| TP IT Limited | Other services | 2023 |
| TP Reza Private Ltd. | Health & social care | 2014 |
| TPS Construction & Joinery Ltd | Construction | 2026 |
| Tracey Taylor Limited | Other services | 2023 |
| Tracklift Limited | Administrative & support | 2023 |
| Trade Timber Supplies Ltd | Wholesale & retail | 2017 |
| Tradeyhub Limited | Information & communication | 2025 |
| Tradia Software Ltd | Information & communication | 2019 |
| Tradie Inc Limited | Wholesale & retail | 2010 |
| Trafalgar Property Management Limited | Real estate | 2020 |
| Training for Transport Ltd | Administrative & support | 2016 |
| Trans-Caber Ltd | Transport & logistics | 2016 |
| TRANS4FIN Consulting Ltd | Professional & scientific | 2017 |
| Transama Ltd | Transport & logistics | 2017 |
| Transbeme Ltd | Professional & scientific | 2025 |
| Transformational HRM Limited | Administrative & support | 2020 |
| Transist Ltd | Administrative & support | 1997 |
| Transkol Ltd | Transport & logistics | 2014 |
| Travelblogg-Tours Ltd | Professional & scientific | 2025 |
| Travelportal.Io Ltd | Administrative & support | 2019 |
| Treadstone Properties Limited | Real estate | 2016 |
| Tree House OUT of School Club Community Interest Company | Administrative & support | 2011 |
| Tree Works UK (London) Limited | Administrative & support | 2011 |
| Trehaskaf Ltd | Wholesale & retail | 2021 |
| Trent Vehicle Remarketing Limited | Hospitality | 2012 |
| Trentside Tree Services Ltd | Agriculture & fishing | 2018 |
| Triangular Autos & Audio Limited | Wholesale & retail | 2006 |
| Tridentcards Mansfield Limited | Arts & recreation | 2016 |
| Trifle Digital Marketing Ltd | Professional & scientific | 2019 |
| Trimark Future Limited | Construction | 2015 |
| Trinite Homes Ltd | Health & social care | 2020 |
| Trinité Group Ltd | Health & social care | 2023 |
| Triumph Special Tuning Ltd | Wholesale & retail | 2016 |
| TRU Refractory Engineering Limited | Manufacturing | 2006 |
| True Position UK Limited | Wholesale & retail | 2012 |
| Truefix 24 Limited | Construction | 2025 |
| Truemed Group Ltd | Administrative & support | 2025 |
| Truly Scrumptious Delicatessen Limited | Hospitality | 2025 |
| Truly Scrumptious Ilkeston Limited | Hospitality | 2019 |
| Trust Building Supplies Limited | Real estate | 2015 |
| Trust Developments Notts Limited | Real estate | 2014 |
| Trust Property Solutions Limited | Real estate | 2006 |
| Truth Marketing and Advertising Ltd | Professional & scientific | 2007 |
| TSE IT Solutions Limited | Information & communication | 2024 |
| TSG Incorporated Limited | Wholesale & retail | 2014 |
| TSG Stock Trading Ltd | Financial services | 2021 |
| TSM Technical Ltd | Administrative & support | 2023 |
| TSP Business Ltd | Wholesale & retail | 2019 |
| TSP Limited | Manufacturing | 2018 |
| TSP Transport Ltd | Transport & logistics | 2014 |
| Tsppropertyrenovation Ltd | Construction | 2026 |
| TSR Ipswich Ltd | Administrative & support | 2018 |
| TSR Nottingham Ltd | Administrative & support | 2018 |
| TSZ Hubs Ltd | Administrative & support | 2018 |
| TTN Automations Limited | Manufacturing | 2025 |
| Tucker’S Tacos Ltd | Wholesale & retail | 2024 |
| Tudalou Ltd | Other services | 2022 |
| Tudor House Management Company Limited | Households | 1990 |
| Tudor Motoexperts Ltd | Wholesale & retail | 2025 |
| Tudor Tlcj Limited | Financial services | 2026 |
| Tudtrans Ltd | Transport & logistics | 2019 |
| TUI Security & Technology Ltd Ltd | Information & communication | 2026 |
| Tune Twelve Ltd | Real estate | 2025 |
| Turkish Barber Mansfield Limited | Other services | 2025 |
| Turkish Traditional Barber Ltd | Other services | 2025 |
| Turner's Residential Lettings Ltd | Real estate | 2023 |
| Turner-Wass Consulting Limited | Construction | 2003 |
| Turtle and Heron Media and Marketing Ltd | Information & communication | 2015 |
| Turtle Plant Ltd | Administrative & support | 2019 |
| Tuyo Circus Arts Limited | Arts & recreation | 2024 |
| TW IP Holdings Limited | Financial services | 2022 |
| TW Lightning Protection Ltd. | Construction | 2013 |
| Twenty Sports & Media Ltd | Other services | 2020 |
| Twenty Two Capital Group Limited | Financial services | 2025 |
| Twigg Family Investments Limited | Financial services | 2022 |
| Twigg Property Investments Limited | Administrative & support | 2021 |
| Twin Oaks Property Lettings Ltd | Real estate | 2021 |
| Two Hats Trading Limited | Wholesale & retail | 2021 |
| Two Oaks Consultancy Limited | Administrative & support | 2020 |
| Two Oaks Counselling Ltd | Health & social care | 2025 |
| Tyram Ltd | Transport & logistics | 2024 |
| Tyro Properties Ltd | Real estate | 2026 |
| Tytherleigh Holdings Limited | Real estate | 2023 |
| U & I Capital Ltd | Construction | 2025 |
| U Beauty Shire Limited | Other services | 2025 |
| U Just Cook Ltd | Information & communication | 2019 |
| U&S Associate Ltd | Professional & scientific | 2024 |
| U-Pile Limited | Construction | 2020 |
| U.C United Constructions Ltd | Construction | 2025 |
| U.K. Discovery Limited | Mining & quarrying | 1998 |
| Uberluxe International Limited | Extraterritorial | 1997 |
| Ucook Ltd | Construction | 2020 |
| UK Beauty Ltd | Information & communication | 2013 |
| UK Chicken and Kebab Ltd | Hospitality | 2020 |
| UK Glassroom Limited | Wholesale & retail | 2026 |
| UK Gritting Limited | Administrative & support | 2011 |
| UK Landis Limited | Professional & scientific | 2026 |
| UK OFF Licence 1 Ltd | Wholesale & retail | 2025 |
| UK OFF License Ltd | Wholesale & retail | 2026 |
| UK Prime Shop Ltd | Wholesale & retail | 2025 |