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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-02-17</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>2017-02-17</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>12076</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>14.80</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>48983</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock option (right to buy) with limited SAR</value>
                <footnoteId id="F5"/>
                <footnoteId id="F6"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>14.80</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2017-02-17</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>27084</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F7"/>
            </exerciseDate>
            <expirationDate>
                <value>2024-02-17</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common stock, par value $0.00001 per share</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>27084</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>41334</value>
                    <footnoteId id="F8"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Reflects a grant of Restricted Stock Units (&quot;RSUs&quot;) that shall vest in substantially equal one-fourth increments on each of the following dats as long as grantee serves as an employee of Enova International, Inc. (&quot;Issuer&quot;) or an affiliate through the applibable vesting date: February 17, 2018, February 17, 2019, February 17, 2020, and February 17, 2021.</footnote>
        <footnote id="F2">Includes a grant of RSUs 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">On February 27, 2017, the reporting person filed a Form 4 in connection with the vesting of restricted stock on February 23, 2017.  As the current granting event reflected in this Form 4 precedes the event reflected in the Form 4 filed February 27, 2017, the total amount of shares beneficially owned by the reporting person reported on the Form 4 filed February 27, 2017 was inadvertently miscalculated.</footnote>
        <footnote id="F5">The limited stock appreciation right (&quot;SAR&quot;) and employee stock option were granted in tandem. Accordingly, the exercise of one results in the expiration of the other. The SAR may be exercised only during the period beginning on the first day following the date that a &quot;Change in Control&quot; of Issuer occurs (as defined in the related grant agreement) and ending on the thirtieth day following such date. Upon exercise, the grantee shall be able to receive an amount equal to the product computed by multiplying (i) the excess of the &quot;Offer Value Per Share&quot; over the exercise price of the underlying option by (ii) the number of shares with respect to which the SAR is being exercised; provided, that such amount shall only be payable in the event an &quot;Offer&quot; is made.</footnote>
        <footnote id="F6">The &quot;Offer Value Per Share&quot; means the average selling price of Issuer's common stock during the period of 30 days ending on the date on which the SAR is exercised. &quot;Offer&quot; means any tender offer or exchange offer for outstanding shares of Enova representing at least 30% of the total voting power of the stock of Enova, or an offer to purchase assets from Enova that have a total gross fair market value equal to or more than 40% of the total gross fair market value of all of the assets of Enova, other than an offer made by Enova.</footnote>
        <footnote id="F7">The options 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 17, 2018, February 17, 2019, and February 17, 2020.</footnote>
        <footnote id="F8">Includes a grant of options 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>2017-03-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
