| Regimental number | 2345 |
| Place of birth | Co Tyrone, Ireland |
| School | 5th Class, Ireland |
| Age on arrival in Australia | 23 |
| Religion | Church of England |
| Occupation | Labourer |
| Marital status | Single |
| Age at embarkation | 26 |
| Next of kin | Mother, Mrs A Allen, 3 Queen's Street, Portadown, Ireland |
| Previous military service | Served in the Royal Irish Fusiliers for 2 years. |
| Enlistment date | |
| Place of enlistment | Liverpool, New South Wales |
| Rank on enlistment | Private |
| Unit name | 2nd Battalion, 7th Reinforcement |
| AWM Embarkation Roll number | 23/19/2 |
| Embarkation details | Unit embarked from Sydney, New South Wales, on board HMAT A67 Orsova on |
| Rank from Nominal Roll | Private |
| Unit from Nominal Roll | 2nd Battalion |
| Fate | Killed in Action |
| Age at death | 28 |
| Place of burial | Belgian Battery Corner Cemetery (Plot II, Row H, Grave 5), Belgium |
| Panel number, Roll of Honour, Australian War Memorial | 31 |
| Miscellaneous information from cemetery records | Commemorated on Portadown and District War Memorial, Co Armagh, Northern Ireland. |
| Family/military connections | Cousin: 4310 Pte Herbert Fosbery ALLEN, 20th Bn, killed in action, 5 August 1916. |
| Other details |
War service: Egypt, Gallipoli, Western Front Medals: 1914-15 Star, British War Medal, Victory Medal |
| Sources | NAA: B2455, ALLEN William |