| Caerfyrddin | Wales | W07000087 |
| Caerphilly | Wales | W07000088 |
| Caithness, Sutherland and Easter Ross | Scotland | S14000069 |
| Calder Valley | England | E14001147 |
| Camborne and Redruth | England | E14001148 |
| Cambridge | England | E14001149 |
| Cannock Chase | England | E14001150 |
| Canterbury | England | E14001151 |
| Cardiff East | Wales | W07000089 |
| Cardiff North | Wales | W07000090 |
| Cardiff South and Penarth | Wales | W07000091 |
| Cardiff West | Wales | W07000092 |
| Carlisle | England | E14001152 |
| Carshalton and Wallington | England | E14001153 |
| Castle Point | England | E14001154 |
| Central Ayrshire | Scotland | S14000109 |
| Central Devon | England | E14001155 |
| Central Suffolk and North Ipswich | England | E14001156 |
| Ceredigion Preseli | Wales | W07000093 |
| Chatham and Aylesford | England | E14001157 |
| Cheadle | England | E14001158 |
| Chelmsford | England | E14001159 |
| Chelsea and Fulham | England | E14001160 |
| Cheltenham | England | E14001161 |
| Chesham and Amersham | England | E14001162 |
| Chester North and Neston | England | E14001163 |
| Chester South and Eddisbury | England | E14001164 |
| Chesterfield | England | E14001165 |
| Chichester | England | E14001166 |
| Chingford and Woodford Green | England | E14001167 |
| Chippenham | England | E14001168 |
| Chipping Barnet | England | E14001169 |
| Chorley | England | E14001170 |
| Christchurch | England | E14001171 |
| Cities of London and Westminster | England | E14001172 |
| City of Durham | England | E14001173 |
| Clacton | England | E14001174 |
| Clapham and Brixton Hill | England | E14001175 |
| Clwyd East | Wales | W07000094 |
| Clwyd North | Wales | W07000095 |
| Coatbridge and Bellshill | Scotland | S14000070 |
| Colchester | England | E14001176 |
| Colne Valley | England | E14001177 |
| Congleton | England | E14001178 |
| Corby and East Northamptonshire | England | E14001179 |
| Coventry East | England | E14001180 |
| Coventry North West | England | E14001181 |
| Coventry South | England | E14001182 |
| Cowdenbeath and Kirkcaldy | Scotland | S14000071 |
| Cramlington and Killingworth | England | E14001183 |
| Crawley | England | E14001184 |
| Crewe and Nantwich | England | E14001185 |
| Croydon East | England | E14001186 |
| Croydon South | England | E14001187 |
| Croydon West | England | E14001188 |
| Cumbernauld and Kirkintilloch | Scotland | S14000072 |