| Cyber Exchange | Greater London |
| Cyber Forensics Ltd | Tyne and Wear |
| Cyber Owl | |
| Cyber Security Challenge UK | |
| Cyber Security EXPO | |
| Cyber Security Intelligence Ltd | Surrey |
| Cyber Series | |
| Cyber Ware Ltd | Cambridgeshire |
| Cyber-Duck Ltd | Hertfordshire |
| Cyber-Net Services | |
| Cyberconsult | |
| CyberCPR | |
| Cyberdoq | |
| CyberFish | |
| Cyberfort Group Ltd | |
| Cyberfrog Design Ltd | |
| Cyberia Tech | |
| CyberID Internet Solutions | Conwy |
| Cyberlogical Ltd | Berkshire |
| Cybermill | North Yorkshire |
| Cybernautix Ltd | Staffordshire |
| CyberOne | |
| Cyberpage | |
| CyberQ Group Ltd | |
| Cyberqube Ltd | Kent |
| CyberSelect Ltd | Norfolk |
| CyberSmart | Greater London |
| Cybersoftware | East Riding of Yorkshire |
| Cyberspace IT | |
| Cybertill Ltd | Merseyside |
| Cybertronix Ltd | Berkshire |
| CyberView Ltd | Greater Manchester |
| Cybrotech Ltd | Norfolk |
| CybSafe Ltd | |
| Cycle Pharmaceuticals Ltd | |
| Cyclone Technology Ltd | Worcestershire |
| Cyclops Electronics Ltd | Glasgow |
| Cyclr Systems Ltd | |
| Cydar Medical | |
| Cyfor | Greater Manchester |
| Cygenta | Gloucestershire |
| Cygnet Digital Ltd | |
| Cygnet Solutions Ltd | South Lanarkshire |
| Cygnetise Ltd | |
| CyLon | |
| Cymar Computer Ltd | Greater London |
| Cymax Computers and Communications Ltd | Essex |
| Cymru 1 | Gwynedd |
| CynapseDx Ltd | |
| Cynapto | |