| Turners Hill Estate Limited | Real estate | 2019 |
| Turners Microsystem Ltd | Information & communication | 2005 |
| Turnpike Vapes Limited | Wholesale & retail | 2016 |
| Tuskerbay Ltd | Wholesale & retail | 2025 |
| Tust Consultancy Ltd | Professional & scientific | 2018 |
| TUW Limited | Public administration | 2025 |
| Tvarita Partners Ltd | Information & communication | 2025 |
| TVC 15 Limited | Extraterritorial | 2010 |
| TVC 16 Limited | Extraterritorial | 2010 |
| TVC Optical Ltd | Wholesale & retail | 2020 |
| Tvisha Enterprise Limited | Hospitality | 2018 |
| TVP Fire Ltd | Construction | 2022 |
| TW Carriages Ltd | Transport & logistics | 2016 |
| TW Pathology Limited | Health & social care | 2023 |
| TW23 Ltd | Real estate | 2023 |
| TW30 Limited | Information & communication | 2010 |
| Tweakments Guide Limited | Information & communication | 2018 |
| Twelve Horizon Ltd | Health & social care | 2025 |
| Twelve Telecom Limited | Information & communication | 2011 |
| Twelvers Connect Ltd | Wholesale & retail | 2014 |
| Twelvers Link Ltd | Wholesale & retail | 2011 |
| Twenty 20 Development Ltd | Construction | 2019 |
| Twenty Events Limited | Arts & recreation | 2020 |
| Twenty One Eight Limited | Health & social care | 2017 |
| Twentysix Black Ltd | Information & communication | 2024 |
| Twickenham Rugby Hospitality Ltd | Hospitality | 2023 |
| Twiga Health Limited | Information & communication | 2016 |
| Twiga Real Estate Ltd | Real estate | 2024 |
| Twiglets Developments Limited | Construction | 2016 |
| Twilight Consultancy Limited | Professional & scientific | 2013 |
| Twin Meadow Investments Ltd | Real estate | 2016 |
| Twin Pharma Ltd | Wholesale & retail | 2024 |
| Twinkle Enterprises Limited | Information & communication | 2025 |
| Twinkle Group Ltd | Wholesale & retail | 2022 |
| Twinklestar Fashion Accessories Ltd | Manufacturing | 2012 |
| Twinnies Minis Ltd | Education | 2024 |
| Twinpalm Ltd | Financial services | 2022 |
| Twins Construction Limited | Construction | 2003 |
| Twins Sailing Ltd | Transport & logistics | 2025 |
| Twisha Infotech UK Limited | Information & communication | 2023 |
| Twist Ice-Cream Ltd | Hospitality | 2011 |
| Twisture FAB Ltd | Wholesale & retail | 2025 |
| Two Factor Theory Ltd. | Information & communication | 2014 |
| Two Oaktree Ltd | Real estate | 2015 |
| Two Top Hats Limited | Other services | 2014 |
| Two Trees Capital Ltd | Financial services | 2022 |
| Two Two Zero Blythe Road Management Limited | Households | 2012 |
| Two Wander Ltd | Wholesale & retail | 2022 |
| Two Waters Limited | Health & social care | 2022 |
| Two Weeks International Volunteer Network | Administrative & support | 2008 |
| Twobabies Limited | Arts & recreation | 2009 |
| Twomindss Ltd | Wholesale & retail | 2026 |
| TX Ready Ltd | Information & communication | 2026 |
| TX1 Labs Ltd | Information & communication | 2022 |
| TY Logan Limited | Information & communication | 2021 |
| Tyche Investment Group Limited | Real estate | 2019 |
| Tycoon Sales Ltd | Wholesale & retail | 2025 |
| Tyler Management Limited | Construction | 2025 |
| Type IT Limited | Administrative & support | 2021 |
| Typesfair Limited | Wholesale & retail | 2025 |
| Tyrant Ltd | Information & communication | 2014 |
| Tyrrell Engineering Limited | Manufacturing | 2020 |
| Tyson Spaces Ltd | Real estate | 2025 |
| Tzarevetz Ltd | Wholesale & retail | 2020 |
| U & a Consultants Limited | Other services | 2017 |
| U & I London Ltd | Wholesale & retail | 2021 |
| U & U Ltd | Wholesale & retail | 1999 |
| U N H Sirisena Limited | Real estate | 2012 |
| U R Realestate Limited | Real estate | 2010 |
| U.K School of English Ltd | Education | 2002 |
| Uabo Ltd | Professional & scientific | 2019 |
| Uavictor Aerospace Ltd | Manufacturing | 2017 |
| Uballyhoo Ltd | Professional & scientific | 2023 |
| Ubatori Ltd | Information & communication | 2024 |
| Ubayyat Limited | Construction | 2025 |
| Uber Property Services Ltd | Construction | 2015 |
| Uber Rental Limited | Construction | 2014 |
| Uberdoc Ltd | Administrative & support | 2017 |
| Ubhans Properties Ltd | Real estate | 2020 |
| UBP Catering Ltd | Hospitality | 2012 |
| UC Print Limited | Administrative & support | 2008 |
| UC Residential Ltd | Real estate | 2025 |
| Uche & Co Ltd | Health & social care | 2022 |
| Ucns Limited | Information & communication | 2007 |
| UD Investments Limited | Real estate | 2017 |
| UD Media Limited | Information & communication | 2025 |
| Udathu Holdings Ltd | Real estate | 2021 |
| Udayveer Ltd | Real estate | 2020 |
| Udental Ltd | Health & social care | 2024 |
| UDF Xpress UK Ltd | Transport & logistics | 2012 |
| Udyog Mandir PVT Ltd | Information & communication | 2013 |
| Ugam Supply Ltd | Water & waste | 2025 |
| UGAM9 Limited | Information & communication | 2020 |
| UGE Creations Ltd | Construction | 2015 |
| Ugly UK Limited | Construction | 2022 |
| UGO Sparkk Ltd | Construction | 2025 |
| Ugofx Trading Ltd | Administrative & support | 2022 |
| Ugorjious Limited | Health & social care | 2016 |
| UHG Properties Limited | Health & social care | 2024 |
| Uicaiinc Ltd | Wholesale & retail | 2021 |