In January 1939 a specification was issued for a gun to replace the 6 inch 26 cwt howitzers in use with most medium batteries. The first units were equipped in UK in the summer of 1941 and in North Africa a year later, 20 guns equipped British and Free French batteries at El Alamein. Subsequently, it also equipped Canadian, Australian, South African, Polish and Indian regiments, and after the war, it was also used by New Zealand. In the Second World War the normal organization was a regiment of 16 guns organized into two batteries. The 5.5 was retained in service after the war. It was used by the Royal Artillery on operations in Korea, South Arabia and Borneo. It was probably used by the Indian Army in wars against Pakistan, and was used by the Pakistan Army against India in the mountains of Kashmir during the Kargil War of 1999.