| Name | Region |
|---|---|
| True Capital Ltd | |
| True Digital Ltd | |
| True Track Software Ltd | |
| Truebyte Ltd | East Sussex |
| TrueLayer | Greater London |
| TrueNorth IT | |
| TrueSight Ventures | Surrey |
| TrueWeb Pro Ltd | |
| Trumpet | |
| Trumphurst Ltd | Shropshire |
| Trunk | |
| TrunkBBI | |
| Truphone Ltd | Greater London |
| TruRating | |
| Trust Distribution Ltd | Greater Manchester |
| Trust Elevate | |
| Trust Networks Ltd | Hertfordshire |
| Trust Payments | |
| Trustable | |
| Trustco plc | East Sussex |
| Trusted Firmware | |
| Trusted IT | Derbyshire |
| TrustedReviews Ltd | Greater London |
| Trustico Online Ltd | Greater London |
| TrustID | |
| Trustonic | Cambridgeshire |
| Trusty.Digital | |
| TruTac Ltd | West Midlands |
| Truth ISC Technology and Security Consultancy Ltd | Greater London |
| Truver | |
| Truzo | |
| TryHackMe | |
| Trymerra.ai | |
| TSG Software | Surrey |
| TSM Audio-Media | |
| TSM Ltd | Cambridgeshire |
| TST | Cheshire |
| TT Electronics plc | Surrey |
| TT Games Studios | Cheshire |
| TT Software Ltd | Channel Islands |
| TTNC Ltd | Essex |
| TTOY Digital Ltd | |
| TTT Global UK | |
| Tucano Solutions | West Yorkshire |
| Tug | |
| Tulipshare Capital, LLC | |
| TulipTech | |
| Tumbridge Data Systems | |
| Tumelo | |
| Tunbridge Studio Ltd | Greater London |