| TAS Solutions Ltd | |
| TASC Software Solutions Ltd | |
| Tascom International Ltd | Berkshire |
| Tascomp Ltd | North Yorkshire |
| 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 Pharmaceuticals Ltd | |
| Tax Automation | Berkshire |
| TaxCalc | Berkshire |
| 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 | |
| TCRM | |
| TCW Communications Ltd | Surrey |
| TCW Solutions | |
| TDL Web Developments | Merseyside |
| TDSi | Dorset |
| Tea and Toast | |
| TeachMatic | |
| TEAM (Energy Auditing Agency Ltd) | Buckinghamshire |
| Team Discovery | Surrey |
| Team In India | West Sussex |
| Team K Services | Devon |
| Team Marvel Ltd | |
| Team Netsol Ltd | |
| Team Technologies Development Center, LLP | Greater London |
| Team Valley Web Design | |
| Team.energy | |
| Teamdash | |
| Teamed Ltd | |
| Teceze Ltd | Greater London |
| Tech Alchemy | |
| Tech For UK | |
| Tech Funding News | |
| Tech Guard | Hertfordshire |