<SUBMISSION>
<ACCESSION-NUMBER>0001181431-06-056408
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20060929
<FILING-DATE>20061003
<DATE-OF-FILING-DATE-CHANGE>20061003
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>Western Union CO
<CIK>0001365135
<ASSIGNED-SIC>7389
<IRS-NUMBER>204531180
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>100 SUMMIT AVENUE
<CITY>MONTVALE
<STATE>NJ
<ZIP>07645
<PHONE>(201) 263-5949
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>100 SUMMIT AVENUE
<CITY>MONTVALE
<STATE>NJ
<ZIP>07645
</MAIL-ADDRESS>
</ISSUER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>THOMAS WILLIAM DAVID
<CIK>0001223474
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-32903
<FILM-NUMBER>061125474
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>C/O FIRST DATA CORP
<STREET2>10825 OLD MILL ROAD M-10
<CITY>OMAHA
<STATE>NE
<ZIP>68154
<PHONE>402-951-7008
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>FIRST DATA CORPORATION
<STREET2>10825 FARNAM DR, C-12
<CITY>OMAHA
<STATE>NE
<ZIP>68154
</MAIL-ADDRESS>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>rrd132253.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-09-29</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001365135</issuerCik>
        <issuerName>Western Union CO</issuerName>
        <issuerTradingSymbol>WU</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001223474</rptOwnerCik>
            <rptOwnerName>THOMAS WILLIAM DAVID</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>12500 EAST BELFORD AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>ENGLEWOOD</rptOwnerCity>
            <rptOwnerState>CO</rptOwnerState>
            <rptOwnerZipCode>80112</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP &amp; Pres. of the Americas</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2006-09-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>33159</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>33159</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee Stock Option (Right to Buy).</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>19.13</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2006-09-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>239968</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2016-09-29</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>239968</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>239968</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee Stock Option (Right to Buy).</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>20.01</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2006-09-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>70256</value>
                    <footnoteId id="F3"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <value>2016-02-08</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>70256</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>70256</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Restricted stock award which vests in full, if the executive is still employed by the Company at the time, on the third anniversary of the date of grant.</footnote>
        <footnote id="F2">This option vests in four equal annual installments beginning on September 29, 2007.</footnote>
        <footnote id="F3">Represents option acquired by reporting person as a result of the adjustment of an option to purchase shares of First Data Corporation common stock held by the reporting person. This adjustment occurred pursuant to the terms of the Employee Matters Agreement, dated September 29, 2006, between The Western Union Company and First Data Corporation.</footnote>
        <footnote id="F4">The option vests in four equal annual installments beginning on February 8, 2007.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Sarah J. Kilgore as Attorney-in-Fact for William D. Thomas</signatureName>
        <signatureDate>2006-10-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
