| Trinity Motor Services Ltd | Other services | 2016 |
| Trinova Systems Limited | Information & communication | 1999 |
| Triple a Executive Ltd | Administrative & support | 2022 |
| Triple L Beauty and Training Ltd | Other services | 2025 |
| Triptex Group Limited | Administrative & support | 2026 |
| Triskelion Motorcycle Clothing / Accessories Limited | Wholesale & retail | 2012 |
| Triskelion Motorcycle Group Ltd | Wholesale & retail | 2017 |
| Triskelion Motorcycle Trading Ltd | Wholesale & retail | 2019 |
| Triskelion Motorcycle Training Ltd. | Education | 2009 |
| TRL Healthcare Innovation Ltd. | Health & social care | 2015 |
| Troman-Green Properties Limited | Real estate | 2005 |
| Troweling Monk CX Limited | Extraterritorial | 2015 |
| True to ZEN Ltd | Other services | 2022 |
| Truelogic Software Limited | Information & communication | 2025 |
| Truly Motors Ltd | Wholesale & retail | 2016 |
| Trust Investment Vehicle Limited | Real estate | 2021 |
| Trust Loyal Care Ltd | Health & social care | 2019 |
| Trusted Compliance & Governance Ltd | Information & communication | 2026 |
| TRY Again Arcade Ltd | Other services | 2025 |
| TS Autos Chesterfield Ltd | Wholesale & retail | 2024 |
| TSC Interiors Limited | Construction | 2016 |
| TSD Partners Limited | Other services | 2025 |
| TSF (Chesterfield) Ltd | Hospitality | 2023 |
| TSG Media Limited | Administrative & support | 1993 |
| TU Commerce Limited | Wholesale & retail | 2025 |
| Tubular Raise Scaffold Limited | Construction | 2014 |
| Tuff Riders Limited | Education | 2018 |
| Tunnicliffe Plant Solutions Ltd | Manufacturing | 2026 |
| Turk Takeaway Ltd | Hospitality | 2024 |
| Turkish Barber Hasland Ltd | Other services | 2024 |
| Turner Foster Property Ltd | Real estate | 2025 |
| Turner Investments Ltd. | Real estate | 1961 |
| Turner Machine Services Ltd | Manufacturing | 2021 |
| Turners Auto Services Limited | Wholesale & retail | 2014 |
| Turnforge Ltd | Professional & scientific | 2025 |
| Turnoaks Estates Ltd | Real estate | 2017 |
| Turnstone Developments (UK) Ltd | Real estate | 2013 |
| Turnstone Homes Limited | Construction | 2017 |
| Turton & Wade Holdings Ltd | Arts & recreation | 2026 |
| Tutu Dancewear Ltd | Wholesale & retail | 2012 |
| Tutum Medical Limited | Manufacturing | 2017 |
| TV Artist Limited | Arts & recreation | 2014 |
| TVR Transport Ltd | Transport & logistics | 2025 |
| TVW Ltd | Wholesale & retail | 2025 |
| TWC Recruitment Limited | Administrative & support | 2014 |
| Tweeze Beauty Studio Limited | Other services | 2019 |
| Twelve Property Ltd | Construction | 2016 |
| Twenty One Albion Road (Scarborough) Limited | Households | 2007 |
| TWH Residential Home Limited | Health & social care | 2012 |
| Twigg Holdings Limited | Real estate | 2018 |
| Twin Oaks Hotel Limited | Hospitality | 2010 |
| Twisted Spire Digital Media Ltd | Information & communication | 2020 |
| TWS Fabrication Ltd | Manufacturing | 2024 |
| TY Read Joinery Limited | Manufacturing | 2021 |
| Tybro Limited | Extraterritorial | 2014 |
| TYE Property Limited | Real estate | 2024 |
| Tyler Bros. (Sutton-In-Ashfield) Limited | Extraterritorial | 2014 |
| Tyler Brothers Limited | Extraterritorial | 2014 |
| Tyreguard Innovations Ltd | Wholesale & retail | 2025 |
| Tysons Transport Limited | Transport & logistics | 2025 |
| Tzuto Limited | Information & communication | 2017 |
| U Locked OUT Ltd | Administrative & support | 2025 |
| U Transition Limited | Professional & scientific | 2012 |
| UCB Ferrocast Limited | Extraterritorial | 2025 |
| UCB Starkey's Technicast Limited | Extraterritorial | 2025 |
| Ueia (Coal) Limited | Professional & scientific | 2013 |
| Ueia (Environmental) Limited | Professional & scientific | 2013 |
| Ueia (Water) Limited | Professional & scientific | 2013 |
| UGI Midlands Limited | Wholesale & retail | 2011 |
| UK Asbestos Training Association Limited | Other services | 2008 |
| UK Building Consultancy Ltd | Construction | 2024 |
| UK Camera Club Ltd | Wholesale & retail | 2018 |
| UK Construction Skills Ltd | Construction | 2016 |
| UK Eco Energy Solutions Ltd | Other services | 2017 |
| UK EGG Centre Limited | Wholesale & retail | 2007 |
| UK Electrical 999 Ltd | Construction | 2023 |
| UK Estimates Limited | Other services | 2018 |
| UK Painting Systems Limited | Construction | 2007 |
| UK Pizza & Kebab Limited | Hospitality | 2019 |
| UK Principal Designers Ltd | Professional & scientific | 2026 |
| UK PSO Solutions Ltd | Information & communication | 2011 |
| UK Search Limited | Administrative & support | 2004 |
| UK Select a Service Limited | Information & communication | 2023 |
| UK Tango Academy Limited | Wholesale & retail | 2023 |
| UK Trainers Limited | Wholesale & retail | 2024 |
| Ukata Limited | Education | 2014 |
| Ukbc (Midlands) Ltd | Construction | 2025 |
| ULH TEP Ltd | Manufacturing | 2018 |
| Ultimate Bathrooms Chesterfield Ltd | Wholesale & retail | 2026 |
| Ultimate Drive Club Ltd | Other services | 2026 |
| Ultimate Leadership Training Ltd | Professional & scientific | 2019 |
| Ultimate Mortgage Advice Limited | Other services | 2023 |
| Ultra Plumb Ltd | Construction | 2014 |
| Ultramarine Computing Limited | Information & communication | 1997 |
| Ultratan Limited | Other services | 2023 |
| Umbrella Facilities Management Limited | Administrative & support | 2017 |
| Unbreakable 90 Ltd | Education | 2023 |
| Uncle Japan (UK) Limited | Wholesale & retail | 2024 |
| Undo PMU Ltd | Health & social care | 2021 |
| Undo PMU Supplies Ltd | Wholesale & retail | 2024 |