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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-05-08</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001604174</issuerCik>
        <issuerName>Eagle Point Credit Co Inc.</issuerName>
        <issuerTradingSymbol>ECC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001459925</rptOwnerCik>
            <rptOwnerName>TRIDENT V, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>STONE POINT CAPITAL LLC</rptOwnerStreet1>
            <rptOwnerStreet2>20 HORSENECK LANE</rptOwnerStreet2>
            <rptOwnerCity>GREENWICH</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06830</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001621506</rptOwnerCik>
            <rptOwnerName>Trident Capital V, L.P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O STONE POINT CAPITAL LLC</rptOwnerStreet1>
            <rptOwnerStreet2>20 HORSENECK LANE</rptOwnerStreet2>
            <rptOwnerCity>GREENWICH</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06830</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, par value $0.001 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2018-05-08</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1596747</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>17.94</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3336437</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This Form 4 is being filed jointly by Trident V, L.P. (&quot;Trident V&quot;) and Trident Capital V, L.P. (&quot;Trident V GP&quot;). Trident V GP, as the general partner of Trident V, may be deemed a beneficial owner of securities held by Trident V, but disclaims such beneficial ownership except to the extent of Trident V GP's pecuniary interest therein. The reporting persons' beneficial ownership of Issuer securities disclosed herein does not include those Issuer securities held by Eagle Point Credit Management LLC (&quot;EPCM&quot;), the Issuer's investment advisor. As from May 8, 2018, each reporting person disclaims beneficial ownership of Issuer securities held by EPCM.</footnote>
        <footnote id="F2">These shares were sold in multiple transactions and the price reported is a weighted average. The sale price ranged from $17.49425 to $18.41500 per share. The reporting persons undertake to provide the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Trident V, L.P.
By: Trident Capital V, L.P., its sole general partner,
By: DW Trident V, LLC, a general partner,
By: /s/ Jacqueline Giammarco, Vice President</signatureName>
        <signatureDate>2018-05-10</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Trident Capital V, L.P., By: DW Trident V, LLC, a general partner, By: /s/ Jacqueline Giammarco, Vice President</signatureName>
        <signatureDate>2018-05-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
