12 Coast Regiment RA was formed in Hong Kong, in December 1940 by re-designation of 12 Heavy Regiment. The Regiment was captured at Hong Kong in December 1941 and placed in suspended animation.
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.
| Dec 40 | Re-designation of 12 Heavy Regiment | ||
| Dec 40 |  |
Hong Kong Defences | Hong Kong |
| 25 Dec 41 | Captured at Hong Kong |
Batteries
| Dec 40 | 20, 24, 35 |
| Feb 41 | 35 Battery becomes 965 Defence Battery |
| Dec 41 | 20 Coast Battery converted to Hong Kong Singapore RA due to lack of British coast artillery personnel. Re-designated 26 battery Hong Kong Singapore RA |
| Dec 41 | 24 RA, 26 HKS RA, 965 RA (attached) |
Western Fire Command
24 Battery
| Mount Davis | 3 x 9.2 inch Guns |
26 Battery
| Stonecutters | 3 x 6 inch Guns & 2 x 60 pounder Guns |
| Jubilee | 3 x 6 inch Guns |
965 Battery
| Belcher’s Upper | 1 x 6 inch Gun |
| Belcher’s Lower | 2 x 4.7 inch Guns |
| Repulse Bay | 2 x 18 pounder Guns |
| Tytam Bay | 2 x 18 pounder Guns |
| Stanley Bay | 2 x 18 pounder Guns |
| Promontory Bay | 1 x 2 pounder Gun |
| Island Bay | 1 x 2 pounder Gun |
| Deepwater Bay | 1 x 2 pounder Gun |
| Tai Ho Wan | 1 x 2 pounder Gun |