| Totum Group Ltd | Construction | 2022 |
| Touch Systems Holdings Limited | Professional & scientific | 2019 |
| Touchstone 3 Limited | Real estate | 2013 |
| Touchstone Trading Ltd | Wholesale & retail | 2022 |
| Touchwood Building Contractors Limited | Construction | 2007 |
| Touchwood Building Contracts Limited | Construction | 2010 |
| Touchwood Carpentry Ltd | Construction | 2022 |
| Touchwood Comms Limited | Information & communication | 2024 |
| Touchwood Group Ltd | Real estate | 2022 |
| Touchwood Motors Ltd | Wholesale & retail | 2019 |
| Touchwood Private Hire Limited | Transport & logistics | 2001 |
| Tough GUY Productions Limited | Information & communication | 2002 |
| Tourind Travel Ltd | Administrative & support | 2025 |
| Tovey's Helping Hands Ltd | Water & waste | 2022 |
| Tower Hill Trading Ltd | Real estate | 2012 |
| Tower House Oxford Limited | Hospitality | 2021 |
| Towermore Limited | Financial services | 2014 |
| Towers Digital Marketing Services Ltd | Professional & scientific | 2020 |
| Town and City PUB Group Limited | Hospitality | 2007 |
| Toyalertsuk Limited | Professional & scientific | 2023 |
| Toyosports (UK) Limited | Wholesale & retail | 2012 |
| Toyosports Ltd | Wholesale & retail | 2005 |
| TP Distribution Ltd | Extraterritorial | 1999 |
| TP Newlands Ltd | Real estate | 2025 |
| TP Star Limited | Real estate | 2022 |
| TPS (2015) Limited | Wholesale & retail | 2015 |
| TR Associates Structural Engineers Ltd | Construction | 2012 |
| TR Roofing Sheets Ltd | Wholesale & retail | 2020 |
| TR Training Solutions Ltd | Education | 2023 |
| Tracey Kirby Consulting LLP | | 2007 |
| Tracktize Ltd | Wholesale & retail | 2024 |
| Trade and Supplies Ltd | Wholesale & retail | 2025 |
| Trade BP Ltd | Extraterritorial | 2008 |
| Trade Bridge INT Limited | Information & communication | 2018 |
| Trade Conservatory Roofs Ltd | Manufacturing | 2023 |
| Trade Discount Shop Limited | Wholesale & retail | 2013 |
| Trade on Call Ltd | Administrative & support | 2025 |
| Trade Vehicle Security Limited | Administrative & support | 2021 |
| Trading Bullion Ltd | Wholesale & retail | 2022 |
| Trading Gems Ltd | Wholesale & retail | 2022 |
| Trading Luxury Ltd | Wholesale & retail | 2022 |
| Trading Red Ltd | Information & communication | 2024 |
| Trading Whiskey Limited | Wholesale & retail | 2025 |
| Trading Wines Limited | Wholesale & retail | 2025 |
| Traditional Healing Arts Ltd | Education | 2024 |
| Trafalgar Consultants Limited | Information & communication | 1994 |
| Trafalgar Court Residents Association (London) Limited | Households | 1994 |
| Train OUT Fitness Club Ltd | Arts & recreation | 2024 |
| Training Professionals Limited | Health & social care | 2013 |
| Training, Learning and Capacity Building Limited | Education | 2025 |
| Trampoline Events Limited | Arts & recreation | 2021 |
| Trans-Mena Development Limited | Professional & scientific | 2024 |
| Transferhub Limited | Transport & logistics | 2017 |
| Translate to Ltd | Professional & scientific | 2024 |
| Transmission Technology (UK) Ltd | Wholesale & retail | 2002 |
| Transmission Units and Co (Sales and Service) Limited | Wholesale & retail | 1985 |
| Transpeye Ltd | Administrative & support | 2016 |
| Tranters Events Ltd | Hospitality | 2025 |
| Travelluxx Limited | Transport & logistics | 2025 |
| Traya Co., Ltd. | Real estate | 2022 |
| Treacle and Swiss Limited | Arts & recreation | 2011 |
| Treadsoft Ltd | Information & communication | 2017 |
| Treadwell (Shirley) Management Company Limited | Households | 2022 |
| Tree Hill Legal Consultancy Limited | Professional & scientific | 2025 |
| Treescape Environmental Ltd | Administrative & support | 2017 |
| Treetops Group Limited | Real estate | 2021 |
| Tregaron Limited | Professional & scientific | 2014 |
| Trehern Investments Limited | Real estate | 2024 |
| Trend Hub Ltd | Wholesale & retail | 2022 |
| Trendy Essentials Ltd | Wholesale & retail | 2026 |
| Trendy Media Creation Ltd | Information & communication | 2022 |
| Trendy Texstyles Limited | Information & communication | 2016 |
| Trendy Trolley Limited | Wholesale & retail | 2025 |
| Trenita Ltd | Real estate | 2019 |
| Trent Taylor Ltd | Construction | 2020 |
| Trentham Logistics Limited | Extraterritorial | 2005 |
| Trevanna Properties Limited | Real estate | 2016 |
| Trevor Lawrence Limited | Health & social care | 2006 |
| TRI Wellness EWS Limited | Other services | 2026 |
| TRI Wellness Limited | Other services | 2019 |
| Tri-Ht Homes Ltd | Real estate | 2025 |
| Tria Pizza Ltd | Hospitality | 2026 |
| Triaim NGU Limited | Construction | 2020 |
| Trican Limited | Administrative & support | 1998 |
| Tricas Flooring Limited | Construction | 2017 |
| Tricas Flooring Solutions Limited | Construction | 2025 |
| Tricas Investments Limited | Real estate | 2022 |
| Trident Alternative Provision Ltd | Education | 2021 |
| Trident Property Enterprises Ltd | Real estate | 2023 |
| Tridente Medical Legal Ltd | Professional & scientific | 2025 |
| Trigo ADR UK Ltd | Professional & scientific | 2011 |
| Trigo Advanced Services Ltd | Professional & scientific | 2010 |
| Trigo Quality Management Limited | Professional & scientific | 2010 |
| Trilby Multimedia Limited | Information & communication | 2002 |
| Trilith Group Limited | Professional & scientific | 2015 |
| Trim Engineers & Modellers Ltd | Professional & scientific | 2025 |
| Trinam Limited | Real estate | 2015 |
| Trinculo Place Limited | Financial services | 2025 |
| Trine (Padstow) Limited | Construction | 1994 |
| Trine Developments Limited | Real estate | 2006 |