| Name |
| Cardiff City Council Insurance |
| Carrick District Council |
| Castle Point Borough Council |
| Castlemilk East Housing |
| Cds Co-Operative |
| Ceredigion County Council |
| Cernach HSG Co-Op Limited |
| Chart Management Agency |
| Charter Community Housing |
| Chelmer Housing Partnership |
| Chester-Le-Street District Council |
| Chiltern Hundreds Rent |
| City & County of Swansea |
| City Of Bradford Metropolitan District Council |
| City Of Salford |
| City South Manchester Housing Trust |
| Cleveland Housing Trust |
| Coastline Housing Asociation |
| Cobalt Housing Limited |
| Colchester Borough Council |
| Community Housing Association |
| Connswater Housing |
| Conwy County Borough Council |
| Conwy County Borough Council |
| Coop Development Services |
| Co-Op Payment |
| Cornwall Council |
| Cornwall Rural Housing Association |
| Corporation of London |
| Cosmopolitan Housing Rnt |
| Coventry Newspapers |
| Craven Housing Limited |
| Craymill Housing Co-Op |
| Crosswords Debt Recovery |
| Cymdeithat Tai Can |
| D P Domestics |
| Dacorum Borough Council |
| Darlington Borough Council |
| Dartford Borough Council |
| DCF Financial Services |
| De Cobains Rentals |
| Denbighshire County Council |
| Dental Warehouse Limited T/A Dial A TV |
| Derby Daily Telegraph Limited |
| Derwent Housing Association |
| Derwentside District Council |
| Dial A TV (York) Limited |
| Dial A TV Limited |
| Dial A TV Services |
| Doncaster Metropolitan Borough Council |