| Turner and Turner Properties Ltd | Real estate | 2017 |
| Turner Newman Limited | Financial services | 2014 |
| Turner Properties (Oxford) Limited | Real estate | 2016 |
| Turner Properties (Oxfordshire) Lettings Limited | Households | 2023 |
| Turpin & Miller LLP | | 2010 |
| Turrill Properties Holdings Limited | Real estate | 2025 |
| Turrill Properties Limited | Real estate | 2025 |
| Turtle Rentals Ltd | Real estate | 2025 |
| Turville Estates (U.K.) Limited | Real estate | 1979 |
| Tuskers Trading Ltd | Wholesale & retail | 2026 |
| Tutie Limited | Public administration | 2024 |
| Tutoring Qualifications Limited | Education | 2024 |
| Tutors International 1 LLP | | 2014 |
| Tutors International 10 LLP | | 2017 |
| Tutors International 11 LLP | | 2018 |
| Tutors International 12 LLP | | 2018 |
| Tutors International 2 LLP | | 2014 |
| Tutors International 3 LLP | | 2014 |
| Tutors International 4 LLP | | 2014 |
| Tutors International 5 LLP | | 2014 |
| Tutors International 6 LLP | | 2014 |
| Tutors International 7 LLP | | 2014 |
| Tutors International 8 LLP | | 2014 |
| Tutors International 9 LLP | | 2017 |
| Tutors International Ltd | Education | 2009 |
| TV Link AV Ltd | Wholesale & retail | 2025 |
| Tvco Limited | Real estate | 2006 |
| Tvsh Limited | Construction | 2016 |
| Tvsn Ltd | Education | 2016 |
| TW Ludgate & SON Limited | Wholesale & retail | 2010 |
| TW0CATS Games Ltd | Information & communication | 2023 |
| TW1NS Ltd | Wholesale & retail | 2025 |
| Twenty-Nine Norham Road Limited | Households | 2009 |
| Twinkle Star Trading Ltd | Hospitality | 2022 |
| Twinlands Media Ltd | Information & communication | 2026 |
| Twinseas Limited | Education | 2015 |
| Twmt Coaching Limited | Arts & recreation | 2025 |
| Two Boys Food Ltd | Hospitality | 2019 |
| Two Boys OX3 Food Ltd | Hospitality | 2019 |
| Two Peas Studios Ltd. | Information & communication | 2026 |
| Two Wheel Dynamics Limited | Transport & logistics | 2024 |
| Twyman Investments Ltd | Financial services | 2025 |
| Ty's Solutions Ltd | Administrative & support | 2025 |
| Tylorstown Ltd | Real estate | 2025 |
| Typographic Research Unit Ltd | Other services | 2006 |
| Tyruplex Limited | Real estate | 1954 |
| U Livin Lets Limited | Real estate | 2019 |
| U Motle Ltd | Wholesale & retail | 2025 |
| U&G Consulting Ltd | Professional & scientific | 2019 |
| U-Drive Racing Ltd | Extraterritorial | 2005 |
| U-Ploid Biotechnologies Ltd | Professional & scientific | 2024 |
| U.H.Z Ltd | Wholesale & retail | 2026 |
| U.K to EU Transport Limited | Transport & logistics | 2017 |
| Ucozy Snoozy Limited | Real estate | 2018 |
| UDA (Trading) Limited | Professional & scientific | 2021 |
| Uddins Brothers Ltd | Real estate | 2025 |
| Udjat C.I.C. | Information & communication | 2021 |
| Uense Limited | Wholesale & retail | 2018 |
| UEV Holdings Ltd | Financial services | 2024 |
| UEV Tech Ltd | Wholesale & retail | 2024 |
| UEV Technologies Ltd | Wholesale & retail | 2024 |
| UFC Services Ltd | Information & communication | 2023 |
| UGC JV Pension Trustees Limited | Extraterritorial | 1997 |
| UGC Pension Trustees Limited | Extraterritorial | 1987 |
| UGC Retirement Benefits Trustees Limited | Extraterritorial | 1985 |
| UGC(2015) Limited | Professional & scientific | 2015 |
| Uhuru Collective Holdings Limited | Real estate | 2010 |
| UK Aerospace Limited | Transport & logistics | 2007 |
| UK Bridge Education Limited | Administrative & support | 2012 |
| UK China Culture and Education Foundation Limited | Education | 2018 |
| UK China Energy Association Limited | Energy | 2016 |
| UK China Talent Promotion Association Ltd | Administrative & support | 2024 |
| UK Confederation of Futebol DE Salao Limited | Arts & recreation | 1998 |
| UK Grinding and Machine Services Limited | Manufacturing | 2015 |
| UK Holiday Travel Limited | Administrative & support | 2018 |
| UK Industrial Roofing Ltd | Construction | 2024 |
| UK Japan Hybrid Ltd | Wholesale & retail | 2024 |
| UK Labs Group Ltd | Administrative & support | 2024 |
| UK Motels Limited | Hospitality | 2025 |
| UK Officer Ltd | Extraterritorial | 2019 |
| UK Pride Shop Ltd | Wholesale & retail | 2026 |
| UK Rics Limited | Professional & scientific | 2025 |
| UK Siam Education Ltd | Education | 2024 |
| UK Tilehub Ltd | Wholesale & retail | 2026 |
| UK Timber Merchants Ltd | Wholesale & retail | 2026 |
| UK Vibes Music Ltd | Information & communication | 2025 |
| UK Water Dispensers Ltd | Administrative & support | 2025 |
| UK WS Import Ltd | Wholesale & retail | 2019 |
| Ukchina Connection Ltd | Education | 2009 |
| Ukcitytour Ltd | Administrative & support | 2024 |
| Ukibya Limited | Wholesale & retail | 2015 |
| Ukshophive Ltd | Wholesale & retail | 2025 |
| Ukti | Arts & recreation | 2019 |
| Ukvanspares Ltd | Wholesale & retail | 2026 |
| Ulbrry Ltd | Financial services | 2021 |
| Ulladulla Films LLP | | 2025 |
| ULO Properties Ltd | Real estate | 2020 |
| Ultra Property Group Ltd | Hospitality | 2025 |
| Ultrabyte Ltd | Extraterritorial | 2022 |
| Ultromics Limited | Health & social care | 2017 |