| Regimental number | 521 |
| Date of birth | |
| Place of birth | Finchley, Middlesex, England |
| School | Stroud Green School, Hornsey, England |
| Age on arrival in Australia | 26 |
| Religion | Church of England |
| Occupation | Clerk |
| Marital status | Single |
| Age at embarkation | 30 |
| Next of kin | Father, W Vc Tatnall, 72 Ridge Road, Strong Green, London, England |
| Previous military service | Nil |
| Enlistment date | |
| Rank on enlistment | Private |
| Unit name | 24th Battalion, B Company |
| AWM Embarkation Roll number | 23/41/1 |
| Embarkation details | Unit embarked from Melbourne, Victoria, on board HMAT A14 Euripides on |
| Regimental number from Nominal Roll | Commissioned |
| Rank from Nominal Roll | Captain |
| Unit from Nominal Roll | 24th Battalion |
| Promotions |
2nd Lieutenant Unit: INF24 Promotion date: Lieutenant Unit: INF24 Promotion date: |
| Other details from Roll of Honour Circular | Secretary of the Warrnambool Golf Club, which presented him with a gold watch on his joining the AIF. See the Warrnambool Standard, 8 September 1916, for an obituary. |
| Fate | Killed in Action |
| Miscellaneous details (Nominal Roll) | *Noted TATNALL William Henry NR |
| Place of death or wounding | Pozieres, Somme Sector, France |
| Age at death | 31 |
| Age at death from cemetery records | 31 |
| Place of burial | Becourt Military Cemetery (Plot I, Row V, Grave No. I), Becordel-Becourt, France |
| Panel number, Roll of Honour, Australian War Memorial | 103 |
| Miscellaneous information from cemetery records | Parents: William Champion and Emily Jane TATNALL, 12 Edgar Road, Clive Vale, Hastings, England. Native of Finchely, London, England |