12 Medium Regiment RA was formed in January 1943 from disbanded Super Heavy Batteries and Defence Troops at Larbert, Stirling. It was organised with two batteries and served as a holding unit. In March 1946 the Regiment was disbanded at Selby, Yorkshire.
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.
| Jan 43 | Formed from RA units | Stirling, Stirlingshire, UK | |
| Jan 43 | Home Forces | UK | |
| Jul 45 |  |
48 Infantry Division | UK |
Batteries
| Jan 43 | 87, 88 |