's common stock on the vesting date.</footnote>
        <footnote id="F2">Includes a grant of Restricted Stock Units (&quot;RSUs&quot;) that have vested or shall vest in substantially equal one-fourth increments on each of the following dates as long as grantee serves as an employee of Issuer  or an affiliate thereof through the applicable vesting date: March 9, 2016, March 9, 2017, March 9, 2018, and March 9, 2019.</footnote>
        <footnote id="F3">Includes a grant of RSUs that have vested or shall vest in substantially equal one-third increments on each of the following dates as long as grantee serves as an employee of Issuer or an affiliate thereof through the applicable vesting date: February 23, 2017, February 23, 2018 and February 23, 2019.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Lisa M. Young, Attorney-in-Fact</signatureName>
        <signatureDate>2017-03-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
