503 (Forth) Coast Regiment RA(TA) was formed from a part of Forth Heavy Regiment RA(TA), in July 1940, with just one battery. RHQ was placed in suspended animation and the battery moved to 3 Coast Artillery Group in March 1941. The unit was reconstituted as 413 (Fife) Coast Regiment RA(TA) in January 1947.
| Jul 40 | Formed from part of Forth Heavy Regiment | |
| Jul 40 | Home Forces | UK |
| Mar 41 | Suspended animation |
Batteries
| Jul 40 | A |
| Mar 41 | Battery joined 3 Coast Artillery Group as 244 Battery |
