Coad returned to the United Kingdom in 1934 and was appointed adjutant of the 2nd Battalion, Wiltshires. He served with the battalion in Palestine during the Arab revolt. On 22 January 1937 he was seconded to the 4th Battalion, a Territorial Army (TA) unit, to serve as its adjutant, at the same time he was granted temporary rank as a captain in the TA. He was promoted to substantive captain on 18 March 1938.