Per his military service record (regimental no. 4752), William Collyer was born at Wongarbon, N.S.W. He gave his age as 19 years and 3 months, his marital status as single, and his occupation as butcher. (He was the son of Thomas William Collyer and Flora Collyer).  His description on his medical was height 5 feet 8 ½ inches tall, weight 10 stone 10 lbs., with a fair complexion, blue eyes, and fair hair. His religious denomination was Church of England. He completed his certificate of medical examination on the 17th October 1915 at Wellington (while the Coo-ees were at Wellington). However he was not attested until 24th October 1915 by Captain Nicholas at Orange. A note at the top of his Attestation Paper reads ‘Presented himself 24/10/1915 with form signed by Metcalfe [the doctor at Wellington]. Sworn in 24/10/15’.
His Application to Enlist in the Australian Imperial Force form, addressed to the Recruiting Officer at Wellington, was signed by both his father Thomas Collyer and stepmother Ellen Collyer, so perhaps he had travelled back to Wongarbon to get the consent of his parents, before he caught up with the Coo-ees at Orange. He claimed that he had no previous military service.
‘William Colyer’ [sic] was listed in The Leader as one of the men who were recruited at Orange to join the Coo-ees.
‘W. Collyer’ was listed as one of the ‘Wongarbon boys’ with the Coo-ees in The Dubbo Liberal and Macquarie Advocate.
After completing the remainder of the march he went to Liverpool Camp as reinforcement for the 13th Battalion.
The Wellington Times reported that Privates W. Collyer and H. Saunders were presented with wristlet watches by the residents of Wongarbon at a farewell social while they were home on final leave on 3rd March 1916.
On his embarkation roll his address at time of enrolment was Wongarbon, N.S.W., and his next of kin is listed as his father, T. Collyer, Wongarbon, N.S.W.
On 8th March 1916 Private Collyer, along with many of the other Coo-ees, departed Sydney on the HMAT A15 Star of England. He arrived in Egypt on 11th April 1916.
On 16th April 1916 he transferred to the 4th Division Artillery at Tel-el-Kebir, and was taken on strength of the 10th Field Artillery Brigade. He was also mustered as a Driver.
On 25th May 1916 he was transferred to the Artillery Training Depot at Tel-el-Kebir.
On 28th May 1916 Gunner Collyer left Alexandria on the HMT Corsican, bound for England. He disembarked at Plymouth on 12th June 1916, for further training.
On 30th July 1916 Gunner Collyer departed England bound for France.
On 9th August 1916 Gunner Collyer was taken on strength of the 4th Division Ammunition Column in France, while it was training in the vicinity of the village of Acquin, 9 miles from St. Omer.
On 14th October 1916 his rank was changed to Driver.
On 7th March 1917 Driver Collyer’s rank was changed back to Gunner.
On 29th November 1917 Gunner Collyer was granted leave to England.
On 13th December 1917 whilst on leave in England, he was admitted to the 1st Australian Dermatological Hospital at Bulford, England, sick. He was discharged from Hospital on 1st April 1918.
On 2nd April 1918 he marched into to No. 1 Command Depot at Sutton Veny in England.
On 24th May 1918 he marched out to the Overseas Training Brigade.
On 3rd July 1918 Gunner Collyer departed Southampton for return to Le Havre, France.
Gunner Collyer rejoined his unit on 14th July 1918, when the 4th Division Ammunition Column was at Frenchencourt, France.
On 9th March 1919 Gunner Collyer left his unit, and marched into the Base Depot at Le Harve to commence his return to Australia. He departed France on 31st March 1919.
He arrived at Weymouth, England, on 1st April 1919, where he marched into the No. 4 Command Depot.
On 12th May 1919 Gunner Collyer departed England for return to Australia aboard the HT Port Napier (along with Wongarbon Coo-ee Driver Saunders).
Gunner Collyer arrived in Sydney on 5th July 1919, and was discharged on the 19th of August 1919.
 NAA: B2455, COLLYER W
 NSW Birth Registration 35916/1896 William A Collyer.