| TH_NK | Greater London |
| Tibor Darvas Ltd | Buckinghamshire |
| Tibus | Ards and North Down |
| Tickbox Marketing | Bristol |
| Tickbox Systems Ltd | |
| Ticket Tailor | |
| tickMatrix.com | Hampshire |
| TICS International Ltd | Greater London |
| Tictoc Digital | Glasgow |
| TidalSense | |
| Tide Platform Ltd | |
| Tidy Design | Hampshire |
| Tidy Planet Ltd | |
| Tiedata Ltd | Derbyshire |
| Tier 2 Consulting Ltd | Hertfordshire |
| tier1 | |
| TIEVA | |
| Tig Consulting Ltd | Hertfordshire |
| TIGA | Greater London |
| Tiga Creative Marketing Ltd | Kent |
| Tiger Marketing | West Sussex |
| Tiger PC Solutions Ltd | Surrey |
| Tiki-toki | |
| Tiksom Ltd | |
| Tilda Publishing | Greater London |
| Tiller Technologies Ltd | |
| TILT Media Ltd | |
| Tilt Property Software | Newry, Mourne and Down |
| Tim Marner | |
| Time Assistant | |
| Time Digital Ltd | Kent |
| Time Electronics Ltd | Kent |
| Time Finance plc | |
| Time Technology Ltd | Surrey |
| Time-Lapse Systems | |
| Time2Talk Communications | Swansea |
| TimeOff.Management | |
| Times Higher Education | |
| Times Higher Education | |
| Timestar Developments Ltd | Tyne and Wear |
| Timestatic Ltd | |
| Timestep | Devon |
| TimeTools Ltd | West Midlands |
| Timewade | Devon |
| Timeware (UK) Ltd | Greater Manchester |
| Timico Ltd | Nottinghamshire |
| TimJonesTek | |
| Tin Soldier Web Design & SEO | Wiltshire |
| Tinderhouse Ltd | Kent |
| Tinpeas Web Design | Suffolk |