| TWENTY7TEC Group Ltd | Information & communication | 2013 |
| TWENTY7TEC Topco Ltd | Financial services | 2024 |
| Twentyone International Ltd | Real estate | 2023 |
| Twickenham Technologies Limited | Professional & scientific | 1975 |
| Twikam Ltd | Information & communication | 2009 |
| Twin Firs Management (Bournemouth) Limited | Real estate | 1998 |
| Twin London Agency Limited | Professional & scientific | 2018 |
| Twin Oaks Turf Ltd. | Administrative & support | 2002 |
| Twin Peak Properties Limited | Construction | 2014 |
| Twin Pines Residents Association Limited | Households | 1996 |
| Twine Holdings Ltd | Financial services | 2023 |
| Twinnetic Solutions Ltd | Professional & scientific | 2020 |
| Twins Roslin Ltd | Households | 2021 |
| Twisb Devs Ltd | Information & communication | 2022 |
| Twist BOP POP Ltd | Wholesale & retail | 2021 |
| Twixt Chines Freehold Limited | Households | 2013 |
| Twkld Holdings Ltd | Financial services | 2022 |
| Two Four Eight Ltd | Information & communication | 2024 |
| Two&Four Ltd | Financial services | 2020 |
| Two-Way Mirror Limited | Professional & scientific | 2014 |
| Twostar Limited | Wholesale & retail | 2025 |
| TWP Property Holdings Limited | Construction | 2022 |
| Twyford House (Ferndown) RTM Company Limited | Households | 2013 |
| Twynham Investment Holdings Limited | Real estate | 2020 |
| Twynham Property Investments Limited | Real estate | 2020 |
| Twynham Training Limited | Education | 2009 |
| Tybmas Ltd | Other services | 2020 |
| Tyger Group Ltd | Health & social care | 2025 |
| Tylney Hall Limited | Real estate | 1986 |
| Tymon Trans Ltd | Transport & logistics | 2021 |
| Tynham Court Christchurch Ltd | Households | 2010 |
| Tyre Shack Limited | Wholesale & retail | 2015 |
| Tyres of Bournemouth Ltd | Wholesale & retail | 2023 |
| U PAY ( Southern ) Limited | Information & communication | 2026 |
| U-Drink Limited | Administrative & support | 2013 |
| U4L Limited | Professional & scientific | 2016 |
| U4LUK Renewables Ltd | Professional & scientific | 2018 |
| UB Components Ltd | Wholesale & retail | 2019 |
| Ucar Estate Ltd | Real estate | 2024 |
| Ucat Services Limited | Information & communication | 2017 |
| Uchenna Dance Limited | Arts & recreation | 2012 |
| UE Foods Ltd | Wholesale & retail | 2020 |
| Ugarte Engineering Services Limited | Information & communication | 2023 |
| UK - Sudan Partnership Limited | Administrative & support | 2019 |
| UK Aesthetic World Ltd | Other services | 2020 |
| UK Business Matters Limited | Administrative & support | 2007 |
| UK Church Directory Ltd | Information & communication | 2001 |
| UK Dentistry Ltd | Wholesale & retail | 2013 |
| UK Finance Corporation Limited | Real estate | 2005 |
| UK Global Business Services Ltd | Hospitality | 2021 |
| UK Health Link Limited | Health & social care | 2025 |
| UK International Machinery Limited | Administrative & support | 2009 |
| UK Laboratory Services Ltd | Manufacturing | 2014 |
| UK Letting Experts Ltd | Real estate | 2024 |
| UK Master Foods Ltd | Wholesale & retail | 2025 |
| UK Postage Stamps Ltd | Wholesale & retail | 2024 |
| UK PPE Supplies Ltd | Manufacturing | 2015 |
| UK Property Direct Ltd | Real estate | 2026 |
| UK Skills Forum Limited | Arts & recreation | 2017 |
| UK Souvenirs and Gift Limited | Wholesale & retail | 2015 |
| UK Total Lettings Ltd | Households | 2024 |
| UK Traction Limited | Transport & logistics | 2008 |
| UK Waste Busters Ltd | Water & waste | 2022 |
| UK Weekender Limited | Administrative & support | 2002 |
| UK Women’S Recovery Retreats Ltd | Other services | 2025 |
| Ukall Limited | Information & communication | 2017 |
| UKB Investments Ltd | Real estate | 2019 |
| UKB Marketing Ltd | Professional & scientific | 2017 |
| Ukey Investments Limited | Real estate | 2023 |
| Ukez Ltd | Hospitality | 2016 |
| Ukhc Limited | Financial services | 2025 |
| Ukhc Management Services Limited | Administrative & support | 2025 |
| Ukid Express Ltd | Transport & logistics | 2025 |
| UKO Limited | Wholesale & retail | 2005 |
| Ukssx Limited | Wholesale & retail | 2026 |
| Ukxp Ltd | Transport & logistics | 2025 |
| Ultimo Ventures Ltd | Arts & recreation | 2020 |
| Ultra Light Spinning Limited | Wholesale & retail | 2014 |
| UMA Construction Limited | Construction | 2009 |
| Umakara Ltd | Transport & logistics | 2024 |
| Umbrella Bathrooms Ltd | Construction | 2023 |
| Umbrella Improvements Ltd | Construction | 2020 |
| Umbuntubrit Ltd | Real estate | 2025 |
| UMC Group Limited | Extraterritorial | 2024 |
| Unboxed Group Experiential Limited | Professional & scientific | 2026 |
| Uncle Glenn’S Caribbean Food Ltd | Hospitality | 2022 |
| Uncles Holdings Ltd | Hospitality | 2022 |
| Undercover Rentals Ltd | Administrative & support | 2025 |
| Underwater Explorers Limited | Arts & recreation | 2005 |
| Underwater Visions Ltd | Other services | 2009 |
| UNI Way UK Ltd | Education | 2025 |
| Uniad Limited | Professional & scientific | 2021 |
| Unicorn Simulations Limited | Information & communication | 2019 |
| Union Home Solutions Ltd | Construction | 2025 |
| Uniqfilm Ltd | Information & communication | 2025 |
| Unique Barbers 17 Ltd | Other services | 2026 |
| Unique Bathrooms (Dorset) Limited | Wholesale & retail | 2011 |
| Unique Construction Southern Limited | Construction | 2017 |
| Unique Event Structures Ltd | Manufacturing | 2024 |
| Unique GAS Services Ltd | Energy | 2015 |