Thomas enlisted into the Northamptonshire Regiment on 3rd January 1900. He was 19 years and 3 months old, and was a Labourer by trade. On 13th October, the same year, he deserted but rejoined on the 27th. On 15th March 1901 he served in India, returning to the UK on 6th February 1908. He was transferred to Army Reserve on 19th April 1909 but re-engaged into the Colours on 6th December 1911 for 4 years service with the R..A.M.C. He entered the war in France on 18th August 1914, and remained there until 20th December 1915, when he returned to the UK. He continued in service after his service time expired under the Military Service Act of 1916. He was transferred to Class "Z", Army Reserve on demobilization on 20th February 1919.