<SEC-DOCUMENT>0001645768-19-000007.txt : 20190221
<SEC-HEADER>0001645768-19-000007.hdr.sgml : 20190221
<ACCEPTANCE-DATETIME>20190221182712
ACCESSION NUMBER:		0001645768-19-000007
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20190215
FILED AS OF DATE:		20190221
DATE AS OF CHANGE:		20190221

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Danaher John T
		CENTRAL INDEX KEY:			0001645768

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37470
		FILM NUMBER:		19623366

	MAIL ADDRESS:	
		STREET 1:		C/O TRANSUNION
		STREET 2:		555 WEST ADAMS STREET
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60661

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			TransUnion
		CENTRAL INDEX KEY:			0001552033
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-CONSUMER CREDIT REPORTING, COLLECTION AGENCIES [7320]
		IRS NUMBER:				611678417
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		555 WEST ADAMS STREET
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60661
		BUSINESS PHONE:		(312) 985-2000

	MAIL ADDRESS:	
		STREET 1:		555 WEST ADAMS STREET
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60661

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	TransUnion Holding Company, Inc.
		DATE OF NAME CHANGE:	20120612
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>wf-form4a_155079161752796.xml
<DESCRIPTION>FORM 4/A
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2019-02-15</periodOfReport>

    <dateOfOriginalSubmission>2019-02-20</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001552033</issuerCik>
        <issuerName>TransUnion</issuerName>
        <issuerTradingSymbol>TRU</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001645768</rptOwnerCik>
            <rptOwnerName>Danaher John T</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O TRANSUNION</rptOwnerStreet1>
            <rptOwnerStreet2>555 WEST ADAMS STREET</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60661</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP - Consumer Interactive</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2019-02-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>46244</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>126609</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2019-02-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F3"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>28421</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>63.13</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>98188</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2019-02-20</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F4"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>7931</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>106119</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Reflects shares of Common Stock earned upon the vesting of performance share units granted on February 15, 2016.</footnote>
        <footnote id="F2">This Form 4/A amends the Form 4 filed on February 20, 2019, and corrects inadvertent administrative errors in the number of shares of Common Stock reported as beneficially owned following the reported transactions.</footnote>
        <footnote id="F3">Reflects shares of Common Stock withheld by the Company in payment of tax liability incident to the vesting of restricted stock units and performance share units granted on February 15, 2016.</footnote>
        <footnote id="F4">Represents a grant of restricted stock units that vest on the third anniversary of the date of grant.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Michael J. Forde, by power of attorney</signatureName>
        <signatureDate>2019-02-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
