| Truecommerce (Oldham) Limited | Information & communication | 1992 |
| Truecommerce Holdings Limited | Information & communication | 2014 |
| Truecommerce UK (Holdings) Limited | Professional & scientific | 2007 |
| Truedoxa Educational Project CIC | Education | 2025 |
| Truedoxa Global Resources Ltd | Education | 2025 |
| Trueline Distribution Ltd | Wholesale & retail | 2025 |
| Trunex Limited | Manufacturing | 2025 |
| Trust Ledger Accounting Limited | Professional & scientific | 2025 |
| Trustcutz Ltd | Other services | 2023 |
| Trustwell Healthcare Services Ltd | Health & social care | 2020 |
| Trutxt Ltd | Information & communication | 2025 |
| Truworth Investments Ltd | Wholesale & retail | 2021 |
| Trynatty Ltd | Manufacturing | 2025 |
| Tshua Ltd | Real estate | 2022 |
| Tshua Maintenance Ltd | Construction | 2026 |
| TSM Ventures Limited | Public administration | 2025 |
| TSR Safety Ltd | Manufacturing | 2019 |
| TSY Services Ltd | Professional & scientific | 2017 |
| TT Sports Therapy Limited | Arts & recreation | 2023 |
| TTB Pluto Limited | Financial services | 2026 |
| Ttba M Limited | Real estate | 2019 |
| Tthc Limited | Administrative & support | 2004 |
| TTS Trading Limited | Arts & recreation | 2021 |
| Tttv Holdings Ltd | Real estate | 2026 |
| Tuckingmill Manco Limited | Households | 2023 |
| Tugabroadcast Ltd | Information & communication | 2022 |
| Tukwan Limited | Administrative & support | 2026 |
| Tulip Day Care Ltd | Health & social care | 2018 |
| Tully Consulting Limited | Professional & scientific | 2022 |
| Tune Smart Ltd | Information & communication | 2025 |
| Tuned in Ltd | Health & social care | 2023 |
| Tuntunre Ltd | Wholesale & retail | 2026 |
| Turenora Ltd | Wholesale & retail | 2026 |
| Turing Bioscience Limited | Professional & scientific | 2026 |
| Turjuman Languages Ltd | Professional & scientific | 2018 |
| Turmo Limited | Wholesale & retail | 2024 |
| Turnertrain Limited | Professional & scientific | 2025 |
| Turquoise Real Estate Limited | Real estate | 2025 |
| Tuxteam Ltd | Administrative & support | 2020 |
| TV Warehouse Limited | Information & communication | 2004 |
| TVS Group Ltd | Real estate | 2024 |
| TW Automations Ltd | Information & communication | 2026 |
| TW Insolvency Ltd | Financial services | 2021 |
| Twanny Luxe Limited | Administrative & support | 2024 |
| Tweenleaf Ltd | Wholesale & retail | 2025 |
| Twenty Oaks, Ltd | Manufacturing | 2017 |
| Twenty Twenty (MCR) Ltd | Wholesale & retail | 2020 |
| Twentyfoursix Limited | Administrative & support | 2016 |
| Twersky & Hager Group Ltd | Real estate | 2020 |
| Tweyelight Digital Ltd | Administrative & support | 2025 |
| Twinkle Tots Daycare Ltd | Health & social care | 2025 |
| Twisted Entertainment Limited | Other services | 2018 |
| Twisted Runway Ltd | Hospitality | 2021 |
| TYH Flooring Supplies Ltd | Construction | 2025 |
| TYH247 Ltd | Administrative & support | 2024 |
| Tyhfashion Limited | Wholesale & retail | 2025 |
| Tyldesley Recovery Limited | Transport & logistics | 2006 |
| Tyler Wilson Estates Ltd | Real estate | 2021 |
| Tyne Estates Ltd | Other services | 2017 |
| Tyres Manchester Ltd. | Wholesale & retail | 2014 |
| Tyrone O’Shea Ltd | Extraterritorial | 2020 |
| Tyson Roofing Ltd | Construction | 2012 |
| TYY Cheder Ltd | Education | 2022 |
| TYY Childcare Ltd | Health & social care | 2022 |
| TYY Investments Ltd | Real estate | 2023 |
| TZD Ltd | Wholesale & retail | 2025 |
| Tzedek ADR Services Ltd | Professional & scientific | 2015 |
| Tzvia Ltd | Professional & scientific | 2025 |
| TÍR AYÉ Ltd | Financial services | 2025 |
| U & S Investment Ltd | Construction | 2018 |
| U Mart Super Market Ltd | Wholesale & retail | 2017 |
| U&R Properties Ltd | Administrative & support | 2020 |
| U.K. Construction Media Limited | Information & communication | 2014 |
| U.K. Import Corporation Limited | Wholesale & retail | 1995 |
| U2 Global Limited | Information & communication | 2018 |
| UA Performance Ltd | Professional & scientific | 2025 |
| Ubiquity Media Ltd | Other services | 2018 |
| Ubrant Ltd | Information & communication | 2024 |
| Ubrave Ltd | Extraterritorial | 2012 |
| UBUNTU365 Healthcare Services Ltd | Health & social care | 2022 |
| Ucheoma Ltd | Real estate | 2023 |
| Udou Creatives Ltd | Other services | 2023 |
| UDP Group Limited | Financial services | 2016 |
| UFA Distro Ltd | Wholesale & retail | 2024 |
| UI Estates Ltd | Real estate | 2025 |
| UK & China Gourmet Cultural Communication Association | Professional & scientific | 2017 |
| UK Arch Construction Limited | Construction | 2015 |
| UK Business Events Limited | Administrative & support | 2017 |
| UK China United Football Development Co. Ltd | Other services | 2015 |
| UK Eagle Supply Limited | Financial services | 2025 |
| UK Education Consultants Limited | Education | 2014 |
| UK Electrical Wholesalers Limited | Wholesale & retail | 2013 |
| UK Exchange Limited | Financial services | 2011 |
| UK Floor Coatings Ltd | Construction | 2020 |
| UK Food Hub Ltd | Hospitality | 2024 |
| UK Frontier Ltd | Administrative & support | 2018 |
| UK Genmin Investments Limited | Financial services | 2024 |
| UK Gentle Barber Ltd | Other services | 2020 |
| UK Heathcote Bidco Ltd. | Other services | 2018 |
| UK Heathcote Holding Ltd. | Other services | 2018 |