| Code | Name | Region |
|---|---|---|
| GBCBE | Camber | ESX |
| GBCAY | Camberley | SRY |
| GBCBW | Camberwell | MRT |
| GBCBS | Cambois | NBL |
| GBCMB | Camborne | CON |
| GBCMG | Cambridge | CAM |
| GBMBS | Cambs | |
| GBCAM | Cambus | CLK |
| GBCBU | Cambuslang | SLK |
| GBCMF | Camelford | CON |
| GBCGE | Cameron Bridge | FIF |
| GBCG3 | Camlough | ARM |
| GBCBT | Campbeltown | AGB |
| GBCAU | Camusnagaul | HLD |
| GBCNA | Canna, Inner Hebrides | HLD |
| GBCNI | Cannich | HLD |
| GBCAE | Caerphilly | CAY |
| GBAWS | Caersws | POW |
| GBCRW | Caerwent | MON |
| GBCYS | Caerwys | FLN |
| GBCBL | Cairnbulg | ABD |
| GBCID | Cairndow | AGB |
| GBCYN | Cairnryan | DGY |
| GBCSC | Caister On Sea | |
| GBCAI | Caistor | LIN |
| GBCCT | Calcot | WBK |
| GBCAA | Caldecote | CAM |
| GBCDC | Caldecott | NTH |
| GBCDT | Caldicot | MON |
| GBXCY | Caldy | WRL |
| GBCCA | Caledon | |
| GBCAL | Callander | STG |
| GBCLX | Callanish | SCB |
| GBCNN | Callington | CON |
| GBCNE | Calne | WIL |
| GBAHW | Calthwaite | CMA |
| GBBXR | Burwell | CAM |
| GBBWC | Burwick | ORK |
| GBBU2 | Bury | BUR |
| GBBUY | Bury | WSX |
| GBBSE | Bury Saint Edmunds | SFK |
| GBBYQ | Bushey | HRT |
| GBBYE | Bushey Heath | HRT |
| GBBMS | Bushmills | MYL |
| GBUTT | Butterleigh | DEV |
| GBBTZ | Butterwick | LIN |
| GBBUX | Buxton | DBY |
| GBBXA | Buxton | NFK |
| GBBYF | Byfleet | SRY |
| GBYEY | Byley | CHW |