During World War I Allison worked for the War Office and the Admiralty, producing propaganda and later joined the Royal Flying Corps (later renamed the Royal Air Force). After the war Allison also moved into broadcasting, joining the BBC and becoming the first person to commentate on the radio on events such as the Derby and the Grand National (with the BBC's racing correspondent Meyrick Good), as well as the annual England "v." Scotland international, and the FA Cup Final in 1927, between Cardiff City and Arsenal. By this time, he had already formed a strong association with the latter club.