-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 UiXnifj2CqPd4QuOhSSg+Ha7cQPsi8zySDP/3P5oY/tbe0oCGysqk6MAOaO/Cy++
 BEtuL+fT6PIN6agx8HlHQA==

<SEC-DOCUMENT>0001104659-05-031535.txt : 20050707
<SEC-HEADER>0001104659-05-031535.hdr.sgml : 20050707
<ACCEPTANCE-DATETIME>20050707163633
ACCESSION NUMBER:		0001104659-05-031535
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20050705
FILED AS OF DATE:		20050707
DATE AS OF CHANGE:		20050707

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			NEUSTAR INC
		CENTRAL INDEX KEY:			0001265888
		STANDARD INDUSTRIAL CLASSIFICATION:	COMMUNICATION SERVICES, NEC [4899]
		IRS NUMBER:				000000000

	BUSINESS ADDRESS:	
		STREET 1:		46000 CENTER OAK PLAZA
		CITY:			STERLING
		STATE:			VA
		ZIP:			20166
		BUSINESS PHONE:		571-434-5400

	MAIL ADDRESS:	
		STREET 1:		46000 CENTER OAK PLAZA
		CITY:			STERLING
		STATE:			VA
		ZIP:			20166

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			LANDY JOSEPH
		CENTRAL INDEX KEY:			0001220638

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-32548
		FILM NUMBER:		05943791

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		2128780600

	MAIL ADDRESS:	
		STREET 1:		C/O WARBURG PINCUS LLC
		STREET 2:		466 LEXINGTON AVE
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10017
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>a4.xml
<DESCRIPTION>4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-07-05</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001265888</issuerCik>
        <issuerName>NEUSTAR INC</issuerName>
        <issuerTradingSymbol>NSR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001220638</rptOwnerCik>
            <rptOwnerName>LANDY JOSEPH</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O WARBURG PINCUS LLC</rptOwnerStreet1>
            <rptOwnerStreet2>466 LEXINGTON AVE</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10017</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2005-07-05</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>24112172</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>22.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>11174865</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By NeuStar, Inc. Voting Trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5654080</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The stockholders are Warburg, Pincus Equity Partners, L.P., a Delaware limited partnership, including two affiliated partnerships (&quot;WPEP&quot;).  Warburg Pincus Partners LLC, a New York limited liability company (&quot;WP Partners&quot;), which is a subsidiary of Warburg Pincus &amp; Co., a New York general partnership (&quot;WP&quot;) is the sole general partner of WPEP. Warburg Pincus LLC, a New York limited liability company, (&quot;WP LLC,&quot; and together with WPEP, WP Partners and WP, the &quot;Warburg Entities&quot;) manages WPEP. The address of each Warburg Entity is 466 Lexington Avenue, New York, NY 10017.</footnote>
        <footnote id="F2">Joseph Landy is a director of NeuStar, Inc., and a Managing Member and Co-President of WP LLC. Mr. Landy's business address is c/o Warburg Pincus, 466 Lexington Avenue, New York, NY 10017. By reason of the provisions of Rule 16a-1 of the Securities Exchange Act of 1934, as amended, Joseph Landy may be deemed to be the beneficial owner of the shares of Class A Common Stock owned by WPEP. Joseph Landy disclaims beneficial ownership of any of the Shares owned of record by any of the Warburg Entities, except to the extent of any indirect pecuniary interest therein.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Joseph P. Landy</signatureName>
        <signatureDate>2005-07-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----