BTZ BlackRock Credit Allocation Income Trust

000 B000000 10/31/2009
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000 I000000 6.1
000 J000000 A
001 A000000 BLK CREDIT ALLOCATION INCOME TRUST IV
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002 A000000 100 BELLEVUE PARKWAY
002 B000000 WILMINGTON
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008 B000001 A
008 C000001 801-47710
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008 A000002 BLACKROCK FINANCIAL MANAGEMENT, INC.
008 B000002 S
008 C000002 801-48433
008 D010002 NEW YORK
008 D020002 NY
008 D030002 10022
012 A000001 COMPUTERSHARE TRUST COMPANY, N.A. (COMMON)
012 B000001 85-11340
012 C010001 CANTON
012 C020001 MA
012 C030001 02021
012 A000002 BNY MELLON SHAREOWNER SERVICES (PREFERRED)
012 B000002 85-05006

012 C010002 JERSEY CITY
012 C020002 NJ
012 C030002 07310
013 A000001 DELOITTE & TOUCHE LLP
013 B010001 PRINCETON
013 B020001 NJ
013 B030001 08540
014 A000001 BB & T AM DISTRIBUTORS, INC.
014 B000001 8-52396
014 A000002 BLACKROCK CAPITAL MARKETS, LLC
014 B000002 8-67827
014 A000003 BLACKROCK DISTRIBUTORS, INC.
014 B000003 8-048775
014 A000004 BLACKROCK INVESTMENTS, LLC
014 B000004 8-048436
014 A000005 HARRIS WILLIAMS LLC
014 B000005 8-53380
014 A000006 MGI FUNDS DISTRIBUTOR, INC.
014 B000006 8-046960
014 A000007 NATCITY INVESTMENTS, INC.
014 B000007 8-35288
014 A000008 NORTHERN FUNDS DISTRIBUTORS, LLC
014 B000008 8-051242
014 A000009 PNC CAPITAL MARKETS, INC.
014 B000009 8-32493
014 A000010 PNC INVESTMENTS LLC
014 B000010 8-066195
014 A000011 PFPC DISTRIBUTORS, INC.
014 B000011 8-045467
014 A000012 RED CAPITAL MARKETS, INC.
014 B000012 8-31175
014 A000013 BLACKROCK EXECUTION SERVICES
014 B000013 8-00000
014 A000014 BLACKROCK FUND DISTRIBUTION COMPANY
014 B000014 8-00000
015 A000001 STATE STREET BANK & TRUST COMPANY
015 B000001 C
015 C010001 BOSTON
015 C020001 MA
015 C030001 02101
015 E010001 X
015 A000002 THE BANK OF NEW YORK MELLON
015 B000002 S
015 C010002 NEW YORK
015 C020002 NY
015 C030002 10286
015 E010002 X
015 A000003 J.P. MORGAN CHASE BANK
015 B000003 S
015 C010003 NEW YORK
015 C020003 NY

015 C030003 10017
015 E010003 X
018 000000 Y
019 A000000 Y
019 B000000 294
019 C000000 BLKRKADVSR
020 A000001 DEUTSCHE BANK SECURITIES INC.
020 B000001 13-2730828
020 C000001 54
020 A000002 CITIGROUP GLOBAL MARKETS, INC.
020 B000002 11-2418191
020 C000002 35
020 A000003 WEEDEN & CO.
020 C000003 31
020 A000004 UBS SECURITIES LLC
020 B000004 13-3873456
020 C000004 21
020 A000005 MERRILL LYNCH, PIERCE, FENNER & SMITH INC.
020 B000005 13-5674085
020 C000005 18
020 A000006 JONESTRADING INSTITUTIONAL SERVICES LLC
020 B000006 51-0484896
020 C000006 16
020 A000007 CREDIT SUISSE SECURITIES (USA) L.L.C.
020 B000007 13-5659485
020 C000007 12
020 A000008 BARCLAYS CAPITAL INC.
020 C000008 9
020 A000009 LIQUIDNET, INC.
020 B000009 13-4095933
020 C000009 8
020 A000010 KNIGHT CAPITAL MARKETS LLC
020 B000010 52-2105134
020 C000010 7
021 000000 234
022 A000001 BLACKROCK LIQUIDITY FUNDS, TEMPFUND
022 B000001 52-0983343
022 C000001 737059
022 D000001 675596
022 A000002 BARCLAYS CAPITAL INC.
022 C000002 718587
022 D000002 625827
022 A000003 STATE STREET GLOBAL MARKETS, LLC
022 C000003 227650
022 D000003 224250
022 A000004 J.P. MORGAN SECURITIES INC.
022 B000004 13-3299429
022 C000004 9377
022 D000004 53028
022 A000005 DEUTSCHE BANK SECURITIES INC.
022 B000005 13-2730828

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022 D000006 20930
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022 B000007 13-5659485
022 C000007 502
022 D000007 19391
022 A000008 CITIGROUP GLOBAL MARKETS, INC.
022 B000008 11-2418191
022 C000008 13125
022 D000008 5726
022 A000009 GOLDMAN, SACHS & CO.
022 B000009 13-5108880
022 C000009 7962
022 D000009 8932
022 A000010 SANDLER O'NEILL & PARTNERS, L.P.
022 C000010 0
022 D000010 15283
023 C000000 1715769
023 D000000 1738493
024 000000 Y
025 A000001 JPMORGAN CHASE CAPITAL XXIII
025 C000001 D
025 D000001 14576
025 A000002 BARCLAYS BANK PLC
025 C000002 D
025 D000002 12435
025 A000003 JPMORGAN CHASE CAPITAL XXI SERIES U
025 C000003 D
025 D000003 8787
025 A000004 CREDIT SUISSE GUERNSEY LTD.
025 C000004 D
025 D000004 1111
025 A000005 JPMORGAN CHASE & CO.
025 C000005 E
025 D000005 881
025 A000006 THE GOLDMAN SACHS GROUP, INC.
025 C000006 E
025 D000006 231
025 D000007 0
025 D000008 0
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080 A000000 VIGILANT INSURANCE COMPANY
080 B000000 NATIONAL UNION FIRE INSURANCE COMPANY
080 C000000 85000
081 A000000 Y
081 B000000 108
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087 A020000 092508100
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SIGNATURE NEAL J. ANDREWS
TITLE CFO