| Code | Name | Region |
|---|---|---|
| GBCAC | Castle Cary | SOM |
| GBCAD | Castle Donington | LEC |
| GBCTD | Castle Douglas | DGY |
| GBEHE | Castle Hedingham | ESS |
| GBVCL | Castle Vale | BIR |
| GBCBA | Castlebay | ELS |
| GBCD9 | Cardonald | GLG |
| GBCAX | Carlisle | CMA |
| GBRLW | Carloway | HLD |
| GBCAO | Carlton | NYK |
| GBCRV | Carlton Colville | SFK |
| GBCOI | Carlton In Lindrick | NTT |
| GBORN | Carlton On Trent | NTT |
| GBCAK | Carluke | SLK |
| GBCMR | Carmarthen | |
| GBCNF | Carnforth | LAN |
| GBCAH | Carnlough | LRN |
| GBCRQ | Carno | POW |
| GBCNS | Carnoustie | ANS |
| GBCAZ | Carnwath | SLK |
| GBCRA | Carradale | AGB |
| GBCBD | Carrbridge | HLD |
| GBCFG | Carrickfergus | CKF |
| GBCKO | Carrickmore | OMH |
| GBCRT | Carrington | TRF |
| GBRRO | Carron | HLD |
| GBZAK | Canning Town | LND |
| GBZAL | Cannington | SOM |
| GBCNK | Cannock | STS |
| GBCBI | Canonbie | DGY |
| GBCNB | Canterbury | KEN |
| GBCNL | Cantley | DNC |
| GBCTY | Cantley | NFK |
| GBCAN | Canvey Island | ESS |
| GBCCL | Cape Cornwall | CON |
| GBCAP | Capel | SRY |
| GBPHR | Capel Hendre | CMN |
| GBCPU | Capenhurst | CHW |
| GBCPG | Cappagh | DGN |
| GBCPF | Captain Field | |
| GBCAB | Carbost | HLD |
| GBOFT | Carcroft | DNC |
| GBCDF | Cardiff | CRF |
| GBCAR | Cardigan (aberteifi) | CGN |
| GBC5T | Cardington | BDF |
| GBCIM | Cardinham | CON |
| GBCLV | Calverley | ERY |
| GBVTN | Calverton | MIK |
| GBCTX | Calverton | NTT |
| GBCAQ | Cam | GLS |