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. 503 (Forth) Coast Regiment RA (TA) was reconstituted as 413 (Fife) Coast Regiment RA (TA) in January 1947.
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.
| Jul 40 | Formed from part of Forth Heavy Regiment | ||
| Jul 40 |  |
Scottish Command | Dundee, UK |
| Mar 41 | Suspended animation |
Batteries
| Jul 40 | A (Castle Green) |
| Mar 41 | Battery joined 3 Coast Artillery Group as 244 Battery |