| Cloudgi | |
| CloudGuard AI | |
| Cloudhouse Technologies | |
| Cloudina Ltd | |
| Cloudit | |
| Cloudlearn Technologies Ltd | |
| CloudM | |
| CloudMailin | |
| CloudMargin Ltd | |
| CloudNC | |
| CloudNine Consultants Ltd | Somerset |
| Cloudoko Ltd | |
| Cloudologix | |
| CloudOrigin Ltd | |
| Cloudpay | |
| CloudPlease Ltd | |
| Cloudreach | |
| CloudScape Connect Ltd | Leicestershire |
| CloudSense Ltd | |
| Cloudserve | Dorset |
| Cloudsmith | Belfast |
| Cloudsoft Corporation Ltd | |
| Cloudsteps Ltd | |
| CloudTech24 | Surrey |
| Cloudtopia | |
| CloudXperte | |
| CloudyIT | Buckinghamshire |
| Cloudzant | |
| Clove Technology | Dorset |
| Club Studio Ltd | |
| Clubhouse Studio | |
| Clubnet Digital Ltd | Devon |
| Clue Computing Co. Ltd | Bristol |
| Clues & Co | Essex |
| Clurgo Ltd | |
| Clustermarket | |
| CLX | West Sussex |
| Clyde Biosciences | |
| Clydesoft Ltd | South Ayrshire |
| CM System Designs Ltd | |
| CM2 Web Solutions | |
| CMA Spreadsheet Solutions | Hertfordshire |
| CMC Technology Group | |
| CME Digital | Buckinghamshire |
| Cmed Research | |
| CML Microcircuits | Essex |
| CML Microsystems plc | Essex |
| CMR Surgical Ltd | |
| CMS Software Ltd | Greater London |
| CMS SupaTrak Ltd | Wiltshire |