| Turtle Design Studio Ltd | Professional & scientific | 2023 |
| Tushmore Properties Ltd | Hospitality | 2025 |
| Tutoring at Home Ltd | Education | 2025 |
| Twenty Four Hours Ltd | Transport & logistics | 2022 |
| Twiga Properties Limited | Administrative & support | 2006 |
| Two Butterflies Limited | Administrative & support | 2017 |
| Two Guys Kitchens Limited | Wholesale & retail | 2003 |
| Two in One Design Limited | Extraterritorial | 2011 |
| Two Nine One Group Ltd | Financial services | 2023 |
| Twws Limited | Wholesale & retail | 2023 |
| Twyford Residential Properties Ltd | Hospitality | 2017 |
| Txrx Communications Ltd | Information & communication | 2007 |
| Tylers Consultancy Limited | Professional & scientific | 2013 |
| Tyrrell Consultants Ltd. | Information & communication | 1998 |
| U and V Sabharwal Enterprises Limited | Transport & logistics | 2015 |
| Udale Consultancy Limited | Professional & scientific | 2017 |
| UK Barrier Services Limited | Construction | 2002 |
| UK Cold Ltd | Construction | 2014 |
| UK Custom Aquascapes Ltd | Agriculture & fishing | 2025 |
| UK Greenmouse Limited | Wholesale & retail | 2022 |
| UK HGV Training Academy Ltd | Education | 2025 |
| UK Phone Pouches Ltd | Wholesale & retail | 2025 |
| UK Press Card Authority Ltd | Administrative & support | 2004 |
| UK Skin and Hair Care Ltd | Health & social care | 2016 |
| UK Zone Labs Ltd | Manufacturing | 2020 |
| UKN Limited | Information & communication | 2000 |
| UL Concord Holdings Limited | Financial services | 2022 |
| UL International (UK) Limited | Professional & scientific | 1996 |
| UL VS Limited | Professional & scientific | 1987 |
| Ultra Vans Limited | Wholesale & retail | 2021 |
| Ultracat Limited | Information & communication | 2017 |
| Ultraflex Induction UK Ltd | Wholesale & retail | 2025 |
| Ultramas Construction Ltd | Construction | 2026 |
| Umar Travels Limited | Transport & logistics | 2020 |
| Umlaut Consulting Ltd | Information & communication | 2013 |
| Umzingeli Properties Limited | Real estate | 2017 |
| Uncap Ltd | Professional & scientific | 2017 |
| Uncertain World Limited | Professional & scientific | 2006 |
| Undefeated Logistics Ltd | Transport & logistics | 2025 |
| Undeniable Value Limited | Information & communication | 2025 |
| Underdog Software Ltd | Information & communication | 2012 |
| Underdown Labs Limited | Information & communication | 2026 |
| Understanding HR Ltd | Administrative & support | 2025 |
| Uniqtc Ltd | Construction | 2019 |
| Unique Beauty S4:7 Limited | Other services | 2024 |
| Unique Romania Travel Limited | Administrative & support | 2016 |
| Unique Smile Group Limited | Health & social care | 2021 |
| United Distribution UK Ltd | Real estate | 2019 |
| United Kingdom Calisthenics Organisation Ltd | Education | 2023 |
| Unity Alignment Group Limited | Health & social care | 2020 |
| Unity Power Design Ltd | Professional & scientific | 2024 |
| Unity Support Services Ltd | Health & social care | 2021 |
| Universal Supreme Limited | Extraterritorial | 2011 |
| Universal Supreme Products Limited | Extraterritorial | 2011 |
| Unleashed Paddocks Limited | Agriculture & fishing | 2025 |
| Unlock Your Legend Limited | Administrative & support | 2025 |
| Unlocked Data Ltd | Information & communication | 2019 |
| Unresolved External Ltd | Information & communication | 2017 |
| UNS Consulting Services Limited | Information & communication | 2026 |
| Untapped in Tech Ltd | Administrative & support | 2026 |
| Upbeat Farming Enterprises LLP | | 2016 |
| Updraft Limited | Information & communication | 2012 |
| Upsellpos Ltd | Information & communication | 2025 |
| Upton Farm Enterprises Ltd | Agriculture & fishing | 2018 |
| Upton Farm Holdings Ltd | Professional & scientific | 2018 |
| UR Next Move Management Limited | Hospitality | 2018 |
| Urban Aristo Ltd | Wholesale & retail | 2024 |
| Urban Lensman Ltd | Information & communication | 2025 |
| Urban PM Properties Ltd | Real estate | 2021 |
| Urban Twist Ltd | Wholesale & retail | 2025 |
| Urbis Schreder Ltd | Manufacturing | 1973 |
| Urbitol Investments Ltd | Professional & scientific | 2011 |
| Urbrix Ltd | Real estate | 2024 |
| Urso JIU Jitsu Ltd | Education | 2025 |
| USA Nails (Basingstoke) Ltd | Other services | 2010 |
| Used Car Sites Limited | Professional & scientific | 2002 |
| Useful Dynamics Ltd | Information & communication | 2024 |
| User Centric Design Ltd | Professional & scientific | 2020 |
| Usudo Limited | Information & communication | 2024 |
| Uziza Realty Ltd | Real estate | 2025 |
| Uzzu Editor Ltd | Information & communication | 2025 |
| Uzzubiz Card Ltd | Information & communication | 2025 |
| Uzzumania Ltd | Information & communication | 2026 |
| Uzzuvoiceover Ltd | Information & communication | 2026 |
| V F Gasha Limited | Construction | 2026 |
| V V N V Ltd | Transport & logistics | 2016 |
| V&O Lettings Ltd | Real estate | 2022 |
| V2 Limited | Information & communication | 2000 |
| V20 Creative Ltd | Information & communication | 2023 |
| VA Events Limited | Hospitality | 2017 |
| Valence Drawing Services Ltd | Professional & scientific | 2008 |
| Valents Care Limited | Health & social care | 2015 |
| Valley Storage Limited | Real estate | 2021 |
| VALU8 Consulting Limited | Professional & scientific | 2019 |
| Value ADD Limited | Professional & scientific | 2003 |
| Valwer Limited | Administrative & support | 2024 |
| Van DER Pubs Limited | Hospitality | 2022 |
| Van-Addix Campers Ltd | Wholesale & retail | 2024 |
| Vantastic-Moves Ltd | Transport & logistics | 2004 |
| Vantastic-Waste Ltd | Water & waste | 2025 |