| Trafalgar House Holdings Limited | Extraterritorial | 2015 |
| Trafalgar House Investco Limited | Administrative & support | 1971 |
| Trafalgar House Pensions Administration Limited | Administrative & support | 2017 |
| Trafalgar House Serviceco Limited | Administrative & support | 1994 |
| Trafalgar House Trustees Limited | Professional & scientific | 1981 |
| Trainhgv Limited | Administrative & support | 2024 |
| Training of Significance Limited | Professional & scientific | 2013 |
| Transformational Tech Consulting Ltd | Information & communication | 2021 |
| Translate House Ltd | Professional & scientific | 2013 |
| Transvision Limited | Administrative & support | 2016 |
| Travel Clinic Farnborough Limited | Health & social care | 2015 |
| Travelista Travel and Media Ltd | Manufacturing | 2023 |
| Traxlogix Ltd | Administrative & support | 2016 |
| Tredenham House Residents Association Limited | Households | 1982 |
| Trenchard Trading Limited | Wholesale & retail | 2014 |
| Trends Logix Ltd | Information & communication | 2021 |
| Trendxmedia Ltd | Information & communication | 2017 |
| Trevista Engineering Limited | Wholesale & retail | 2006 |
| Triangle DOT Zero Ltd | Information & communication | 2023 |
| Tricon Private Ltd | Hospitality | 2022 |
| Trinity Space Technologies Ltd | Manufacturing | 2023 |
| Tripod Productions Ltd | Information & communication | 2017 |
| Trish Pomeroy Ltd | Professional & scientific | 2018 |
| Tristan Douglas Limited | Manufacturing | 2011 |
| Triumph Motor Company Limited | Professional & scientific | 1947 |
| Troupemead Limited | Real estate | 2018 |
| Trudie Nago Company Limited | Health & social care | 2013 |
| True Flooring & Developments Ltd | Construction | 2021 |
| True Pixel Ltd | Manufacturing | 2001 |
| Truffles Delight Ltd | Manufacturing | 2025 |
| Trustworthy Creations Limited | Wholesale & retail | 2021 |
| Trux Systems Ltd | Wholesale & retail | 2025 |
| TRY Ibiza Ltd | Administrative & support | 2025 |
| Tsang Property Investment Limited | Real estate | 2021 |
| Tswe Ltd | Wholesale & retail | 2019 |
| Ttca Ltd | Professional & scientific | 2002 |
| TTP Communications Limited | Professional & scientific | 2000 |
| Ttpcom Limited | Extraterritorial | 1997 |
| Tudorbank Investments Limited | Construction | 1989 |
| Tugela Trail Ltd | Wholesale & retail | 2019 |
| Tui&La Ltd | Financial services | 2025 |
| Tulip Jewels & Beauty Limited | Wholesale & retail | 2018 |
| Turbos Specialist Ltd | Wholesale & retail | 2019 |
| Turkish Razor 36 Ltd | Other services | 2024 |
| Turning Heads Ltd | Other services | 2021 |
| Tw's Hairstyling Limited | Other services | 2005 |
| Twickenham Carpentry Ltd | Construction | 2026 |
| Twickenham Craft Limited | Construction | 2014 |
| Twigs Bespoke Joinery Limited | Construction | 2023 |
| Two Park Road Management Limited | Households | 2014 |
| TWS Contracts Ltd | Administrative & support | 2007 |
| Tyneside Safety Glass Company Limited | Manufacturing | 1940 |
| U Donutz Ltd | Hospitality | 2021 |
| Ubicon Limited | Professional & scientific | 2019 |
| Ubicon Universal Holdings Limited | Financial services | 2023 |
| Ujump Ltd | Transport & logistics | 2021 |
| UK Auto Hub Limited | Wholesale & retail | 2024 |
| UK Connect Holdings Limited | Financial services | 2021 |
| UK Connect Limited | Information & communication | 2013 |
| UK Legends Cars Ltd | Arts & recreation | 2025 |
| UK Legends Cars Race Parts Ltd | Wholesale & retail | 2025 |
| UK Stephen Smith Co., Limited | Professional & scientific | 2013 |
| UK Wood Floors Limited | Manufacturing | 2001 |
| Ukause Ltd | Wholesale & retail | 2025 |
| Ultimate Contracting Ltd | Construction | 2009 |
| Ultimate Software Solutions Limited | Information & communication | 2000 |
| Ultratechnica Limited | Information & communication | 2008 |
| Uni-Plus Property Limited | Real estate | 2025 |
| Uniq Digital Ltd | Manufacturing | 2021 |
| Unique Lawns Ltd | Administrative & support | 2025 |
| Uniquiti Ltd | Other services | 2018 |
| United Silicones Limited | Manufacturing | 2002 |
| Unity in Care Limited | Health & social care | 2009 |
| Universal Gurkha Security Services Limited | Administrative & support | 2009 |
| Universal Recruitment and Training Solutions Ltd | Administrative & support | 2014 |
| UNO Heuristic Limited | Information & communication | 2016 |
| UNO Property Investment Ltd | Real estate | 2022 |
| Unoshopper Limited | Wholesale & retail | 2025 |
| Untouchable Heating Limited | Construction | 2025 |
| Upil Property Investments Limited | Real estate | 2015 |
| Urban Brew Ventures Ltd | Wholesale & retail | 2026 |
| Urim Limited | Real estate | 2022 |
| Uttar Pradesh Community Association UK CIC | Other services | 2024 |
| V&P Services Limited | Transport & logistics | 2017 |
| V9 CHH Ltd | Real estate | 2022 |
| Vainir Limited | Other services | 2024 |
| Valbex Limited | Professional & scientific | 2018 |
| Vale Editorial Services Ltd | Information & communication | 2012 |
| Valkyries Cleaning Services Ltd | Administrative & support | 2020 |
| Valyka Ltd | Construction | 2022 |
| Varshani Ltd | Hospitality | 2022 |
| Vectis Networks Limited | Information & communication | 2018 |
| Vela Tech Ltd | Information & communication | 2025 |
| Velocity Paintball Ltd | Arts & recreation | 2021 |
| Vendigital Limited | Information & communication | 2000 |
| Vendor Neutral Services Limited | Professional & scientific | 2016 |
| Venture Air Conditioning Ltd | Energy | 2017 |
| Venue Male Grooming Ltd | Other services | 2026 |
| Vera Lucia’S Salon Limited | Other services | 2023 |
| Verantis Financial Planning Ltd | Financial services | 2026 |