| Trotfield Windows Limited | Other services | 2012 |
| TRS (Personnel) Ltd | Administrative & support | 2005 |
| Trucker's Missus Ltd | Wholesale & retail | 2025 |
| Trucklings Ltd | Wholesale & retail | 2025 |
| True Bites Limited | Wholesale & retail | 2009 |
| True Care Solutions Limited | Health & social care | 2016 |
| True Care Staffing UK Ltd | Administrative & support | 2025 |
| True Care Support Services Ltd | Administrative & support | 2023 |
| Trueheat Limited | Construction | 2024 |
| Truelycare Limited | Health & social care | 2020 |
| Trugal Ltd | Other services | 2019 |
| Trumata Ltd | Wholesale & retail | 2019 |
| Trust BI Limited | Information & communication | 2011 |
| Trustmark Services (Mechanical) Limited | Construction | 2020 |
| Trustmark Services (Renewable) Limited | Construction | 2020 |
| Trustmark Services Limited | Construction | 2020 |
| Trustwoodbars Ltd | Construction | 2024 |
| Trutow Appraisals Limited | Transport & logistics | 2025 |
| TSB Returns Limited | Transport & logistics | 2014 |
| Tsoi Optics Limited | Health & social care | 2024 |
| TSP Media Group Ltd | Professional & scientific | 2008 |
| TSP Media Limited | Information & communication | 2024 |
| TSR Events Ltd | Arts & recreation | 2017 |
| TSRE21 Limited | Arts & recreation | 2021 |
| TSS Midlands Ltd | Administrative & support | 2026 |
| TST Safety Ltd | Professional & scientific | 2020 |
| TT54 Limited | Real estate | 2019 |
| TTC 2000 Limited | Education | 2013 |
| TTC Commercial Services Limited | Administrative & support | 2003 |
| Ttcm Limited | Health & social care | 2010 |
| TTD Transformational Training and Development Ltd | Education | 2017 |
| Ttfc Ltd | Arts & recreation | 2023 |
| TTM Consultancy Limited | Information & communication | 2007 |
| TTS Global Ltd | Transport & logistics | 2015 |
| Tudocris Property Management Ltd | Real estate | 2024 |
| Tuhada Food Limited | Hospitality | 2024 |
| Tulip Recreation Limited | Arts & recreation | 2024 |
| Tunwell Trade Limited | Wholesale & retail | 2022 |
| Turas Accountants Limited | Professional & scientific | 2012 |
| Turbos and Ecus Limited | Wholesale & retail | 2021 |
| Turkish Barberz Ltd | Other services | 2024 |
| Turkish F4DE Ltd | Other services | 2025 |
| Turner Systems Limited | Information & communication | 2017 |
| Turners Plumbing & Heating (Shropshire) Ltd | Construction | 2021 |
| Tutti Avanti Ltd | Professional & scientific | 2025 |
| TV Furniture Direct Limited | Wholesale & retail | 2015 |
| Twelve Islands Ltd | Wholesale & retail | 2025 |
| TWELVE45 Limited | Information & communication | 2024 |
| TWG-P3M Ltd | Professional & scientific | 2022 |
| Twiggy's Day Nursery Limited | Health & social care | 2016 |
| Twilight Sleep Support Limited | Education | 2021 |
| Twin Peaks Bidco Limited | Financial services | 2020 |
| Twin Peaks Topco Limited | Financial services | 2020 |
| Twisaq Ltd | Other services | 2019 |
| Twist N Shakes Ltd | Wholesale & retail | 2025 |
| Two Tipsy Turtles Limited | Hospitality | 2022 |
| Twrj Ltd | Professional & scientific | 2025 |
| Tyler Raymond Limited | Wholesale & retail | 2025 |
| Type Solution Ltd | Other services | 2018 |
| Tyrell Models Limited | Wholesale & retail | 2023 |
| Tyres Pro Fit Limited | Wholesale & retail | 2025 |
| TYS Pressure Washing Services Domestic & Commercial Ltd | Administrative & support | 2022 |
| U2Z Clinical Solutions Ltd | Health & social care | 2023 |
| Ubuntu Group Ltd | Administrative & support | 2021 |
| Udderly Limited | Manufacturing | 2024 |
| Ufeas Ltd | Other services | 2019 |
| Ugochez Limited | Health & social care | 2020 |
| Ujica Ltd | Transport & logistics | 2010 |
| UK Auto Pro Limited | Wholesale & retail | 2020 |
| UK Auto Wrapping Limited | Extraterritorial | 2023 |
| UK Autocolours Ltd | Wholesale & retail | 2025 |
| UK Ceilings Limited | Construction | 2012 |
| UK Constructive Solutions Ltd | Construction | 2024 |
| UK Diamond Centre Ltd | Wholesale & retail | 2011 |
| UK Ecig Vendor Limited | Wholesale & retail | 2015 |
| UK Electric Gate Company Limited | Administrative & support | 2012 |
| UK Holland Motors Ltd | Wholesale & retail | 2025 |
| UK ICT Ltd. | Information & communication | 2006 |
| UK Inflatables Ltd | Manufacturing | 2024 |
| UK Land Referencing Services Limited | Professional & scientific | 2015 |
| UK Laser Cleaning Limited | Administrative & support | 2023 |
| UK LED Lights Ltd | Wholesale & retail | 2019 |
| UK Premix Limited | Extraterritorial | 2006 |
| UK Roofing & Scaffolding Specialists Ltd | Construction | 2020 |
| UK Scaffolding & Roofing Specialists Ltd | Construction | 2024 |
| UK Soft Play Ltd | Manufacturing | 2026 |
| UK Sports Training Ltd | Administrative & support | 2012 |
| UK Springs Ltd | Wholesale & retail | 2026 |
| UK Tinting Solutions Ltd | Wholesale & retail | 2011 |
| UK to Europe Courier Ltd | Transport & logistics | 2026 |
| UK Waste Solutions Limited | Water & waste | 2003 |
| Ukinet Media Ltd | Information & communication | 2003 |
| UKK Logistics Ltd | Transport & logistics | 2022 |
| Ulim Ltd | Other services | 2019 |
| Ultimate Meets Ltd | Other services | 2023 |
| Ultimate Sparkle Ltd | Administrative & support | 2025 |
| Ultimate Vehicle Services Limited | Wholesale & retail | 2024 |
| Ultra Avionics Limited | Manufacturing | 2009 |
| Ultra Clean Window Cleaning Specialists Limited | Administrative & support | 2017 |
| Ultra Computers Ltd | Manufacturing | 2017 |