| Trevents Ltd | Professional & scientific | 2026 |
| Trevi Capital Ltd | Financial services | 2025 |
| Treytech Limited | Wholesale & retail | 2021 |
| Triad Group PLC | Information & communication | 1988 |
| Triad Special Systems Limited | Extraterritorial | 1995 |
| Trial Pits Ltd | Information & communication | 2015 |
| Triang Consultancy Services Limited | Professional & scientific | 2016 |
| Tribes Research Limited | Professional & scientific | 2013 |
| Trinest Ltd | Real estate | 2022 |
| Trinity Infinity Ltd. | Health & social care | 2016 |
| Trinity Trust Team | Education | 2012 |
| Trinkfluss Wines Ltd | Wholesale & retail | 2024 |
| Trio Arts Academy Ltd | Arts & recreation | 2025 |
| Trizec Ltd | Construction | 2023 |
| Trueinvivo Limited | Manufacturing | 2014 |
| Trunk Bums Ltd | Wholesale & retail | 2025 |
| Trust Hire Recruitment Limited | Administrative & support | 2023 |
| Trustco Capital Ltd. | Professional & scientific | 2013 |
| Trusted Data Community Limited | Information & communication | 2024 |
| TSD Homes Limited | Construction | 2024 |
| Tsdc-Group Ltd | Extraterritorial | 2026 |
| Tsdc-Uk Ltd | Wholesale & retail | 2026 |
| TST Live LLP | | 2016 |
| TTP Autumn Limited | Arts & recreation | 2018 |
| TTP Productions Limited | Arts & recreation | 2019 |
| TTP Shows Limited | Arts & recreation | 2023 |
| TTP Summer Limited | Arts & recreation | 2023 |
| TTP Winter Shows Limited | Arts & recreation | 2024 |
| TTR Holdings Ltd | Financial services | 2021 |
| Tubbs Associates Limited | Professional & scientific | 2010 |
| Tulla IT Consulting Ltd | Information & communication | 2007 |
| Tunridge Construction LLP | | 2025 |
| Tunridge Holdings Ltd | Real estate | 2018 |
| Tunridge Property Management LLP | | 2023 |
| Turner Cardiology Limited | Professional & scientific | 2024 |
| Twenty Eight Marshall Road Management Limited | Households | 1981 |
| TWENTYONE10 Ltd | Wholesale & retail | 2017 |
| Twentyshire Investments Limited | Real estate | 1963 |
| TWH Engineering Limited | Wholesale & retail | 2025 |
| Twist Sondes Limited | Construction | 2011 |
| Twist Three Limited | Construction | 2015 |
| Two Green Beans Limited | Manufacturing | 2012 |
| Two Mares Ltd | Wholesale & retail | 2018 |
| Twyzle Limited | Information & communication | 2020 |
| Ubik Investments Ltd | Real estate | 2012 |
| UK Dealer Parts Ltd | Wholesale & retail | 2026 |
| UK Pickleball Store Ltd | Wholesale & retail | 2026 |
| UK Property Solutions (Down Cottage) Limited | Construction | 2020 |
| UK2LEARN Guardianship Limited | Education | 2018 |
| UK2LEARN Ltd | Professional & scientific | 2025 |
| Ukrainian Snack to Snack Limited | Manufacturing | 2024 |
| Ultimate Sounds Ltd | Wholesale & retail | 2020 |
| Umedia Entertainment Ltd. | Information & communication | 2012 |
| Unbound Coaching & Consulting Limited | Other services | 2022 |
| Underdog Sports Marketing Ltd | Professional & scientific | 2018 |
| Underground Mapping Limited | Extraterritorial | 2001 |
| Undertoad Charters Limited | Administrative & support | 2025 |
| Undeveloper Ltd | Information & communication | 2014 |
| Unily Group Limited | Information & communication | 2013 |
| Unily Limited | Information & communication | 2005 |
| Unimenta Ltd. | Education | 2009 |
| Unit 3 Miltons Yard Limited | Construction | 2006 |
| Universite Europeenne LLP | | 2009 |
| Untitled Management Limited | Wholesale & retail | 2013 |
| Upstream Arcade Ltd | Information & communication | 2020 |
| Uptegral Limited | Construction | 2012 |
| V Integrity Limited | Professional & scientific | 2026 |
| V Kids Ltd | Health & social care | 2023 |
| V P Olisa Associates Limited | Professional & scientific | 2017 |
| Vaccine Formulation Institute Limited | Health & social care | 2012 |
| Valor Development Ltd | Professional & scientific | 2021 |
| Valor Finance Services Ltd | Administrative & support | 2021 |
| Value Capital Limited | Financial services | 2003 |
| Van Arnhem Nursery Limited | Agriculture & fishing | 2002 |
| Van Tongeren International Limited | Construction | 1971 |
| Vangalamman Ltd | Hospitality | 2024 |
| Vanity FUR Dog Grooming Limited | Other services | 2019 |
| Vannmoor Engineering Limited | Manufacturing | 1997 |
| Vanoc Consulting Ltd | Information & communication | 2011 |
| Vantage Publishing Limited | Information & communication | 2005 |
| Vapedirect Ltd | Wholesale & retail | 2019 |
| Varno Mesto Ltd | Information & communication | 2022 |
| Veilkin Ltd | Information & communication | 2026 |
| Vendoro Distribution Ltd | Manufacturing | 2024 |
| Venu 1 Limited | Real estate | 2023 |
| Veronica Robin Lettings Ltd | Real estate | 2021 |
| Versol Ltd | Professional & scientific | 2015 |
| Vertax Wind Ltd. | Professional & scientific | 2007 |
| Vertiports Ltd | Construction | 2025 |
| Vestega Limited | Professional & scientific | 2020 |
| Vevox Holdings Limited | Financial services | 2025 |
| Vevox Limited | Information & communication | 2014 |
| Viadnode Hospitality Ltd | Hospitality | 2024 |
| Vibe Tribe Coaching Ltd | Health & social care | 2024 |
| Victoria & Mayfair Offices Ltd | Real estate | 2024 |
| Victory Construction Limited | Construction | 1994 |
| Vigla Ltd | Professional & scientific | 2010 |
| Vincancan Ltd | Wholesale & retail | 2021 |
| Viridian Consultants Limited | Professional & scientific | 2014 |
| Viscozip Limited | Professional & scientific | 2012 |