| Tufail Legal Ltd | Professional & scientific | 2012 |
| Tulaga Springs Ltd | Information & communication | 2025 |
| Tulip and Twine Floral Design Ltd | Wholesale & retail | 2023 |
| Tulip Homes Ltd | Real estate | 2016 |
| Tumi Healthcare P2Y Limited | Health & social care | 2021 |
| TUR8O Ltd | Extraterritorial | 2016 |
| Turing Global Innovations Ltd | Information & communication | 2021 |
| Turnbull and Walker Limited | Extraterritorial | 2026 |
| Turni Limited | Real estate | 2020 |
| Turnip Ltd | Real estate | 2022 |
| Turquoise Sea Limited | Extraterritorial | 2026 |
| Tusa Electrical Ltd | Construction | 2022 |
| Tushar LAD Ltd | Financial services | 2023 |
| Tutelar Limited | Public administration | 2022 |
| TV Shopping International Limited | Wholesale & retail | 2008 |
| Twenty 13 Design Ltd | Professional & scientific | 2013 |
| Twenty 2 Design Ltd | Professional & scientific | 2024 |
| Twenty to Two Limited | Wholesale & retail | 2013 |
| Twenty Twenty Consulting Limited | Administrative & support | 2016 |
| Twilko Management Services Limited | Professional & scientific | 2011 |
| Twine Projects Limited | Professional & scientific | 2019 |
| Twingo Ltd | Extraterritorial | 2012 |
| Twisted (SAC) Limited | Financial services | 2026 |
| Two Johns Electrical Ltd | Construction | 2026 |
| Two Little Mice Ltd | Manufacturing | 2017 |
| Twos Company Bakery Limited | Manufacturing | 2024 |
| TWR Associates Limited | Professional & scientific | 2023 |
| Tyler Ambridge Limited | Extraterritorial | 2025 |
| Tyneside Consulting Services Limited | Administrative & support | 2018 |
| Type B Solutions Limited | Administrative & support | 2025 |
| Tyto Consulting Services Ltd | Administrative & support | 2003 |
| Tywest Investments Limited | Professional & scientific | 1984 |
| U Coach ME Limited | Other services | 2013 |
| U LET Limited | Real estate | 2001 |
| Ucanca Valley Ltd | Administrative & support | 2019 |
| UDB Fit Ltd | Arts & recreation | 2020 |
| Udun for Trading Ltd | Wholesale & retail | 2022 |
| UGS (Harrogate) Limited | Real estate | 1998 |
| UK Engagement Ring Company Ltd | Manufacturing | 2024 |
| UK Gaming Solutions Limited | Arts & recreation | 2013 |
| UK Giclee Printing Ltd | Manufacturing | 2023 |
| UK Lexicon Ltd | Education | 2025 |
| UK Made Limited | Extraterritorial | 2011 |
| UK Mortgage Experts Ltd | Financial services | 2015 |
| UK Risk Assessments Ltd | Administrative & support | 2025 |
| UK Specialist Services Limited | Administrative & support | 2014 |
| UK Toy Deals Ltd | Wholesale & retail | 2021 |
| UK Wedding Ring Company Ltd | Manufacturing | 2024 |
| Ukfc Co. Ltd | Wholesale & retail | 2021 |
| UKG Trustees Limited | Administrative & support | 2022 |
| ULA Beauty Limited | Wholesale & retail | 2024 |
| Ulta Ltd | Information & communication | 2022 |
| Ultimate Languages Limited | Professional & scientific | 2018 |
| Ultimate Rally Limited | Arts & recreation | 2015 |
| Ultimoore Limited | Extraterritorial | 2022 |
| Ultimorph Limited | Information & communication | 2024 |
| Ultra Properties Yorkshire Limited | Real estate | 2023 |
| Ultrabuild (Yorkshire) Ltd | Construction | 2018 |
| Ultramill Limited | Manufacturing | 2013 |
| Ulysses Tax Consulting Ltd | Professional & scientific | 2024 |
| Umbrella Property Group Limited | Real estate | 2005 |
| UN1VERSAL Limited | Extraterritorial | 2021 |
| Unamas Investments Limited | Financial services | 2020 |
| Unboxed Projects Limited | Professional & scientific | 2025 |
| UNC Harrogate Ltd | Arts & recreation | 2025 |
| Uncommon Opco Limited | Professional & scientific | 2025 |
| Underground Bakery Limited | Wholesale & retail | 2021 |
| Unicorn Competitions Ltd | Arts & recreation | 2022 |
| Unified Security Consulting Ltd | Information & communication | 2019 |
| Unil C9 Limited | Administrative & support | 2009 |
| Union Properties (Yorkshire) Limited | Professional & scientific | 2006 |
| Union Woodshop Limited | Extraterritorial | 2012 |
| Unique DOT COM Ltd | Extraterritorial | 2012 |
| Unique N Classic Jewels Ltd | Wholesale & retail | 2025 |
| Unique Team Wear Ltd | Wholesale & retail | 2023 |
| Unique Transportation Group Ltd | Transport & logistics | 2019 |
| Uniquely YOU Consultancy Ltd | Professional & scientific | 2024 |
| UNIT19.SHOP Limited | Wholesale & retail | 2025 |
| United Bank of Carbon | Other services | 2009 |
| United Bank of Carbon Trading Limited | Extraterritorial | 2008 |
| United Engineering Leadership Company for Engineering Consultations Ltd | Professional & scientific | 2013 |
| United Global Marketing Ltd | Wholesale & retail | 2022 |
| United Tributaries Ltd | Wholesale & retail | 2021 |
| Unity Aviation Holdings Limited | Professional & scientific | 1987 |
| Unity Commerace Ltd | Wholesale & retail | 2025 |
| Unity Land LLP | | 2017 |
| Unity Resourcing Ltd | Administrative & support | 2014 |
| Universal Experts Consulting Limited | Professional & scientific | 2011 |
| Universal Hydro Systems Ltd | Agriculture & fishing | 2014 |
| Universal Student Living Limited | Hospitality | 2012 |
| Unseen Forms Limited | Information & communication | 2022 |
| Unstructured Ltd | Professional & scientific | 2024 |
| Untold Agency Limited | Professional & scientific | 2014 |
| Untucked and Unlaced Ltd | Manufacturing | 2025 |
| UNW Trading Co Ltd | Wholesale & retail | 2025 |
| UP the Anti Ltd | Professional & scientific | 2021 |
| UP Your Grade Ltd | Education | 2018 |
| Upper 90 Tips Ltd | Arts & recreation | 2016 |
| Upskill Events Ltd | Arts & recreation | 2015 |
| Upson Downs Limited | Other services | 2008 |