Thomas enlisted on 4th March 1915. He was 40 years and 40 days old, and was a Coal Miner by trade. He embarked at Southampton on 10th August 1915, then disembarking the next day at Rouen, entered the war in France on 11th August 1915. He was appointed acting Corporal on 30th May 1917, which reverted back to his permanent rank of Private on return to England for demobilization on 9th January 1919. He was transferred to Class Z Army Reserve on 9th February 1919 on demobilization.