125 Field Regiment RA (TA) was formed in May 1939 at Sunderland with two batteries as a duplicate of 74 Field Regiment. In July 1940 it was converted to 125 Anti-Tank Regiment RA (TA).
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.
| May 39 | 23 Infantry Division | Sunderland, County Durham, UK | |
| Aug 39 | 23 Infantry Division | Whitby, Yorkshire, UK | |
| Sep 39 | 23 Infantry Division | Sunderland, County Durham, UK | |
| Jun 40 |  |
18 Infantry Division | Norfolk, UK |
| Jun 40 | Became 125 Anti-Tank Regiment |
Batteries
| May 39 | 294 (2nd Durham), 295 (3rd Durham) |