The RAF reserved the designation Liberator IV for the Ford-built B-24E, but there is no evidence that any of these aircraft were actually received in the United Kingdom. Instead, the few aircraft listed on RAF rolls as Liberator IVs were actually conversions of later Mk-VIs (primarily B-24H and J versions), as well as a few aircraft handed over to the RAF from USAAF stocks.
RAF serials listed as Liberator IVs were BZ970, TS519/TS539, VB852, VB904, VD249, and BZ970. BZ970 was converted into C.IV transport configuration. The TS519/539 lot were converted as follows:
TS519/520-->B.IV TS521/523-->C.IV TS524/526-->B.IV TS527--> C.IV TS528--> B.IV TS529/530-->C.IV TS531/532-->B.IV TS533/534-->C.IV TS535--> B.IV TS536--> C.IV TS537 (no record) TS538/539-->C.IV VB852 was ex-USAAF B-24J-1-FO 42-50744 handed over to the RAF. It was converted to C.IV in January of 1945. VB994 was ex-USAAF B-24H-15-FO 42-52766 handed over to the RAF. It was later converted to Mk. VI. VD249 was ex-USAAF B-24J-60-CF 44-10533 handed over to the RAF.