| Trinity Catering Engineers Limited | Extraterritorial | 2006 |
| Trinity Court and Minster Court Management Co. Limited | Households | 1989 |
| Trinity Hairdressing Boutique Ltd | Other services | 2026 |
| Trinity Lets Ltd | Real estate | 2021 |
| Trinity Marketing Limited | Professional & scientific | 2018 |
| Trinity Quarters Ltd | Real estate | 2023 |
| Trinity World Properties Ltd | Real estate | 2024 |
| Trio International Ltd | Wholesale & retail | 2024 |
| Tripay Systems Ltd | Information & communication | 2026 |
| Triple a Cafe Ltd | Hospitality | 2023 |
| Triple a Holdings (South East) Ltd | Financial services | 2025 |
| Triple CEE Ltd | Wholesale & retail | 2023 |
| Triple SSS Cars Ltd | Wholesale & retail | 2020 |
| Triple SSS Transport Ltd | Transport & logistics | 2025 |
| Tripple M Ltd | Health & social care | 2019 |
| Triptych Payroll Limited | Administrative & support | 2022 |
| Trish Burns Ltd | Health & social care | 2025 |
| Trish Hospitality Limited | Hospitality | 2016 |
| Tristan Baker Limited | Arts & recreation | 2000 |
| Tristan Gillen Ltd | Administrative & support | 2024 |
| Tristars Consultants Limited | Professional & scientific | 2023 |
| Tristis Properties Limited | Construction | 2017 |
| Tritec Systems Limited | Information & communication | 1991 |
| Triton Investment Services (UK) Limited | Professional & scientific | 2017 |
| Triumphands Care Limited | Other services | 2024 |
| Trixsea Ltd | Professional & scientific | 2017 |
| Troika Labs Limited | Information & communication | 2021 |
| Trojan Corporate Services Ltd | Manufacturing | 2022 |
| Trolly of Treasures Ltd | Wholesale & retail | 2024 |
| Trophyman Supplies Limited | Manufacturing | 1991 |
| Tropic Bar Ltd | Hospitality | 2016 |
| Trotswood Limited | Professional & scientific | 2024 |
| Trowel & Hawk Ltd | Construction | 2011 |
| Troy Accounting Consultancy Ltd | Professional & scientific | 2019 |
| Troy Accounting Limited | Professional & scientific | 2016 |
| Troy Training Sparks Ltd | Administrative & support | 2019 |
| Trst Management Ltd | Extraterritorial | 2021 |
| Truckdav Ltd | Transport & logistics | 2019 |
| Trudie Community Events C.I.C. | Health & social care | 2021 |
| True Cleaners Ltd | Administrative & support | 2019 |
| True Level Scaffolding Ltd | Construction | 2022 |
| True Pubs & Bars Ltd | Hospitality | 2025 |
| True Target Limited | Financial services | 2023 |
| Truelight UK Limited | Wholesale & retail | 2026 |
| Trueline Go Ltd | Transport & logistics | 2024 |
| Truestellar Ltd | Administrative & support | 2023 |
| Truestone Software Ltd | Information & communication | 2025 |
| Truevote Limited | Professional & scientific | 1990 |
| Truly Unique Ltd | Administrative & support | 2017 |
| Trumpf Laser UK Limited | Manufacturing | 1996 |
| Trusk Civil Engineering Limited | Construction | 2002 |
| Trusolv Business Recovery Limited | Professional & scientific | 2022 |
| Trusolv Limited | Professional & scientific | 2014 |
| Trusolv Recovery Limited | Professional & scientific | 2022 |
| Trust Safety Services Limited | Professional & scientific | 2018 |
| Trust Tegg Group Limited | Financial services | 2023 |
| Trust Tegg Limited | Professional & scientific | 2023 |
| Trusted Airport Transfers Ltd | Transport & logistics | 2025 |
| Trustins Building Maintenance Limited | Construction | 2019 |
| Trustins Building Services Limited | Construction | 2016 |
| Trustins Holdings Ltd | Real estate | 2026 |
| Trustpoint Accounting Services Ltd | Professional & scientific | 2025 |
| Trusty Tufty Ltd | Professional & scientific | 2014 |
| Truvox International Limited | Manufacturing | 1962 |
| Trybek Construction Limited | Construction | 2017 |
| Trygar Engineering Ltd | Manufacturing | 2002 |
| Trygar Holdings Limited | Professional & scientific | 2009 |
| Trykoda Ltd | Information & communication | 2026 |
| TS Group International Limited | Manufacturing | 1999 |
| TS Pumps Limited | Manufacturing | 2018 |
| TS Supplier UK Limited | Wholesale & retail | 2023 |
| TSA Express Ltd | Transport & logistics | 2016 |
| TSC Catering Limited | Hospitality | 2026 |
| TSC Maintenance Services Ltd | Construction | 2024 |
| Tscg Enterprises Ltd | Health & social care | 2021 |
| TSI Turbo Service International Limited | Manufacturing | 2012 |
| TSM Pumps LLP | | 2003 |
| Tsrh Limited | Real estate | 2014 |
| TST Electric Ltd | Construction | 2025 |
| Tswa Limited | Real estate | 2020 |
| TT Brothers Builders Ltd | Construction | 2025 |
| TT Fitness Consultancy CIC | Arts & recreation | 2024 |
| TT Rigging Limited | Manufacturing | 2008 |
| TT YY RR Ltd | Construction | 2026 |
| Ttca Services Limited | Construction | 2018 |
| Ttdi Ltd | Hospitality | 2025 |
| Ttext Ltd | Professional & scientific | 2021 |
| TTJ Ventures Ltd | Transport & logistics | 2025 |
| TTR Property Ltd | Real estate | 2011 |
| TTV Properties Limited | Extraterritorial | 2025 |
| TTZ Logistic Ltd | Transport & logistics | 2018 |
| TUB Club Limited | Professional & scientific | 2005 |
| Tucker & Munday Limited | Transport & logistics | 2003 |
| Tucker Joinery Limited | Manufacturing | 2013 |
| Tuder Nelthorpe Consultancy Ltd | Professional & scientific | 2024 |
| Tudor Wheels Ltd | Manufacturing | 2012 |
| Tudorfine Limited | | 1973 |
| Tugar Marine Services Ltd | Professional & scientific | 2018 |
| Tuhid Cars Limited | Transport & logistics | 2020 |
| TUI Navure Transport Ltd | Transport & logistics | 2026 |