| Traditional Carriage Driving Ltd | Arts & recreation | 2017 |
| Trainee Ltd | Information & communication | 2025 |
| Training IT Ltd | Information & communication | 2015 |
| Tram Holdings Limited | Financial services | 2024 |
| Tranquillity Project Limited | Real estate | 2025 |
| Transmisia Ltd | Transport & logistics | 2021 |
| Transpeed (Europe) Limited | Information & communication | 1990 |
| Transportsw Limited | Transport & logistics | 2018 |
| Travel Connect Salisbury Limited | Transport & logistics | 2019 |
| Travel Connect Tours Ltd | Transport & logistics | 2019 |
| Travers Construction Ltd. | Construction | 2010 |
| Travis Baxter Limited | Professional & scientific | 2010 |
| Trebetherick Fields Limited | Real estate | 2021 |
| Tree Technique Ltd | Agriculture & fishing | 2006 |
| Treetop Alliance Ltd | Administrative & support | 2024 |
| Treetops (Aston Clinton) Management Company Limited | Households | 2016 |
| Treetops Thetford Road Brandon Residents Management Co. Ltd | Households | 2009 |
| Tregarrick Farm Property Management Company Limited | Households | 2009 |
| Trendy Trainers Limited | Wholesale & retail | 2010 |
| Trethowans LLP | | 2008 |
| Trethowans Trust Corporation Limited | Professional & scientific | 2021 |
| Trevett Business Services Ltd | Professional & scientific | 2023 |
| Trevett Holdings Limited | Financial services | 2018 |
| Trevoole Ltd | Administrative & support | 2021 |
| Trevor Hunns Ltd | Manufacturing | 2018 |
| Trevor Toys Limited | Real estate | 1966 |
| TRI Forces Functions Ltd | Administrative & support | 2026 |
| Triage Point Limited | Health & social care | 2024 |
| Tribal Creative Limited | Professional & scientific | 2023 |
| Tricot Ltd | Information & communication | 2025 |
| Tricrane Limited | Real estate | 1998 |
| Trikona Limited | Information & communication | 2009 |
| Trilumen Limited | Professional & scientific | 2025 |
| Trinity Accountants (UK) Limited | Professional & scientific | 2007 |
| Trinity Court Peterborough Limited | Real estate | 2025 |
| Trinity One (Leeds) Management Company Limited | Households | 2004 |
| Triple X Trading Limited | Wholesale & retail | 2004 |
| Trisonic Media Limited | Professional & scientific | 2018 |
| Tritax Taxis Ltd | Transport & logistics | 2014 |
| Tromans Medico-Legal Limited | Public administration | 2009 |
| Truan Construction Industries LLP | | 2025 |
| True Impact Engraving Ltd | Wholesale & retail | 2025 |
| True Provenance Limited | Wholesale & retail | 2020 |
| True Wood Floors Ltd | Construction | 2019 |
| Truemuse Ltd | Professional & scientific | 2025 |
| Trussell Retail Limited | Wholesale & retail | 2023 |
| Trussell Trading Limited | Other services | 2021 |
| Trustee Service Corporation Limited | Professional & scientific | 1984 |
| Truth Transport & Logistics Ltd | Transport & logistics | 2025 |
| TS Nominee One Limited | Professional & scientific | 2022 |
| TS Nominee Two Limited | Professional & scientific | 2022 |
| Tsponline Ltd | Wholesale & retail | 2025 |
| Tubbstar Franchising Limited | Professional & scientific | 2006 |
| Tube Phones Limited | Information & communication | 2005 |
| Tudor Studios RTM Company Limited | Households | 2020 |
| Turf Irrigation Services (Scotland) Limited | Construction | 1994 |
| Turkish Villa Holidays Ltd. | Real estate | 2010 |
| Turner (Winterbourne Stoke) Limited | Agriculture & fishing | 2010 |
| Turner Brothers Plastering Ltd | Construction | 2019 |
| Turners Hill (Crawley Down) Management Company Limited | Households | 2015 |
| Tuscania Publishing Ltd | Manufacturing | 2012 |
| Tusk Trust Limited | Extraterritorial | 2019 |
| Tusk Trust Trading Limited | Administrative & support | 1992 |
| Tustain Property Holdings Limited | Real estate | 2024 |
| TVS Boiler Spares Limited | Administrative & support | 2013 |
| TW Pizza Limited | Hospitality | 2010 |
| Twaseen Property Ltd | Real estate | 2024 |
| Tweakit Ltd | Wholesale & retail | 2020 |
| TWENTY20 Surveys Ltd | Professional & scientific | 2020 |
| Twentytwenty Dental Care Ltd | Health & social care | 2020 |
| Twin Axis Design Ltd | Professional & scientific | 2025 |
| Twirlrose Limited | Real estate | 1981 |
| Twizzell Limited | Wholesale & retail | 2023 |
| Tylks Limited | Wholesale & retail | 2026 |
| Tylney Investments Limited | Real estate | 1989 |
| Tysolo Limited | Real estate | 2014 |
| Tytherington Water Company Limited | Water & waste | 2000 |
| Tyttenhanger Limited | Real estate | 2007 |
| Ubiqs Property Limited | Information & communication | 2024 |
| Ubique Aviation Limited | Professional & scientific | 2025 |
| UCL Group Ltd | Financial services | 2024 |
| Uhuru Global Relief CIC | Transport & logistics | 2026 |
| UK Academies of Gymnastics Limited | Education | 2021 |
| UK Armed Forces Polo Association | Arts & recreation | 2011 |
| UK Health Drugstore Limited | Wholesale & retail | 2025 |
| UK Hobby Horse Ltd | Arts & recreation | 2025 |
| UK Kan-Do Ltd | Professional & scientific | 2023 |
| UK Maritime Consulting Ltd | Transport & logistics | 2023 |
| UK Mowers Direct Ltd | Wholesale & retail | 2020 |
| UK Protection Dogs Ltd | Other services | 2022 |
| UK Steel Buildings South Ltd | Manufacturing | 2019 |
| UK Tech Recruit Ltd | Extraterritorial | 2015 |
| UK Vending Group Limited | Wholesale & retail | 2021 |
| Uk-Hu Limited | Real estate | 2018 |
| Ukrainian Community "United" (UCU) CIC | Wholesale & retail | 2024 |
| Ultimate Luxury Limited | Hospitality | 2017 |
| Ultimate Screw Piling Ltd | Construction | 2020 |
| Ultra Class ACT Properties LLP | | 2021 |
| Uncharted Limbo Collective Limited | Arts & recreation | 2023 |
| Under Pressure - Salisbury Ltd | Manufacturing | 2014 |