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

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-12-08</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0001041954</issuerCik>
        <issuerName>ITC DELTACOM INC</issuerName>
        <issuerTradingSymbol>ITCD.OB</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001169553</rptOwnerCik>
            <rptOwnerName>TENNENBAUM CAPITAL PARTNERS LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2951 28TH STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 1000</rptOwnerStreet2>
            <rptOwnerCity>SANTA MONICA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90405</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</value>
            </securityTitle>
            <transactionDate>
                <value>2010-12-08</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>12634285</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Disposed pursuant to a merger agreement, dated as of October 1, 2010, by and among EarthLink, Inc., Egypt Merger Corp. and the Issuer.</footnote>
        <footnote id="F2">Special Value Absolute Return Fund, LLC (&quot;SVAR&quot;) was the holder of 623,647 shares of Common Stock. Special Value Continuation Partners, LP (&quot;SVCP&quot;) was the holder of 10,890,069 shares of Common Stock. Tennenbaum Opportunities Partners V, LP (&quot;TOP V&quot;) was the holder of 1,120,569 shares of Common Stock. By reason of the position of Tennenbaum Capital Partners, LLC (&quot;TCP&quot;) as the investment advisor to SVAR, SVCP, and TOPV, TCP had the power of voting and disposition of the Common Stock held by SVAR, SVCP, and TOPV.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Elizabeth Greenwood, General Counsel</signatureName>
        <signatureDate>2010-12-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
