Private Courtney put his age as 21 years and 1 month when he enlisted at South Melbourne on 6 July 1917. He gave his next of kin as his sister, Rose Courtney, who resided at 55 Studley Road, Forest Gate, Essex; in May 1918 he changed his next of kin to name his father, of the same address. Perusal of records of the 1901 UK Census indicates that Courtney was born in 1900 to Thomas William Courtney (a brass foundry fettler) and Emma Courtney, so he appears to have wound his age forward for purposes of enlisting without requiring parental consent. He was punished for being AWOL for 3 days, until arrested, near Salisbury in April 1918; in May 1918 he received a gunshot wound to his thigh and groin. For this he was invalided out, and seems to have been given a pension for being partially permanently disabled. He arrived back in Australia in November 1918, but by early 1924 he gave notification that his new address was in Essex again.

On enlistment Courtney was 5'9", weighed 130 lb, with fair hair and complexion, and brown eyes. He gives his address as East Melbourne, but the nearest Princess St to East Melbourne is in Richmond; his occupation is described as clerk, but his profession is referred to as seaman in his repatriation papers.