Lawrence was serving with the 141st Field Ambulance when, on 27th July 1917, he was admitted 'sick' into the hospital of the 1st Field Ambulance. On 31st July 1917 he was discharged from the hospital of the 1st Field Ambulance and rejoined his unit. On 13th July 1919 he proceeded to No 1 Concentration Camp, Cologne for dispersal and was struck off the strength of the unit.