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

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2016-05-04</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001142701</issuerCik>
        <issuerName>UNITED ONLINE INC</issuerName>
        <issuerTradingSymbol>UNTD</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001464790</rptOwnerCik>
            <rptOwnerName>B. Riley Financial, Inc.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>21860 BURBANK BOULEVARD, SUITE 300 SOUTH</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>WOODLAND HILLS</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>91367</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001642765</rptOwnerCik>
            <rptOwnerName>BRC Partners Opportunity Fund, LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>11100 SANTA MONICA BOULEVARD, SUITE 800</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LOS ANGELES</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001396092</rptOwnerCik>
            <rptOwnerName>World Funds Trust</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>11100 SANTA MONICA BOULEVARD, SUITE 800</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LOS ANGELES</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001658704</rptOwnerCik>
            <rptOwnerName>B. RILEY CAPITAL MANAGEMENT, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>11100 SANTA MONICA BOULEVARD, SUITE 800</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LOS ANGELES</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001337002</rptOwnerCik>
            <rptOwnerName>B. Riley &amp; Co., LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>11100 SANTA MONICA BOULEVARD, SUITE 800</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LOS ANGELES</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001207269</rptOwnerCik>
            <rptOwnerName>RILEY BRYANT R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>11100 SANTA MONICA BOULEVARD, SUITE 800</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LOS ANGELES</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.0001 per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1427228</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See notes</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.0001 per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>659283</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F5"/>
                    <footnoteId id="F6"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See notes</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.0001 per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>21203</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F6"/>
                    <footnoteId id="F7"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See notes</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.0001 per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>692794</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F6"/>
                    <footnoteId id="F8"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See notes</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.0001 per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>734434</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F6"/>
                    <footnoteId id="F9"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See notes</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.0001 per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2750</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F10"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This Form 3 is filed jointly by BRC Partners Opportunity Fund, LP (&quot;BPOF&quot;), B. Riley Diversified Equity Fund (the &quot;Mutual Fund&quot;), B. Riley Capital Management, LLC (&quot;BRCM&quot;), B. Riley &amp; Co., LLC (&quot;BRC&quot;), Bryant R. Riley and B. Riley Financial, Inc. (&quot;BRF&quot;) (collectively, the &quot;Filing Persons&quot;). Each of the Filing Persons disclaims beneficial ownership of the outstanding shares of Common Stock, par value $0.0001 per share (&quot;United Common Stock&quot;), of United Online, Inc., a Delaware corporation (&quot;United&quot; or the &quot;Issuer&quot;), reported herein except to the extent of his or its pecuniary interest therein.</footnote>
        <footnote id="F2">The Filing Persons are filing this Form 3 solely because, as a result of the Voting Agreement, dated as of May 4, 2016 (the &quot;Voting Agreement&quot;), among BRF and the directors of the Issuer who own shares of United Common Stock (collectively, the &quot;United Stockholders&quot;), BRF may be deemed to have beneficial ownership of such shares of United Common Stock beneficially owned by the United Stockholders. The Voting Agreement was entered into in connection with the Agreement and Plan of Merger, dated as of May 4, 2016, by and among BRF, Unify Merger Sub, Inc., a wholly-owned subsidiary of BRF, and the Issuer, pursuant to which Unify Merger Sub, Inc. will merge with and into the Issuer.</footnote>
        <footnote id="F3">(Continued from footnote 3) Neither the filing of this statement nor any of its contents shall be deemed to constitute an admission by any Filing Person that it is the beneficial owner of any United Common Stock owned by the United Stockholders referred to herein for purposes of Section 16 of the Securities and Exchange Act of 1934, as amended (the &quot;Act&quot;). The Filing Persons have no pecuniary interest in such United Common Stock owned by the United Stockholders. Each Filing Person, pursuant to Rule 16a-1(a)(4) promulgated under the Act, hereby expressly disclaims that it is the beneficial owner of such United Common Stock owned by the United Stockholders.</footnote>
        <footnote id="F4">Includes 1,427,228 shares held directly by BPOF, the Mutual Fund, BRCM and BRC.</footnote>
        <footnote id="F5">Represents 659,283 shares of United Common Stock owned directly by BPOF.</footnote>
        <footnote id="F6">BRCM serves as the investment manager and general partner of BPOF, and as the investment advisor to the Mutual Fund and of certain separately managed accounts (the &quot;Separately Managed Accounts&quot;). BRF is the parent company of BRCM and BRC. By virtue of these relationships, each of BRCM and BRF may be deemed to beneficially own the shares of United Common Stock owned directly by BPOF and the Mutual Fund and held in the Separately Managed Accounts, and BRF may also be deemed to beneficially own the Shares owned directly by BRC.</footnote>
        <footnote id="F7">Represents 21,203 shares of United Common Stock owned directly by the Mutual Fund.</footnote>
        <footnote id="F8">Represents 692,794 shares of United Common Stock owned directly by BRCM.</footnote>
        <footnote id="F9">Represents 734,434 shares of United Common Stock owned directly by BRC.</footnote>
        <footnote id="F10">Represents 2,750 shares of United Common Stock owned directly by Bryant R. Riley.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Bryant R. Riley, Chief Executive Officer of B. Riley Capital Management, LLC, General Partner of BRC PARTNERS OPPORTUNITY FUND, LP</signatureName>
        <signatureDate>2016-05-16</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Bryant R. Riley, Chief Executive Officer of B. Riley Capital Management, LLC, Investment Advisor of B. RILEY DIVERSIFIED EQUITY FUND</signatureName>
        <signatureDate>2016-05-16</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Bryant R. Riley, Chief Executive Officer of B. RILEY CAPITAL MANAGEMENT, LLC</signatureName>
        <signatureDate>2016-05-16</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Bryant R. Riley, Chairman of B. RILEY &amp; CO., LLC</signatureName>
        <signatureDate>2016-05-16</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Bryant R. Riley</signatureName>
        <signatureDate>2016-05-16</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Bryant R. Riley, Chief Executive Officer of B. RILEY FINANCIAL, INC.</signatureName>
        <signatureDate>2016-05-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
