| Transported by Sterling Limited | Wholesale & retail | 2020 |
| Transporttour Ltd | Transport & logistics | 2022 |
| Transporttour SRL Limited | Transport & logistics | 2025 |
| Transsheff Ltd | Transport & logistics | 2021 |
| Transtra Apparels Limited | Wholesale & retail | 2022 |
| Transtrading Limited | Professional & scientific | 2011 |
| Traptrader Ltd | Information & communication | 2020 |
| Trash Market Limited | Wholesale & retail | 2024 |
| Travel Direct Minibus Services Ltd | Transport & logistics | 2025 |
| Travel Escape Academy Limited | Education | 2025 |
| Travel to Perfection Ltd | Administrative & support | 2020 |
| Travel Tours Limited | Administrative & support | 2024 |
| Travel Training and Consultancy Ltd | Professional & scientific | 2025 |
| Travel With Spiritual Limited | Wholesale & retail | 2025 |
| Travelcircle Limited | Administrative & support | 2003 |
| Travelcord Ltd | Administrative & support | 2022 |
| Traveleyes Limited | Manufacturing | 2004 |
| Travellers Rest Consett Limited | Hospitality | 2022 |
| Travellers Taxis Ltd | Transport & logistics | 2021 |
| Travis Talent Ltd | Administrative & support | 2024 |
| Travis Wainwright Builders Limited | Construction | 2004 |
| Traxys (UK) Limited | Wholesale & retail | 1988 |
| Tray Play Toolkits Ltd | Manufacturing | 2020 |
| TRC (Holdings) Limited | Administrative & support | 2008 |
| TRC Fantasy Sports Limited | Arts & recreation | 2025 |
| TRC Media House Limited | Professional & scientific | 2021 |
| Treathaus Limited | Hospitality | 2025 |
| Treatz Sheff Ltd | Hospitality | 2017 |
| Trebarwith Strand Surf School Limited | Arts & recreation | 2026 |
| Trebbi (UK) Limited | Professional & scientific | 2002 |
| Trebbi Continuum Limited | Construction | 2017 |
| Trebbi International Limited | Professional & scientific | 2013 |
| Tree Mechanical Ltd | Construction | 2023 |
| Tree P Ltd | Hospitality | 2024 |
| Treehouse Board Game Cafe Ltd | Hospitality | 2017 |
| Treehouse Creative Ltd. | Information & communication | 2017 |
| Treeline Estates Ltd | Real estate | 2010 |
| Treestock Ltd | Information & communication | 2025 |
| Trefoil Steel Company Limited | Manufacturing | 1982 |
| Tregaron Developments Ltd | Construction | 2024 |
| Tregor Electronics Ltd | Information & communication | 2024 |
| Tregye Investments Ltd | Financial services | 2015 |
| Trek Group Limited | Financial services | 2017 |
| Trek Investments Ltd | Financial services | 2019 |
| Trek Manufacturing Limited | Manufacturing | 2021 |
| Trek Parts Limited | Wholesale & retail | 2020 |
| Trek Properties Limited | Financial services | 2020 |
| Trek Trucks Limited | Wholesale & retail | 2021 |
| Trelawny Ltd | Real estate | 2020 |
| Trelyon Avenue Management Company Limited | Households | 2019 |
| Trelyon Design Limited | Construction | 2020 |
| Trelyon Investments Limited | Hospitality | 2019 |
| Trench Properties Ltd | Real estate | 2010 |
| Trenchdare Engineering Limited | Manufacturing | 1984 |
| Trend Consult Ltd | Professional & scientific | 2023 |
| Trend Scale Ltd | Wholesale & retail | 2025 |
| Trends Wigs Limited | Other services | 2013 |
| Trendsetter’S Haven Ltd | Wholesale & retail | 2025 |
| Trendy Locks Training Academy Limited | Education | 2019 |
| Trenndy Fire & Security Ltd | Construction | 2024 |
| Trenpa Therapy Ltd | Health & social care | 2011 |
| Trent Architecture + Design Limited | Professional & scientific | 1990 |
| Trent Decorators Limited | Wholesale & retail | 1979 |
| Trent Healthcare Ltd | Health & social care | 2010 |
| Trent Insulations Limited | Extraterritorial | 1979 |
| Trent Joinery Limited | Construction | 2023 |
| Trent Regional Ophthalmic Society (Trophy) C.I.C. | Education | 2017 |
| Trent Technical and Engineering Services Ltd. | Other services | 2001 |
| Trestellar Limited | Professional & scientific | 2013 |
| Trevosa Health Limited | Health & social care | 2024 |
| TRG Care Company Limited | Professional & scientific | 2022 |
| TRI Tone Ltd | Professional & scientific | 2023 |
| Tri-Point Services Ltd | Administrative & support | 2023 |
| Tri-Sports Consultancy Limited | Construction | 2017 |
| Triangle INT Ltd | Wholesale & retail | 2025 |
| Trianglestudio Ltd | Arts & recreation | 2016 |
| Tribal Dynamics Holdings Limited | Administrative & support | 2016 |
| Tribal Dynamics Limited | Information & communication | 2005 |
| Tribal Education Limited | Education | 2001 |
| Tribal Group PLC | Education | 2000 |
| Tribal Holdings Limited | Professional & scientific | 1995 |
| Tribal Knowledge Group Limited | Information & communication | 2023 |
| Tribeka Brooklands Limited | Real estate | 2017 |
| Tribeka Developments (ASH Lane) Limited | Real estate | 2016 |
| Tribeka Developments (Woodhouse) Limited | Real estate | 2016 |
| Tribeka Developments Limited | Real estate | 2008 |
| Tribeka Holdings Limited | Real estate | 2003 |
| Tribeka Investments Limited | Real estate | 2008 |
| Tribepad Group Ltd | Financial services | 2016 |
| Tribepad Holdings Group Limited | Information & communication | 2022 |
| Tribepad Ltd | Information & communication | 2008 |
| Tribosonics Ltd | Professional & scientific | 2006 |
| Tricia Hair and Beauty Ltd | Other services | 2025 |
| Tricky Wingers Limited | Arts & recreation | 2011 |
| Tricrest Group Ltd | Hospitality | 2026 |
| Trident Design and Consultancy Ltd | Professional & scientific | 2021 |
| Trident Equine Dental Education Limited | Professional & scientific | 2019 |
| Trident PDR Limited | Wholesale & retail | 2012 |
| Trident UXO Solution Limited | Professional & scientific | 2025 |
| Trileon Assist Ltd | Professional & scientific | 2026 |