| Code | Name | Region |
|---|---|---|
| GBCOE | Clowne | DBY |
| GBTWR | Clows Top | WOR |
| GBCZV | Clunbury | SHR |
| GBCLU | Clutton | BAS |
| GBCLH | Clydach | SWA |
| GBCLY | Clydebank | WDU |
| GBCLP | Clapham | LBH |
| GBLPN | Clapton | SOM |
| GBZAO | Claughton | LAN |
| GBCL5 | Clavering | ESS |
| GBCLC | Clay Cross | DBY |
| GBCYG | Claydon | OXF |
| GBCGD | Claygate | SRY |
| GBCYE | Claythorpe | LIN |
| GBCYO | Clayton | LAN |
| GBZAP | Clayton | MAN |
| GBCL4 | Clayton | STS |
| GBCEM | Clayton-le-moors | LAN |
| GBLDN | Cleadon | STY |
| GBCLE | Cleator | CMA |
| GBXCL | Cleator Moor | CMA |
| GBCCK | Cleckheaton | KIR |
| GBCTH | Cleethorpes | NEL |
| GBCL3 | Cleghorn | SLK |
| GBCEA | Cleland | NLK |
| GBCMM | Cleobury Mortimer | SHR |
| GBCHU | Chudleigh | |
| GBCMH | Chulmleigh | DEV |
| GBCRC | Church | LAN |
| GBCUB | Church Bay, Rathlin Island | MYL |
| GBCKA | Church Crookham | HAM |
| GBCCG | Church Gresley | DBY |
| GBCFZ | Church Lawford | WAR |
| GBYUR | Church Stretton | SHR |
| GBCCW | Churchstow | DEV |
| GBXCW | Chwilog | GWN |
| GBCIN | Cinderford | GLS |
| GBCIR | Cirencester | GLS |
| GBWCI | City Of Westminster | LBH |
| GBRAS | Clachan, Raasay | HLD |
| GBCLA | Clackmannan | CLK |
| GBCLS | Clacton-on-sea | ESS |
| GBXCA | Claines | WOR |
| GBCL7 | Clanfield | HAM |
| GBOXH | Clanfield | OXF |
| GBCLJ | Claonaig | AGB |
| GBCPN | Chippenham | WIL |
| GBXPP | Chipperfield | HEF |
| GBCCN | Chipping Campden | GLS |
| GBCHP | Chipping Norton | OXF |