| Transglobe Commerce LP | | 2017 |
| Transito Limited | Transport & logistics | 2024 |
| Translink Express Logistics Ltd | Transport & logistics | 1987 |
| Transltr Ltd | Information & communication | 2006 |
| Transmon Engineering Limited | Manufacturing | 2001 |
| Transoceans Logistics Ltd | Professional & scientific | 2023 |
| Transparent Energy Solutions Limited | Professional & scientific | 2015 |
| Transparent Utility Consultants Limited | Professional & scientific | 2022 |
| Transpec (UK) Limited | Professional & scientific | 2007 |
| Transport 4 Business Limited | Transport & logistics | 2009 |
| Transport Compliance Solutions Ltd | Wholesale & retail | 2022 |
| Transport Enterprises 2000 Limited | Real estate | 1981 |
| Transport Enterprises Limited | Manufacturing | 1999 |
| Transport Halo Limited | Professional & scientific | 2025 |
| Transport Kutz Ltd | Transport & logistics | 2014 |
| Transport Link Services Limited | | 1984 |
| Transport Style Ltd | Transport & logistics | 2024 |
| Transpose Property Limited | Construction | 2010 |
| Transpose Software Limited | Information & communication | 2010 |
| Transpose Software Trustee Ltd | Professional & scientific | 2025 |
| Transpose Supply Limited | Administrative & support | 2015 |
| Transremus Ltd | Transport & logistics | 2018 |
| Transright Services Ltd | Transport & logistics | 2016 |
| Transtek Electronics Ltd | Manufacturing | 2014 |
| Transtrade Link Limited | Wholesale & retail | 1998 |
| Transvera Ltd | Transport & logistics | 2026 |
| Transwarmer Conservatories Ltd | Construction | 2021 |
| Transylvania Engineering Services Ltd | Professional & scientific | 2015 |
| Trapp Holdings Ltd | Hospitality | 2021 |
| Trauma in Mind Ltd | Health & social care | 2020 |
| Travcom Data Solutions Limited | Information & communication | 2025 |
| Travel by Sima Limited | Administrative & support | 2025 |
| Travel Computer Systems (UK) Limited | Information & communication | 2004 |
| Travel Designer Limited | Administrative & support | 2014 |
| Travel Eclipse Limited | Administrative & support | 2017 |
| Travel Haven Ltd | Real estate | 2025 |
| Travel JET Charter Services Limited | Transport & logistics | 2021 |
| Travel JET Direct Limited | Administrative & support | 2023 |
| Travel JET Limited | Administrative & support | 2015 |
| Travel Mart Ltd | Administrative & support | 2010 |
| Travel O Mile BHX Ltd | Administrative & support | 2019 |
| Travel Retail Limited | Wholesale & retail | 2026 |
| Traveler DEV Ltd | Administrative & support | 2021 |
| Travelers Floor UK Limited | Administrative & support | 2025 |
| Travelguest Ltd | Real estate | 2021 |
| Travelhq Ltd | Hospitality | 2021 |
| Travels and Services Ltd | Administrative & support | 2025 |
| Travelwala Limited | Administrative & support | 2019 |
| Trawden Transport Ltd | Transport & logistics | 2014 |
| Trayan Group Ltd | Wholesale & retail | 2025 |
| Traykov’S Wholesale Ltd | Wholesale & retail | 2025 |
| TRB Civil Engineering Ltd | Construction | 2025 |
| TRB Groundworks & Building Contractors Ltd | Construction | 2021 |
| TRC Roofing (Leicester) Limited | Construction | 2019 |
| Trck Ltd | Arts & recreation | 2024 |
| Trcl Civils Ltd | Construction | 2025 |
| Treadmaster Tyres Ltd | Wholesale & retail | 2024 |
| Treadstones Autofit Ltd | Wholesale & retail | 2013 |
| Treasure Nest Limited | Health & social care | 2020 |
| Treasured Builds Ltd | Manufacturing | 2026 |
| Treat Trucks Limited | Hospitality | 2023 |
| Treats&Tiers Limited | Manufacturing | 2025 |
| Treaty of Commerce (Lincoln) Ltd | Hospitality | 2026 |
| Trebor Properties Limited | Real estate | 2004 |
| Tree Life Arboricultural Training Limited | Education | 2018 |
| Tree Tots Day Nursery Leicester Limited | Extraterritorial | 2009 |
| Treehouse Associates Limited | Health & social care | 2014 |
| Treeroots Software Ltd | Information & communication | 2025 |
| Treesa Group Ltd | Administrative & support | 2022 |
| Treetops, Cossington Management Company Limited | Households | 2026 |
| Tregullon Ltd | Wholesale & retail | 2015 |
| Trellows Ltd | Real estate | 2025 |
| Trellows Property Services Ltd | Real estate | 2025 |
| Tremendous Care Agency Ltd | Health & social care | 2016 |
| Tremma Investments Limited | Real estate | 2018 |
| Trend Design Ltd | Construction | 2025 |
| Trend Star Productions Limited | Information & communication | 2024 |
| Trend Technology Ltd | Administrative & support | 2016 |
| Trend Tracker Limited | Extraterritorial | 2018 |
| Trend Trading Limited | Wholesale & retail | 2022 |
| Trendi-Den Ltd | Wholesale & retail | 2025 |
| Trendiimix Ltd | Wholesale & retail | 2025 |
| Trendin Textiles Ltd | Wholesale & retail | 2020 |
| Trendsetters Limited | Wholesale & retail | 2013 |
| Trendy Clothing UK Ltd | Administrative & support | 2001 |
| Trendy Deals Limited | Wholesale & retail | 2025 |
| Trendy Digital Solutions UK Ltd | Manufacturing | 2021 |
| Trendy Fashion Ltd | Wholesale & retail | 2019 |
| Trendy Styles Ltd | Wholesale & retail | 2022 |
| Trendy Teez Limited | Manufacturing | 1993 |
| Trendy Trading Beauty Limited | Wholesale & retail | 2020 |
| Trendz Cart Limited | Wholesale & retail | 2026 |
| Trent Car Sales Ltd | Wholesale & retail | 2022 |
| Trent Furniture Limited | Manufacturing | 2015 |
| Trent Holdings Limited | Financial services | 2018 |
| Trentside Care Limited | Health & social care | 1996 |
| Trenvia UK Ltd | Professional & scientific | 2025 |
| Treswell Dependable Ltd | Hospitality | 2016 |
| Treviso Ltd | Real estate | 2016 |
| Trevorrow Consulting Limited | Administrative & support | 2015 |