The commandos were originally raised in June 1940 with an establishment of headquarters and 10 troops. In November 1940 Special Service Battalions were formed from existing Independent Companies and Commandos. The exception to this was No 2 Commando which became 11 Special Air Service Battalion the beginning of the parachute battalions. The Special Service Battalions consisted of a headquartes and 2 companies each of headquarters and 10 platoons. Effectively each company equated to a commando. In February 1941 the Special Service Battalions were split up and commandos reformed with a headquarters and 6 troops. The Special Service Brigade however retained its name until late in the war. The final reorganization of the commandos took place in August 1943 when it became headquarters, 5 troops and a heavy weapons troop.
Three commandos were raised in the Middle East with a different establishment, by the end of 1942 they had either been disbanded or absorbed by the S.A.S.