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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-08-07</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0001117042</issuerCik>
        <issuerName>MPOWER HOLDING CORP</issuerName>
        <issuerTradingSymbol>MPE</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001127939</rptOwnerCik>
            <rptOwnerName>ASPEN ADVISORS LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>152 WEST 57TH STREET</rptOwnerStreet1>
            <rptOwnerStreet2>39TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001237622</rptOwnerCik>
            <rptOwnerName>ASPEN PARTNERS SERIES A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ASPEN ADVISORS LLC</rptOwnerStreet1>
            <rptOwnerStreet2>152 WEST 57TH STREET</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Affiliate of 10% Owner</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001237613</rptOwnerCik>
            <rptOwnerName>ASPEN CAPITAL LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ASPEN ADVISORS LLC</rptOwnerStreet1>
            <rptOwnerStreet2>152 WEST 57TH STREET</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Affiliate of 10% Owner</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001237606</rptOwnerCik>
            <rptOwnerName>HECHT NIKOS</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ASPEN ADVISORS LLC</rptOwnerStreet1>
            <rptOwnerStreet2>152 WEST 57TH STREET, 39TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</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 $.001 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2006-08-07</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>10290000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.92</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnotes</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Warrants to purchase Common Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1.62</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2006-08-07</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>200000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F4"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2008-09-25</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>200000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnotes</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The shares of Common Stock reported herein were beneficially owned by Aspen Partners Series A, a series of Aspen Capital Partners L.P., a Delaware limited partnership (the &quot;Partnership&quot;).  The general partner of the Partnership is Aspen Capital, LLC, a Delaware limited liability company (the &quot;General Partner&quot;).  The managing member of the General Partner is Nikos Hecht.  The investment manager of the Partnership is Aspen Advisors LLC (the &quot;Advisor&quot;).  The managing member of the Advisor is Nikos Hecht.  As a result thereof, each of the General Partner, the Advisor and Nikos Hecht may be deemed to have beneficially owned the shares held by the Partnership.</footnote>
        <footnote id="F2">The shares of Common Stock reported herein were beneficially owned by private institutional accounts managed by the Advisor.  The managing member of the Advisor is Nikos Hecht.  As a result thereof, each of the Advisor and Nikos Hecht may be deemed to have beneficially owned the shares held by such private institutional accounts.</footnote>
        <footnote id="F3">Immediately exercisable.</footnote>
        <footnote id="F4">Warrants were cancelled in the merger with U.S. TelePacific Holdings Corp. in exchange for a cash payment equal to the number of warrants multiplied by the difference between $1.92 per share and the warrant exercise price.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Nikos Hecht, Managing Member</signatureName>
        <signatureDate>2006-08-09</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Aspen Partners, Series A, a series of Aspen Capital Partners, LP, by Aspen Capital LLC, General Partner, by Nikos Hecht, Managing Member</signatureName>
        <signatureDate>2006-08-09</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Aspen Capital LLC, by Nikos Hecht, Managing Member</signatureName>
        <signatureDate>2006-08-09</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Nikos Hecht</signatureName>
        <signatureDate>2006-08-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
