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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-02-23</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>2017-02-23</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1478</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>14.80</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>35429</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </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 February 23, 2017.  The timing and amount of the transaction were determined by the terms of the applicable restricted stock and were not within the control of f Mr. Higginson.</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 Enova International, Inc. 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>
        <footnote id="F4">Since the date of the reporting person's last ownership report, he transferred 2,194 shares of Issuer's common stock to his ex-wife pursuant to a domestic relations order.  The reporting person no longer reports as beneficially owned any securities owned by his ex-wife.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Lisa M. Young, Attorney-in-Fact</signatureName>
        <signatureDate>2017-02-27</signatureDate>
    </ownerSignature>
</ownershipDocument>
