| Turtl | |
| Turtle Design | Edinburgh |
| Turtlereality Web Design | Wiltshire |
| Tutorbloc | |
| TutorCruncher Ltd | |
| Tuune | Greater London |
| TV Village Ltd | Stirling |
| TVCables | Bedfordshire |
| TVM Northampton | Northamptonshire |
| TW Media | Surrey |
| TWDA | Northumberland |
| TWDG Ltd | Nottinghamshire |
| Tweave.Tech | |
| Tweed Solutions | Scottish Borders |
| TWEFDA Ltd | |
| Twenty3 | |
| TwentyCi Ltd | Buckinghamshire |
| TwentyEleven Web Design | Warwickshire |
| TwentyTech | |
| Twentytwo Digital | West Midlands |
| TWF Solutions Ltd | |
| TWI Ltd | |
| TWID Design | |
| twig | |
| Twig Education Ltd | Glasgow |
| Twilight Zone Engineering Ltd | |
| Twine | |
| Twine | Greater London |
| TwistedPair | |
| Twistgraphics Studio | Surrey |
| Two Digital Marketing Ltd | Berkshire |
| Two Heads Ltd | East Riding of Yorkshire |
| Two Plus Two Multimedia Ltd | Buckinghamshire |
| Two-Tone Designs | Essex |
| Twofold Ltd | Berkshire |
| TWR Computing | South Yorkshire |
| TX Corporation Ltd | |
| Txtlocal Ltd | Berkshire |
| Tycom Ltd | Aberdeen |
| Tyder Ltd | Mid-Ulster |
| TYG Oncology Ltd | |
| TYG Oncology Ltd | |
| Tyk Technologies | |
| Tylden Ltd | Hampshire |
| Tyler Lewis | Greater Manchester |
| Tyler Webdesign | Greater London |
| Tymit Ltd | |
| Tyne Metropolitan College | |
| Tyne Tech Repairs | |
| Tyneside Linux User Group | Tyne and Wear |