123 Heavy Anti-Aircraft Regiment RA (TA) was formed at Kings Park in February 1941. The Regiment served in Anti-Aircraft Command until moving to East Africa. 123 Heavy Anti-Aircraft Regiment RA (TA) was re-designated as 16 (East Africa) Heavy Anti-Aircraft Regiment East African Artillery in June 1943. RHQ was disbanded in September 1944.
Illustrations of the formation badges under which a unit served or supported are given. This is no guarantee that the unit used this formations badge.
| Feb 41 | Formed | Kings Park, Glasgow, UK | |
| Feb 41 |  |
12 Anti-Aircraft Division, 42 Anti-Aircraft Brigade | Glasgow, UK |
| May 42 |  |
7 Anti-Aircraft Division, 43 Anti-Aircraft Brigade | Teesside, UK |
| Nov 42 |  |
East Africa Command | East Africa |
| Jun 43 | Became 16 (East Africa) Heavy Anti-Aircraft Regiment East African Artillery |
Batteries
| Feb 41 | 402, 403, 404, 417 |
| Nov 42 | 402, 404, 417 |