| Trubasil Properties Ltd | Real estate | 2025 |
| Truck Care Services Oxfordshire Ltd | Professional & scientific | 2026 |
| Truckcare Services Banbury Ltd | Professional & scientific | 2026 |
| Truckcare Services Ltd | Wholesale & retail | 2018 |
| Trucklineuk Ltd | Wholesale & retail | 2011 |
| Truleaf Farm Ltd | Agriculture & fishing | 2019 |
| Trusted Funeral Services Ltd | Administrative & support | 2025 |
| Tstc Limited | Administrative & support | 2011 |
| TT Stadium Solutions Ltd | Wholesale & retail | 2023 |
| Ttaylor’S Engineering Ltd | Professional & scientific | 2022 |
| Tuberosa Ltd | Administrative & support | 2023 |
| Tudor Hall School | Education | 1994 |
| Tudor Hall School Enterprises Limited | Hospitality | 2011 |
| Tudor House Lettings Ltd | Hospitality | 2023 |
| Tudorland Playground Limited | Arts & recreation | 2024 |
| Tugo & Partners Limited | Professional & scientific | 2025 |
| Tugo Holdings Limited | Hospitality | 2019 |
| Tunnel Sensors Limited | Extraterritorial | 2005 |
| Turat Limited | Hospitality | 2020 |
| Turf Tracker Ltd | Professional & scientific | 2022 |
| Turkish Barber Ltd | Other services | 2017 |
| Turneys Limited | Agriculture & fishing | 1979 |
| Turnock Associates Limited | Professional & scientific | 2012 |
| Turnstone Ecology Ltd | Professional & scientific | 2010 |
| Turpin Smale Catering Consultants Ltd | Professional & scientific | 1988 |
| Turweston Flying Club Limited | Education | 2009 |
| Tustain Carriers Ltd | Transport & logistics | 2022 |
| Tuthill Holdings Limited | Financial services | 2017 |
| Tuvey Properties Ltd | Real estate | 2019 |
| TW22 Ltd | Information & communication | 2022 |
| TWE Group Holdings Limited | Financial services | 2023 |
| TWE Logistics Limited | Transport & logistics | 2007 |
| Twenty Two Financial Services Ltd | Professional & scientific | 2021 |
| Twisted Tree Brewery Ltd | Manufacturing | 2023 |
| Two by Simon Smith Ltd | Other services | 2022 |
| Two Mills Consulting Limited | Professional & scientific | 2024 |
| TWW Cleaning Ltd | Administrative & support | 2021 |
| Twyford Farms Limited | Extraterritorial | 1961 |
| TYM Spedition Ltd | Transport & logistics | 2022 |
| Tyme Solutions Ltd | Professional & scientific | 2021 |
| Tynan Barrett Ltd | Construction | 2025 |
| Ubiquity Financial Direction Limited | Professional & scientific | 2000 |
| Ucalupu Limited | Transport & logistics | 2024 |
| Ucatimofticiuc Limited | Transport & logistics | 2018 |
| UFH Solutions Limited | Wholesale & retail | 2017 |
| UK AD Services Ltd | Professional & scientific | 2023 |
| UK Language Centres Ltd | Education | 2000 |
| UK Profile Components Limited | Manufacturing | 2005 |
| Ukhk Parts Limited | Wholesale & retail | 2013 |
| Ultimate FIX Ltd | Construction | 2018 |
| Ultra SCM Ltd | Information & communication | 2023 |
| Ultra Tanning Studio Ltd | Other services | 2022 |
| Uluntu Social Work Consultancy Ltd | Health & social care | 2019 |
| UMA Casa Portuguesa Ltd | Wholesale & retail | 2024 |
| Umbriel Consulting Limited | Information & communication | 2009 |
| Umhoefer's Analysis Ltd | Professional & scientific | 2025 |
| Unexplored Films Ltd | Information & communication | 2020 |
| Unicorn Oxon Limited | Construction | 2016 |
| Unifi Engineering Services Limited | Professional & scientific | 2017 |
| Uniform Express Limited | Wholesale & retail | 2004 |
| Uninexus Limited | Professional & scientific | 2016 |
| Unique Building Maintenance Ltd | Construction | 2014 |
| Unique House Developments Ltd | Construction | 2020 |
| Unique Jewellers Ltd | Manufacturing | 2025 |
| Unit 4 Barrington Limited | Transport & logistics | 2024 |
| Unit 51 Ltd. | Financial services | 2020 |
| Unite the Trades Ltd | Construction | 2025 |
| Unitech Oxon Limited | Manufacturing | 2001 |
| United Bats Ltd | Manufacturing | 2026 |
| United Medical Property Ltd | Real estate | 2010 |
| Unitread Limited | Wholesale & retail | 2023 |
| Unloaded Limited | Professional & scientific | 2005 |
| Unspun Textiles Ltd | Manufacturing | 2018 |
| Unter Limited | Health & social care | 2008 |
| UPD25 Ltd | Manufacturing | 2026 |
| Upraise Consulting Ltd | Professional & scientific | 2023 |
| Upright Scaffolding Specialists Ltd | Construction | 2015 |
| Upton Estate Trustees 1 Limited | Financial services | 2025 |
| Upton Estate Trustees 2 Limited | Financial services | 2025 |
| Upton Park Services Ltd | Manufacturing | 2025 |
| Upwhirl Ltd | Professional & scientific | 2019 |
| Upyourgamefitness Limited | Arts & recreation | 2022 |
| Urban Brunch Limited | Arts & recreation | 2022 |
| Urban Planning Limited | Professional & scientific | 2022 |
| Urban Route Ltd | Transport & logistics | 2025 |
| Urban Spice Bistro and Tapas Ltd | Hospitality | 2024 |
| USE My Noodle Ltd | Information & communication | 2024 |
| Uszynska Car Automotive Ltd | Wholesale & retail | 2022 |
| UV Integration Limited | Extraterritorial | 2005 |
| V Bar Foods Ltd | Extraterritorial | 2024 |
| V Care Physiotherapy Clinic Ltd | Health & social care | 2025 |
| Vacmotion Ltd | Wholesale & retail | 2023 |
| Valiprosop Construction Ltd | Construction | 2019 |
| Valla Land Limited | Real estate | 2025 |
| Valla Property Limited | Real estate | 2023 |
| Valleyton Limited | Hospitality | 2026 |
| Value Vault Online Ltd | Wholesale & retail | 2025 |
| Vama Property Group Ltd | Real estate | 2024 |
| Vance Consultancy Ltd | Professional & scientific | 2023 |
| Vanessa Fallon Limited | Professional & scientific | 2015 |