| Trade Hub Services Ltd | Construction | 2025 |
| Tradesmen to Forex Traders (TFT Ltd | Education | 2022 |
| Tradingstop Limited | Financial services | 2024 |
| Trak-O-Mend Holdings Limited | Real estate | 1961 |
| Trakbak Racing Limited | Arts & recreation | 1997 |
| Trans Monica Ltd | Transport & logistics | 2025 |
| Transport Arek Ltd | Transport & logistics | 2020 |
| Transpower Drives Limited | Wholesale & retail | 1982 |
| Transpower Group Limited | Wholesale & retail | 2019 |
| Travel Easy Holidays Ltd | Information & communication | 2023 |
| Treadvance Limited | Professional & scientific | 2025 |
| Tree Tech Northants Ltd | Administrative & support | 2020 |
| Trendish.Co.Uk Ltd | Wholesale & retail | 2024 |
| TRENDS2024 Limited | Wholesale & retail | 2024 |
| Trendxtra Ltd | Information & communication | 2025 |
| Trent Foods Limited | Manufacturing | 2000 |
| Tres Pilates Ltd | Arts & recreation | 2025 |
| Trevor Jolley Design LLP | | 2017 |
| Tribs Consulting Ltd | Wholesale & retail | 2021 |
| Tribs Transport Ltd | Transport & logistics | 2022 |
| Triffic Ltd | Wholesale & retail | 2020 |
| Trinity Power Services Limited | Administrative & support | 2019 |
| Trinkety Paws Limited | Wholesale & retail | 2021 |
| Tripal Group Limited | Professional & scientific | 2011 |
| Tripal International Limited | Wholesale & retail | 2004 |
| Trips on Wheels Limited | Wholesale & retail | 2023 |
| Triumphstride Limited | Professional & scientific | 1919 |
| Trixel Sport Ltd | Wholesale & retail | 2023 |
| TRL Specialist Transport Limited | Transport & logistics | 2023 |
| Trojan Ice Ltd | Wholesale & retail | 2024 |
| True Hair Collective Ltd | Other services | 2024 |
| Trueshade Interiors Ltd | Construction | 2025 |
| Truevector Ltd | Information & communication | 2024 |
| Truly Visual Productions Limited | Information & communication | 2016 |
| Trvstjaco Ltd | Wholesale & retail | 2023 |
| Tshala Shipping Ltd | Transport & logistics | 2026 |
| TTA Civils Ltd | Construction | 2021 |
| TTE Consulting Limited | Professional & scientific | 2023 |
| TU Global Ltd | Wholesale & retail | 2024 |
| Tudor Rose Packaging Limited | Administrative & support | 2005 |
| Tuitive Limited | Education | 2025 |
| TUJ1980 Ltd | Transport & logistics | 2016 |
| Tuning Academy Ltd | Wholesale & retail | 2021 |
| Turnell and Odell Limited | Manufacturing | 1943 |
| Turner Hospitality Group Limited | Hospitality | 2025 |
| TVE Investments Unlimited | Financial services | 2021 |
| TW Developments Limited | Real estate | 1989 |
| TW Stonehouse Ltd | Construction | 2024 |
| TWENTYTHREE6 Ltd | Manufacturing | 2025 |
| Twospanners Ltd | Wholesale & retail | 2021 |
| Twrmi CIC | Other services | 2020 |
| Tyers & SON Brickwork Limited | Construction | 2003 |
| Tylim Limited | Health & social care | 2012 |
| Tyme Properties Ltd | Real estate | 2023 |
| Tyme Sourcing Ltd | Administrative & support | 2024 |
| TZ Dent Limited | Wholesale & retail | 2023 |
| U&I Ltd | Real estate | 2017 |
| U-Pol Bidco Limited | Manufacturing | 2010 |
| U-Pol Limited | Manufacturing | 1949 |
| UBA Trans Ltd | Transport & logistics | 2015 |
| UE Equipment Hire Ltd | Administrative & support | 2015 |
| UE Group Holdings Ltd | Financial services | 2015 |
| UE Group Limited | Manufacturing | 2015 |
| Ugly MUG Wellingborough Limited | Hospitality | 2023 |
| UK Advanced Power Systems Ltd | Professional & scientific | 2026 |
| UK Cleaning Professionals Academic Service Limited | Water & waste | 2011 |
| UK Fastener Shop Ltd | Wholesale & retail | 2024 |
| UK Protap Limited | Hospitality | 2017 |
| UK Smile Abroad Ltd | Professional & scientific | 2026 |
| Ultimate Alliance Personnel - Deborah Ltd | Extraterritorial | 2024 |
| Ultimate Course Ltd | Manufacturing | 2022 |
| Uncle Myses Limited | Manufacturing | 2025 |
| Underground (Vinyl)Manufacturing Ltd | Manufacturing | 2017 |
| Unic Property Group Ltd | Financial services | 2026 |
| Unic Property Ltd | Real estate | 2026 |
| Unic Property Rentals Ltd | Real estate | 2026 |
| Unic Property Solutions Ltd | Professional & scientific | 2026 |
| Unic Shipping Ltd | Transport & logistics | 2019 |
| Uniflo Transport Limited | Transport & logistics | 2019 |
| Unipas Site Services Limited | Administrative & support | 2025 |
| Uniq Univers Ltd | Manufacturing | 2024 |
| Unique Healthcare Providers Ltd | Health & social care | 2017 |
| Unique Talent CIC | Public administration | 2015 |
| United Gaming Ltd | Information & communication | 2021 |
| United Progressive Homes Ltd | Real estate | 2024 |
| Universal Automotive Group Limited | Wholesale & retail | 2023 |
| Universal Engineering (Midlands) Ltd | Manufacturing | 2008 |
| Untold Story Intl Ltd | Wholesale & retail | 2020 |
| Upsys Technology Ltd | Manufacturing | 2019 |
| Upton Marina Limited | Real estate | 1987 |
| Urban Capital Limited | Real estate | 2017 |
| Urban Heath Limited | Hospitality | 2025 |
| Urban K9 Ltd | Wholesale & retail | 2026 |
| Urban OPS Indoor CQB Limited | Arts & recreation | 2025 |
| Urban Trading GRP Ltd | Wholesale & retail | 2009 |
| Ursu Bogdan Ltd | Transport & logistics | 2018 |
| Used Structural Steel Machinery Ltd | Professional & scientific | 2013 |
| Used-Machinery.Com Ltd | Wholesale & retail | 2017 |
| USS Catering & Refrigeration Equipment Limited | Other services | 1985 |
| Uttam Patel Ltd | Health & social care | 2009 |