Thomas enlisted at Inverell in October 1915, probably during one of the large recruiting rallies held in the district at that time. He was a forty five year old Bushworker at the time of enlistment. His attestation papers record that he was born at Mala, County Cork, Ireland. Thomas listed his brother as next of kin. His parents are unknown.
He joined the 4th Battalion, 14th Reinforcement and left Australia for Egypt on HMAT A62 Wandilla in February 1916. Two weeks after arriving at Alexandria in March he was sent to hospital. During April he was discharged and then attached for duty to the AIF Headquarters in Cairo. Thomas became ill again and was invalided to Australia in July. He was medically discharged in October 1916.
Thomas returned to Inverell to live where he died in 1941. His name is inscribed on the Inverell Honor Roll, the Delungra Honor Roll and the new Anzac memorial gate at Delungra.