| Code | Name | Region |
|---|---|---|
| GBCEY | Cowley | OXF |
| GBCWG | Cowling | NYK |
| GBCXB | Coxbench | DBY |
| GBCDY | Cradley | DUD |
| GBCRH | Cradley Heath | |
| GBCRG | Craigavon | CGV |
| GBCGA | Craigellachie | MRY |
| GBCGJ | Craighouse, Isle Of Jura | AGB |
| GBCNU | Craignure | AGB |
| GBCRJ | Crail | FIF |
| GBCMT | Cramlington | NBL |
| GBCMD | Cramond | EDH |
| GBCBO | Cranborne | DOR |
| GBCRU | Cranbourne | BRC |
| GBCBK | Cranbrook | KEN |
| GBCRF | Cranfield | CBF |
| GBCTG | Cotgrave | NTT |
| GBOTA | Cotham | NTT |
| GBOON | Coton | CAM |
| GBKOT | Cottenham | CAM |
| GBCTT | Cotterstock | NTH |
| GBCXT | Cottingham | |
| GBCOU | Coulport | AGB |
| GBCSD | Coulsdon | CRY |
| GBOUP | Coupar Angus | PKN |
| GBCWO | Cousley Wood | ESX |
| GBCV9 | Cove | AGB |
| GBCVE | Cove | SCB |
| GBACV | Cove (aberdeen) | ABD |
| GBCVI | Cove (leith) | EDH |
| GBCGT | Covent Garden | WSM |
| GBCVT | Coventry | COV |
| GBCOV | Coverack | CON |
| GBCDG | Cowbridge | VGL |
| GBCWD | Cowden | KEN |
| GBCOH | Cowdenbeath | FIF |
| GBCPH | Copthorne | WSX |
| GBCBG | Corbridge | NBL |
| GBCBY | Corby | NTH |
| GBCFM | Corfe Mullen | DOR |
| GBCYK | Corley | |
| GBCRD | Cornhill-on-tweed | NBL |
| GBCW9 | Cornwall | DEV |
| GBCNW | Cornwell | OXF |
| GBRWO | Cornwood | DEV |
| GBCOR | Corpach | HLD |
| GBORR | Corran | AGB |
| GBCRS | Corsham | WIL |
| GBORW | Corwen | DEN |
| GBCOY | Coryton | ESS |