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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 IRmLF9Euj8dRYXkEqu+xMEWnuRO2Raybg6TNtaKPpbOL5bWsR+xQ9kD+hjtOMawm
 sV7vHoPjNAr8sfMu2AGu+w==

<SEC-DOCUMENT>0001209191-10-003612.txt : 20100119
<SEC-HEADER>0001209191-10-003612.hdr.sgml : 20100118
<ACCEPTANCE-DATETIME>20100119190940
ACCESSION NUMBER:		0001209191-10-003612
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100115
FILED AS OF DATE:		20100119
DATE AS OF CHANGE:		20100119

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BLACKROCK CREDIT ALLOCATION INCOME TRUST IV
		CENTRAL INDEX KEY:			0001379384
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1031

	BUSINESS ADDRESS:	
		STREET 1:		100 BELLEVUE PARKWAY
		STREET 2:		MUTUAL FUND DEPARTMENT
		CITY:			WILMINGTON
		STATE:			DE
		ZIP:			19809
		BUSINESS PHONE:		888-825-2257

	MAIL ADDRESS:	
		STREET 1:		100 BELLEVUE PARKWAY
		STREET 2:		MUTUAL FUND DEPARTMENT
		CITY:			WILMINGTON
		STATE:			DE
		ZIP:			19809

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	BLACKROCK PREFERRED & EQUITY ADVANTAGE TRUST
		DATE OF NAME CHANGE:	20070629

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	BlackRock Preferred & Equity Advantage Trust
		DATE OF NAME CHANGE:	20061115

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	BlackRock Preferred & Equity Trust
		DATE OF NAME CHANGE:	20061027

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			GABBAY HENRY
		CENTRAL INDEX KEY:			0001059243

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	811-21972
		FILM NUMBER:		10534413

	MAIL ADDRESS:	
		STREET 1:		100 BELLEVUE PARKWAY
		CITY:			WILMINGTON
		STATE:			DE
		ZIP:			19809
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-01-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001379384</issuerCik>
        <issuerName>BLACKROCK CREDIT ALLOCATION INCOME TRUST IV</issuerName>
        <issuerTradingSymbol>BTZ</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001059243</rptOwnerCik>
            <rptOwnerName>GABBAY HENRY</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>40 EAST 52ND STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-01-15</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>11.6575</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes></footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Aaron Wasserman as Attorney-in-Fact</signatureName>
        <signatureDate>2010-01-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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