| THE Tapas World Ltd | Hospitality | 2025 |
| THE TCS Foundation CIC | Education | 2025 |
| THE TEN Musical Ltd | Information & communication | 2020 |
| THE Threador Ltd | Wholesale & retail | 2025 |
| THE UK Foundation of the University of British Columbia | Education | 2004 |
| THE VA Nest Ltd | Extraterritorial | 2022 |
| THE Villard Effect Ltd | Professional & scientific | 2022 |
| THE Walks Huntingdon (NO.3) Management Company Limited | Real estate | 2007 |
| THE Warwick Close Management Company Limited | Households | 2009 |
| THE Way Jewellery Ltd | Manufacturing | 2025 |
| THE Weybridge Park Residents Association Limited | Households | 1977 |
| Theatre Temoin Limited | Arts & recreation | 2011 |
| Thebigone Limited | Manufacturing | 2025 |
| Theomar Ltd | Manufacturing | 2015 |
| Thepivotalspace Ltd | Professional & scientific | 2021 |
| Theyieldseeker Ltd | Real estate | 2016 |
| Third Chillerton Residents Association (Hampton) Limited | Households | 1981 |
| Thomas Doyle Ltd | Construction | 2016 |
| Thompson Paving UK Limited | Administrative & support | 2013 |
| Three Ltd | Information & communication | 1998 |
| Thurston Group 2025 Ltd | Financial services | 2025 |
| TIA Choy Industries Limited | Real estate | 2014 |
| Tier 1 London Ltd | Professional & scientific | 2015 |
| Tierney Electrical Contractors Limited | Construction | 2014 |
| TIM Barfield Marine Limited | Manufacturing | 2024 |
| TIM Syrad Limited | Wholesale & retail | 2006 |
| TIM Syrad Wine Tours Ltd | Wholesale & retail | 2015 |
| Times Outsourcing Ltd | Administrative & support | 2026 |
| Tiny Vessel Brewing Company Limited | Manufacturing | 2006 |
| Tipsy LA LA Limited | Other services | 2011 |
| TJS Transport Limited | Transport & logistics | 1998 |
| TK & M Properties Ltd | Extraterritorial | 2017 |
| Tm's Mobile Styles Limited | Other services | 2005 |
| TMS Electrical Solution Limited | Construction | 2022 |
| Todo Furniture Ltd | Manufacturing | 2018 |
| Tokaj Merchants Ltd | Wholesale & retail | 2012 |
| Tongue Taste Limited | Wholesale & retail | 2026 |
| Tony Chentrens Design and Build LLP | | 2013 |
| Toonz Entertainment UK Limited | Extraterritorial | 2012 |
| Toot (Technologies) Ltd | Information & communication | 2018 |
| Top Deck Cruises Ltd | Arts & recreation | 2024 |
| Topaz Consulting Limited | Information & communication | 2025 |
| Touchlight DNA Services Limited | Professional & scientific | 2015 |
| Touchlight Genetics Limited | Professional & scientific | 2007 |
| Touchlight Holdings Limited | Financial services | 2014 |
| Touchlight IP Limited | Administrative & support | 2014 |
| Touchlight Limited | Extraterritorial | 2016 |
| Touchlines Limited | Information & communication | 2005 |
| Touchstack Ltd | Information & communication | 2025 |
| Tower of Power Limited | Real estate | 1995 |
| TR Domestic Services Limited | Administrative & support | 2012 |
| Trade and Tested Ltd | Information & communication | 2007 |
| Tranquillo Limited | Information & communication | 2022 |
| Trans World Media Limited | Professional & scientific | 1969 |
| Transmove Express Limited | Transport & logistics | 2025 |
| Transworld Media Services Limited | Professional & scientific | 2026 |
| Traveltradeevents Ltd | Administrative & support | 2020 |
| Tretyakov Technology Ltd | Information & communication | 2026 |
| Tri-Nations Migration Limited | Professional & scientific | 2020 |
| Trikoty Ltd | Wholesale & retail | 2019 |
| Trini Connection UK Limited | Wholesale & retail | 2008 |
| Trio Global Investments Ltd | Real estate | 2019 |
| Triple GEM Holdings Limited | Real estate | 2015 |
| Tristar Property Ltd | Real estate | 2019 |
| Trust in Coaching Ltd | Professional & scientific | 2025 |
| Trustworthy Properties Ltd | Real estate | 2019 |
| Ts&E Build Ltd | Construction | 2015 |
| Tsang Properties Ltd | Real estate | 2016 |
| TSQ Investments Limited | Professional & scientific | 2007 |
| TT Corporation Limited | Professional & scientific | 2015 |
| TTP Financial Compensation Limited | Other services | 2012 |
| Tunbridge Assets Ltd | Real estate | 2016 |
| Turkington Design Studio Limited | Professional & scientific | 2012 |
| Turkington Martin Trustees Limited | Administrative & support | 2020 |
| Turn House Ltd | Real estate | 2026 |
| Tvcis Ltd | Manufacturing | 2024 |
| Twelve Noon Limited | Administrative & support | 2005 |
| Twickenham Investments Limited | Real estate | 2024 |
| Twickenham Preparatory School | Education | 1997 |
| Twinkle Toes Dancing Ltd | Arts & recreation | 2011 |
| Twinteam Trans Ltd | Transport & logistics | 2022 |
| Twinwood Properties Ltd | Real estate | 2016 |
| TY Gwyn Design & Consulting Ltd | Professional & scientific | 2025 |
| Tyche UK Office Ltd | Wholesale & retail | 2022 |
| Tykhe Enterprises Limited | Real estate | 2017 |
| Tylos Logistics Limited | Wholesale & retail | 2012 |
| Ubnb Properties Limited | Households | 2023 |
| UIG Limited | Wholesale & retail | 2013 |
| UK China Technology and Innovation Alliance Limited | Professional & scientific | 2025 |
| UK CRE Services Ltd | Real estate | 2023 |
| UK ENC Ltd | Wholesale & retail | 2012 |
| UK Floating Homes Ltd | Real estate | 2012 |
| Ukmh Consulting Ltd | Professional & scientific | 2021 |
| Unarchive Limited | Information & communication | 2025 |
| Unic Personnel Ltd. | Health & social care | 2014 |
| Unicorn Global Partners Limited | Financial services | 2017 |
| Unicorn Land Limited | Real estate | 2019 |
| Unified Reality Ltd | Wholesale & retail | 2021 |
| Unifysim Ltd | Information & communication | 2025 |
| Unireal Ltd | Real estate | 2017 |