| Chaser Technologies Ltd | Greater London |
| Chatamo | |
| ChatBotKit | |
| ChatCSV | |
| Chatloop Ltd | |
| Chatsworth Media | Derbyshire |
| Chatterbox Ltd | Surrey |
| Chattermill | |
| Chayn | |
| Cheadle DATA Recovery Ltd | Greater Manchester |
| Cheap Web Design | Surrey |
| Check It Out | |
| Checkbot | |
| Checkd Group | |
| CheckMySystems Ltd | |
| Checkout.com | Greater London |
| Checkstep | |
| Cheeky Communications Ltd | Kent |
| Cheeky Munkey IT Support | Hertfordshire |
| Cheerfy Ltd | |
| Cheil UK | |
| Chelmer Web Design | Essex |
| Chelsea Apps | |
| Chelsoft Club Membership Software | Gloucestershire |
| Cheltenham Computer Repairs | Gloucestershire |
| Cheltenham Computer Specialists | Gloucestershire |
| Chembiotech Laboratories | |
| ChemOvation Ltd | |
| ChemSoft Ltd | Cheshire |
| Cheqd | |
| Chersoft Ltd | |
| Cheshire Datasystems Ltd | Greater Manchester |
| Chess Digital Ltd | Renfrewshire |
| Chess ICT | Oxfordshire |
| Chess Logistics Technology Ltd | |
| Chester Marketing Solutions Ltd | |
| Chesterton Software Development Ltd | |
| ChestPal Pro | |
| Chestysoft | North Yorkshire |
| Cheviot Data Systems | |
| Chiaro Technology Ltd | |
| Chichester Website Design | |
| Chicsystems | Norfolk |
| Chillblast | Dorset |
| Chillfire Ltd | Surrey |
| Chilliapple Ltd | |
| Chillibyte | |
| Chiltern Telecom Ltd | |
| Chilternmac | Cornwall |
| Chilton Computing | |