126 Heavy Anti-Aircraft Regiment RA(TA) was formed at Dowling, Dunbartonshire in July 1941. The Regiment was disbanded in December 1945 at Tendring, Clacton on Sea, Essex.
| Jul 41 | Formed | Dunbartonshire, UK |
| Jul 41 | 35 Anti-Aircraft Brigade, 5 Anti-Aircraft Division | Portsmouth, Hampshire, UK |
| Jul 42 | 42 Anti-Aircraft Brigade, 12 Anti-Aircraft Division | Firth of Clyde, Scotland |
| Sep 42 | 9 Anti-Aircraft Division | UK |
| Aug 43 | 40 Anti-Aircraft Brigade, 5 Anti-Aircraft Group | Nottinghamshire, UK |
| Jan 44 | 40 Anti-Aircraft Brigade, 2 Anti-Aircraft Group | Southern England |
| Nov 44 | 40 Anti-Aircraft Brigade, 9 Anti-Aircraft Group | East Anglia, UK |
Batteries
| Jul 41 | 423, 425, 426 |
| Jul 42 | 423, 425, 426, 431 |
| Feb 45 | 423, 425, 426 |
