| Traidar Ltd | Information & communication | 2025 |
| Transformation Development Ltd | Households | 2025 |
| Transformation Development Partnership LLP | | 2008 |
| Transiair Kool Limited | Professional & scientific | 1991 |
| TREBLE7 Property Group Ltd | Real estate | 2021 |
| Trebleway Limited | Transport & logistics | 1983 |
| Trebortech Limited | Construction | 2026 |
| Treetops Play CIC | Health & social care | 2024 |
| Trenchard Ltd | Real estate | 2022 |
| Trevor Benton Construction Limited | Construction | 1984 |
| Trevor Benton Group Limited | Financial services | 1989 |
| Trident Carpentry & Construction Services Limited | Construction | 2013 |
| Trigger-Wheels Limited | Wholesale & retail | 2007 |
| Trimaxion Ltd | Information & communication | 2025 |
| Trinity Close Management Company Limited(The) | Other services | 1967 |
| Trinity Hall Management Limited | Real estate | 2006 |
| Trinity Stays Aberdeen Limited | Real estate | 2025 |
| Trinity Stays Limited | Real estate | 2024 |
| Trinity Stays Services Limited | Administrative & support | 2023 |
| Trinity Stays Short Term Lettings Limited | Wholesale & retail | 2020 |
| Troy Dudley Plumbing Ltd | Construction | 2023 |
| Truelink Limited | Administrative & support | 1995 |
| Truffle House Limited | Wholesale & retail | 2017 |
| Truffle MAN Limited | Wholesale & retail | 2003 |
| Trumpington Place Management Company Limited | Households | 2013 |
| Trya Globe Culture & Education Ltd | Education | 2025 |
| Tsien (U.K.) Limited | Manufacturing | 1989 |
| TSM Offshore Ltd | Other services | 2022 |
| Ttsols Ltd | Professional & scientific | 2018 |
| Tubetrain Limited | Manufacturing | 2016 |
| Tuck Property Maintenance Limited | Households | 2021 |
| Tully International Ltd | Transport & logistics | 2025 |
| Turner Bros Groundworks Ltd | Construction | 2013 |
| Turquoise Tooth Technology Ltd | Information & communication | 2007 |
| Turvill Electrical Limited | Construction | 2021 |
| TVC Cleaning Ltd | Administrative & support | 2026 |
| Twentypence 2000 Limited | Wholesale & retail | 2000 |
| Twickenham Court Residents Association Limited | Households | 1990 |
| Two County Storage Solutions Limited | Real estate | 2017 |
| Tyres 2 U (ELY) Ltd | Wholesale & retail | 2018 |
| U.K. Truck and Plant Sales Ltd. | Water & waste | 2008 |
| Ubiety Technologies Limited | Professional & scientific | 2023 |
| Ucogni Ltd | Information & communication | 2026 |
| Udyfoods 360 Limited | Hospitality | 2025 |
| UK Fixings (Southern) Limited | Wholesale & retail | 2010 |
| UK Floor Sanding Supplies Limited | Administrative & support | 2010 |
| UK Outboards Ltd | Wholesale & retail | 2015 |
| UK Pellets Ltd | Wholesale & retail | 2022 |
| Ukqs Consulting Limited | Administrative & support | 2025 |
| Ulva GRP Ltd | Manufacturing | 2015 |
| Ulva Holdings Ltd | Financial services | 2019 |
| Ulva Insulation Systems Ltd | Manufacturing | 2000 |
| Ulva International Limited | Administrative & support | 2008 |
| Uncle Paul Ltd | Hospitality | 2021 |
| Unfolding Musical Development UK Limited | Arts & recreation | 2025 |
| Unicorn Marketing Consultants Ltd | Professional & scientific | 2018 |
| Unika Fruits Ltd | Wholesale & retail | 2019 |
| Union Park Management Company Limited | Other services | 2004 |
| United Build Works Limited | Construction | 2019 |
| United Kingdom Friesian Horse Studbook Limited | Other services | 2023 |
| United Plumbing & Heating (Cambs) Limited | Construction | 2019 |
| Unityfit Ltd | Arts & recreation | 2024 |
| Universal Database Ltd | Manufacturing | 2008 |
| Untaxing Limited | Information & communication | 2022 |
| UP Alpha Limited | Hospitality | 2023 |
| Upshot Enterprises Ltd | Information & communication | 2010 |
| Upshot Investments LLP | | 2011 |
| Upshot Trading Limited | Information & communication | 2011 |
| Uptempo Events Ltd | Administrative & support | 2024 |
| Upwood Property Investments Limited | Real estate | 2019 |
| UTT Group Ltd | Financial services | 2022 |
| V Cool Solutions Ltd | Construction | 2023 |
| Valuminium Limited | Construction | 2013 |
| Vanhulle Dance Theatre CIC | Education | 2019 |
| Varsity Property Partners Limited | Hospitality | 2025 |
| Vaxcare Hub Ltd | Health & social care | 2022 |
| Vazir Ltd | Transport & logistics | 2025 |
| Vcdc Trading Ltd | Agriculture & fishing | 2024 |
| Vellam Metals Limited | Administrative & support | 2014 |
| Velocity Trades Limited | Wholesale & retail | 2023 |
| Velox Consulting Ltd | Information & communication | 2016 |
| Velvet Retreat Ltd | Real estate | 2025 |
| Verafrank AJI Limited | Health & social care | 2013 |
| Versio Vita Ltd | Information & communication | 2019 |
| Vertex Design Ltd | Professional & scientific | 2015 |
| Vesko Ltd | Wholesale & retail | 2025 |
| Vetas Limited | Extraterritorial | 2007 |
| Veterinary Vista Ltd | Professional & scientific | 2025 |
| VI Catering Littleport Limited | Hospitality | 2026 |
| Vigilant Software Limited | Information & communication | 2006 |
| Vikafurniture Ltd | Wholesale & retail | 2021 |
| Village Live Records Ltd | Wholesale & retail | 2017 |
| Villiva Ltd | Administrative & support | 2024 |
| Vincent Property Services Limited | Construction | 2019 |
| Vintex Mega Services Ltd | Financial services | 2026 |
| Virizion Services Ltd | Professional & scientific | 2018 |
| Virtual Earth Design Ltd | Professional & scientific | 2026 |
| Virtual Salon Services Limited | Extraterritorial | 2016 |
| Virtualfruit Ltd | Administrative & support | 2024 |
| Visit Limited | Information & communication | 2012 |