| Thoroughbreds in Sport Limited | Agriculture & fishing | 2023 |
| THP Consultancy Services Ltd | Professional & scientific | 2019 |
| Three Turns Shipping UK Ltd | Transport & logistics | 2022 |
| Throrrasy Ltd | Wholesale & retail | 2019 |
| Thundercat Technologies Limited | Administrative & support | 2006 |
| Thus Limited | Information & communication | 2009 |
| Thwang IT Comedian Limited | Arts & recreation | 2017 |
| Thyme Serviced Apartments Ltd | Hospitality | 2023 |
| Tiarco Limited | Professional & scientific | 1967 |
| Tidal Transit Holdings Limited | Professional & scientific | 2013 |
| Tide Communications Limited | Information & communication | 2001 |
| Tide Management Limited | Information & communication | 2001 |
| Tidgrove Estate Limited | Real estate | 2011 |
| Tidmarsh Court Limited | Households | 1971 |
| Tidu Mankoo Consulting Limited | Professional & scientific | 2016 |
| Tidworth Self Storage Limited | Wholesale & retail | 2014 |
| Tihan Decoration Ltd | Construction | 2026 |
| Tile Barn East Management Company Limited | Real estate | 2010 |
| Time Zone Accountancy Ltd | Professional & scientific | 2019 |
| Timede Limited | Information & communication | 2025 |
| Timeguard Limited | Extraterritorial | 2013 |
| Timeless Film Production Ltd | Information & communication | 2019 |
| Timothy Perris Building Contractors Limited | Construction | 2014 |
| Timpresents... Ltd | Arts & recreation | 2017 |
| Tina LE Consultant Ltd | Administrative & support | 2026 |
| Tippet (Basingstoke) Management Company Limited | Extraterritorial | 1983 |
| Tisha Consult Limited | Professional & scientific | 2012 |
| TJ Audiology Training Ltd | Education | 2023 |
| TJA Collective Ltd | Hospitality | 2025 |
| TJG Commercials Limited | Financial services | 2025 |
| TJR Consulting Ltd | Information & communication | 2002 |
| TK Business Consulting Limited | Professional & scientific | 2011 |
| TLC Property Services Ltd | Construction | 2010 |
| TLS Electrical Solutions Ltd | Manufacturing | 2026 |
| TMD Private Ltd | Transport & logistics | 2023 |
| TMI Mechanical Limited | Construction | 2015 |
| TMR Asset Management Ltd | Professional & scientific | 2025 |
| Tnsg Health Co., Ltd. | Extraterritorial | 2012 |
| Toby Burnham Communications Limited | Administrative & support | 2013 |
| TOM Automatic Driving School Limited | Education | 2020 |
| TOM Greenly Limited | Financial services | 2017 |
| TOM MAY Limited | Health & social care | 2022 |
| Tomas Stosak Limited | Transport & logistics | 2014 |
| Toneband Limited | Professional & scientific | 2013 |
| Tony Pryce Retail Limited | Extraterritorial | 2003 |
| Top Notch Carpentry Ltd | Construction | 2017 |
| Top PR Limited | Professional & scientific | 2010 |
| Topcon (Great Britain) Medical Limited | Wholesale & retail | 1980 |
| Torch Plumbing and Heating Ltd | Construction | 2017 |
| Tori Bryant Contracts Ltd | Professional & scientific | 2014 |
| Torpen Capital Limited | Financial services | 2025 |
| Total Climate Ltd | Manufacturing | 2020 |
| Total Door Services Limited | Construction | 2014 |
| Total Glass Services Limited | Wholesale & retail | 2023 |
| Total Life Health Ltd | Health & social care | 2025 |
| Totem Property Services Limited | Administrative & support | 2018 |
| Toty Electronics Ltd | Manufacturing | 2024 |
| Touch Blue Limited | Administrative & support | 2005 |
| Touch of Angels TOA Ltd | Hospitality | 2016 |
| Tourmalet Holdings Ltd | Real estate | 2020 |
| Town Mills Flats Limited | Administrative & support | 1981 |
| TR Globalevents Ltd | Hospitality | 2014 |
| Tracy James Hearing Ltd | Wholesale & retail | 2023 |
| Trailblazing Films Ltd | Information & communication | 2019 |
| Training for Transportation Professionals Limited | Professional & scientific | 2009 |
| Tranquil Film Production Ltd | Information & communication | 2019 |
| Travel Master (MCR) Limited | Transport & logistics | 2004 |
| Travelabout Limited | Administrative & support | 2001 |
| Travelrest Limited | Hospitality | 2000 |
| Travelsauce Limited | Administrative & support | 2025 |
| Travis International Drilling Limited | Mining & quarrying | 2013 |
| TRC Construction Services Ltd | Professional & scientific | 2020 |
| Treelity Ltd | Information & communication | 2018 |
| Treerecycle Ltd | Manufacturing | 2023 |
| Treevolution Ltd | Agriculture & fishing | 2024 |
| Trellisworks Holdings Limited | Financial services | 2022 |
| Trellisworks Limited | Information & communication | 2004 |
| Trenchard Coaching Ltd | Arts & recreation | 2023 |
| Treo Bespoke Ltd | Construction | 2023 |
| Treo MGD Construction Limited | Construction | 2018 |
| Triage Pharma Limited | Professional & scientific | 2012 |
| Tricom Ltd | Professional & scientific | 2008 |
| Trigon Construct Ltd | Construction | 2026 |
| Trigon Ltd | Professional & scientific | 2019 |
| Trimed Limited | Wholesale & retail | 2020 |
| Trinity Court Freehold Limited | Households | 2022 |
| Trinity Court Property Limited | Real estate | 2005 |
| Trinity House Holdings Ltd | Financial services | 2017 |
| Triple'L' Consultancy Ltd | Professional & scientific | 2018 |
| Triumph Transport Ltd | Transport & logistics | 2019 |
| TRM Technologies Ltd | Other services | 2021 |
| Trmc Ltd | Administrative & support | 2017 |
| Trooserpxe Limited | Wholesale & retail | 2024 |
| Trottr Ltd | Information & communication | 2026 |
| Trove Limited | Wholesale & retail | 2004 |
| Truce Entertainment Limited | Information & communication | 2016 |
| Trucker PL Ltd | Transport & logistics | 2015 |
| True Fit Physiotherapy Limited | Extraterritorial | 2016 |
| TRUE2YOU Wedding Boutique Limited | Wholesale & retail | 2024 |
| Truesync IOT Systems Global Ltd | Manufacturing | 2020 |