| Twin Raven Software Limited | Financial services | 2020 |
| Twinkle Twinkle Red Star Limited | Hospitality | 2017 |
| Twlt Ltd | Transport & logistics | 2024 |
| Twltc Trading Limited | Arts & recreation | 2024 |
| Two Hours Sleep Limited | Information & communication | 2018 |
| Two Lime Hill Limited | Households | 2017 |
| Two Summers Productions Ltd | Information & communication | 2022 |
| Twpt Limited | Arts & recreation | 2020 |
| Twsg Limited | Arts & recreation | 1923 |
| Twsushi Ltd | Hospitality | 2026 |
| TX Five Group Ltd | Administrative & support | 2023 |
| Tycho Football Group Ltd | Hospitality | 2026 |
| Ubds Bidco Ltd | Financial services | 2024 |
| Ubds Crcc Limited | Financial services | 2024 |
| Ubds Group Holdings Ltd | Information & communication | 2021 |
| Ubds IT Consulting Limited | Information & communication | 2001 |
| UBQ Limited | Information & communication | 2010 |
| Udca Ltd | Financial services | 2024 |
| Udrigle Consultants Limited | Professional & scientific | 2020 |
| Udrigle Enterprises LLP | | 2020 |
| UF Couriers Limited | Transport & logistics | 2024 |
| UHF 62 Limited | Information & communication | 2017 |
| UK & International Health Coaching Association Limited | Administrative & support | 2018 |
| UK Distributor Ltd | Wholesale & retail | 2024 |
| UK Floorsave Online Limited | Wholesale & retail | 2019 |
| UK House Projects Ltd | Construction | 2021 |
| UK New Energy Ltd | Professional & scientific | 2021 |
| UK PPR Enterprises Ltd | Wholesale & retail | 2023 |
| UK the Online Beauty Courses Ltd | Education | 2024 |
| Ukgi Group Holdings Ltd | Financial services | 2024 |
| Ukgi Group Ltd | Professional & scientific | 2020 |
| Ukgi Limited | Financial services | 1998 |
| Ukgi Services Limited | Financial services | 2003 |
| Uksono Ltd | Health & social care | 2023 |
| Ulejra Limited | Information & communication | 2026 |
| Ultimate Athlete Sports Therapy Ltd | Wholesale & retail | 2010 |
| Ultralinx Ltd | Information & communication | 2014 |
| Ultralinx Networks Limited | Information & communication | 2014 |
| Umami IP Limited | Professional & scientific | 2016 |
| Umbrella MIX Limited | Information & communication | 2014 |
| Umme Bibi Limited | Real estate | 2021 |
| Uncomplicated Computing Ltd. | Professional & scientific | 2022 |
| Uncomplicated Group Ltd | Financial services | 2022 |
| Underwood Rise Management Company Limited | Households | 2006 |
| Underwoodsman Limited | Agriculture & fishing | 2006 |
| Unholy Guacamole Ltd | Hospitality | 2025 |
| Unicorn Advertising Limited | Administrative & support | 2006 |
| Unicorn Television Limited | Information & communication | 2002 |
| Unipar Services LLP | | 2015 |
| Unique Bids Limited | Administrative & support | 2019 |
| Unique Property Company London Ltd | Real estate | 2013 |
| Unit 29 Limited | Wholesale & retail | 2019 |
| Unit 94 Limited | Wholesale & retail | 2020 |
| Unit Group Collective Limited | Financial services | 2024 |
| Unit Group Developments Limited | Real estate | 2022 |
| United Associates (UK) Ltd | Administrative & support | 2007 |
| United Perfusion Services Limited | Health & social care | 2009 |
| United Stories by Arun Ltd | Information & communication | 2026 |
| Unity Music Ltd | Arts & recreation | 2021 |
| Universal Constructor Ltd | Information & communication | 2021 |
| Universal Property Consultants Limited | Real estate | 2005 |
| Unstopp/\Ble Limited | Professional & scientific | 2025 |
| UPC Investments Limited | Real estate | 2018 |
| Upcycled Beauty Ltd | Manufacturing | 2019 |
| Uplifting Events Limited | Arts & recreation | 2026 |
| Upper Grosvenor House Ltd | Other services | 2005 |
| Upper Pantiles Events Limited | Arts & recreation | 2022 |
| Uprise Outsourcing Ltd | Manufacturing | 2025 |
| Upton & Brinklow Ltd | Wholesale & retail | 2021 |
| UR Beauty Oasis Limited | Other services | 2025 |
| Urban and Village Ltd | Information & communication | 2010 |
| Urban Floors (Kent) Limited | Construction | 2026 |
| Urban Monkey Media Ltd | Information & communication | 2009 |
| Urban Property LAB Limited | Real estate | 2020 |
| Urban Scape Innovations Limited | Professional & scientific | 2025 |
| Urprops.Com Ltd | Real estate | 2021 |
| Useful Interiors Limited | Wholesale & retail | 2022 |
| Uuthree.Com Limited | Information & communication | 2009 |
| V & S (NO 12) Limited | Households | 1989 |
| V&P Capital Ltd | Financial services | 1999 |
| V&R Rawlings Ltd | Information & communication | 2018 |
| V&T Jewellery&Watch Repairs Limited | Other services | 2014 |
| V.F.M. Auto Sales Limited | Wholesale & retail | 2003 |
| V2R Partners Ltd | Manufacturing | 2026 |
| VAC Solar UK Ltd | Energy | 2017 |
| Vaida Psychology Ltd | Education | 2023 |
| Vale Health Clinic DEN Limited | Health & social care | 2025 |
| Vale Health Holdings Limited | Health & social care | 2023 |
| Vale Projects Limited | Real estate | 2001 |
| Vale Serve Ltd | Hospitality | 2026 |
| Vale Towers Freehold Limited | Households | 2014 |
| Valegrace LLP | | 2021 |
| Valiant Stories Limited | Manufacturing | 2021 |
| Valle Stud Ltd | Agriculture & fishing | 2020 |
| Valley BOY Limited | Information & communication | 2000 |
| Valléon Investments & Developments Ltd | Construction | 2025 |
| Value Partnership Ventures Limited | Professional & scientific | 2020 |
| Van DER Spuy Theatre Limited | Arts & recreation | 2012 |
| Vanchi Restaurant Ltd | Hospitality | 2025 |
| Vandemer Holdings Ltd | Financial services | 2020 |