| Targeting Innovation Ltd | |
| Targetjobs | Oxfordshire |
| TargetR Ltd | |
| Tarragon Solutions Ltd | Hertfordshire |
| TAS Solutions Ltd | |
| TASC Software Solutions Ltd | |
| Tascom International Ltd | Berkshire |
| Tascomp Ltd | North Yorkshire |
| TaskRunner Services Ltd | |
| Taskscape Ltd | |
| Tasrie IT Services | |
| Tate Circuit Industries Ltd | Staffordshire |
| Tate Computer Technology Ltd | |
| Tatem Group | Derbyshire |
| TatvaSoft Software Development Company | |
| TauC3 Biologics Ltd | |
| Taurus Clearer Communication Ltd | Devon |
| Taurus Graphics | Oxfordshire |
| Taurus Research | |
| TauRx Therapeutics Management Ltd | |
| Tax Automation | Berkshire |
| TaxCalc | Berkshire |
| Taxi Dispatch Software | |
| Taxi Studio | |
| Tay Commercial Services | Greater Manchester |
| Tay Therapeutics Ltd | |
| Taylor Made Computer Solutions | Hampshire |
| Taylormade Digital Consultancy Ltd | |
| TBI Communications Ltd | Oxfordshire |
| TBS Mobility | Derbyshire |
| TC BioPharm | |
| TC Marketing | |
| TCG Computer Services Ltd | Hampshire |
| TCL Tech Ltd | Berkshire |
| TCR (Nottingham) Ltd | |
| TCR-Solutions | |
| TCRM | |
| TCS Biosciences Ltd | |
| TCW Communications Ltd | Surrey |
| TCW Solutions | |
| TDL Web Developments | Merseyside |
| TDMC | |
| TDSi | Dorset |
| TDW Digital Solutions | |
| Tea and Toast | |
| Tea Powered Projects | |
| TeachMatic | |
| TEAM (Energy Auditing Agency Ltd) | Buckinghamshire |
| Team Consulting | |
| Team Discovery | Surrey |