<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>3/A</documentType><periodOfReport>2002-10-29</periodOfReport><dateOfOriginalSubmission>2002-11-01</dateOfOriginalSubmission>
    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001041954</issuerCik>
        <issuerName>ITC DELTACOM INC</issuerName>
        <issuerTradingSymbol>ITCD</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001212989</rptOwnerCik>
            <rptOwnerName>MCINERNEY THOMAS E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O WELSH, CARSON, ANDERSON AND STOWE</rptOwnerStreet1>
            <rptOwnerStreet2>320 PARK AVENUE, SUITE 2500</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector><isOfficer>0</isOfficer><isTenPercentOwner>1</isTenPercentOwner><isOther>0</isOther></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeHolding><securityTitle><value>Common Stock</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>197483</value><footnoteId id="F1"/></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeHolding></nonDerivativeTable><footnotes><footnote id="F1">The number of shares of Common Stock reported as directly held by the Reporting Person was incorrect on the Reporting Person's original Form 3, and was also incorrect on a Form 4 filed by the Reporting Person on October 8, 2003.</footnote></footnotes><remarks/><ownerSignature><signatureName>Jonathan M. Rather, Attorney-in-Fact</signatureName><signatureDate>2003-10-27</signatureDate></ownerSignature></ownershipDocument>

