| Treyd Limited | Financial services | 2023 |
| TRH Properties Limited | Real estate | 2021 |
| Triad Empress Estate Ltd | Real estate | 2025 |
| Trials Pro UK Ltd | Health & social care | 2024 |
| Triangle Capital Partners Ltd | Real estate | 2024 |
| Tribate Light Limited | Professional & scientific | 2025 |
| Tribe of Travelers Ltd | Administrative & support | 2024 |
| Tribeca Consultants Ltd | Professional & scientific | 2018 |
| Tribyte Systems Limited | Information & communication | 2013 |
| Tricolom Holdings Ltd | Professional & scientific | 2008 |
| Tricolom Limited | Professional & scientific | 2004 |
| Tricon Investments Limited | Real estate | 2019 |
| Tricon Print Solutions Limited | Manufacturing | 2002 |
| Tricop Ltd | Wholesale & retail | 2022 |
| Trident Care Ltd | Health & social care | 2026 |
| Trident Flooring Limited | Construction | 2020 |
| Trident Guard Security Ltd | Administrative & support | 2023 |
| Tridentwealthbusiness Limited | Wholesale & retail | 2026 |
| Tridevi PVT Ltd | Hospitality | 2025 |
| Tridevi Trading Group Ltd | Real estate | 2019 |
| Trif Transport Ltd | Transport & logistics | 2020 |
| Trifall-X Ltd | Transport & logistics | 2021 |
| Trifibre Group Limited | Administrative & support | 2006 |
| Trifibre Limited | Manufacturing | 1985 |
| Trigeco Ltd | Manufacturing | 2019 |
| Triggerbest Limited | Construction | 1985 |
| Triggerbyte Ltd | Information & communication | 2019 |
| Triiumph Construction Ltd | Construction | 2021 |
| Trim Technique Holdings Limited | Financial services | 2021 |
| Trim-Technique Ltd | Wholesale & retail | 2003 |
| Trimas Corporation Limited | Financial services | 1996 |
| Trimas Packaging Limited | Manufacturing | 1934 |
| Trimas UK Aerospace Holdings Limited | Financial services | 2014 |
| Trimdon Healthcare Limited | Wholesale & retail | 2023 |
| Trimedica Medtek Limited | Manufacturing | 2013 |
| Trimex Investments Limited | Financial services | 2006 |
| Trims & Threads Ltd | Wholesale & retail | 2025 |
| Trims by Trevaa Ltd | Other services | 2021 |
| Trinderbox Limited | Information & communication | 2005 |
| Trineetee Services Ltd | Hospitality | 2022 |
| Trinetra ( Leicester) Ltd | Real estate | 2024 |
| Tringford Logistics Ltd | Transport & logistics | 2014 |
| Triniti UK Group Ltd | Hospitality | 2022 |
| Trinity Autos Limited | Wholesale & retail | 2017 |
| Trinity House Care Limited | Health & social care | 2016 |
| Trinity House Property Limited | Real estate | 2016 |
| Trinity Medical Ltd | Health & social care | 2018 |
| Trinity Relocation Company Ltd | Hospitality | 2023 |
| Triontotte Limited | Wholesale & retail | 2022 |
| Tripathi Properties Ltd | Real estate | 2021 |
| Tripec Ltd | Wholesale & retail | 2020 |
| Triple a Education Limited | Education | 2025 |
| Triple C Leicester Ltd | Wholesale & retail | 2025 |
| Triple Helix Life Coaching Ltd | Health & social care | 2021 |
| Triple N Van Hire Ltd | Real estate | 2025 |
| Triple R Paintworx Ltd | Wholesale & retail | 2024 |
| Triple S Clutch & Brake Services Limited | Wholesale & retail | 1993 |
| Triple SM Limited | Wholesale & retail | 2016 |
| Triple TEE Fast Connect Ltd. | Financial services | 2018 |
| Triple Web Media Limited | Information & communication | 2012 |
| Triple- a Logistics Ltd | Transport & logistics | 2019 |
| Trippet Holland Ltd | Wholesale & retail | 2025 |
| Triptyk Limited | Professional & scientific | 2010 |
| Trishul (Leicester) Ltd | Real estate | 2024 |
| Trishul Core Ltd | Wholesale & retail | 2025 |
| Trison Estates Limited | Real estate | 2014 |
| Trison Estates Topco Limited | Real estate | 2022 |
| Trison Ltd | Real estate | 2018 |
| Trison Medics Ltd | Health & social care | 2019 |
| Tristar Investments Limited | Wholesale & retail | 2019 |
| Tristar IT Ltd | Administrative & support | 2021 |
| Tristar Security Solutions Limited | Administrative & support | 2020 |
| Trisul Property Ltd | Real estate | 2024 |
| Triumph IS Mine Ltd | Professional & scientific | 2023 |
| Triumph Legal Advice Services Ltd | Professional & scientific | 2014 |
| Triumph Needle Co Limited | Manufacturing | 1978 |
| Triumph Recovery and Transportation Ltd | Manufacturing | 2024 |
| Triumphal Ltd | Arts & recreation | 2019 |
| Trivam Ltd | Real estate | 2024 |
| Trivis Components Ltd | Manufacturing | 2026 |
| Trixnet One Ltd | Wholesale & retail | 2020 |
| TRK Consultancy Ltd | Health & social care | 2022 |
| TRL Restaurant Ltd | Hospitality | 2026 |
| TRM Engineering & Human Factors Ltd | Professional & scientific | 2018 |
| TRM Properties Limited | Real estate | 1999 |
| Trnbll Consultants Ltd | Professional & scientific | 2020 |
| Trofin Andrey Limited | Transport & logistics | 2016 |
| Trojnacki Transport Ltd | Transport & logistics | 2019 |
| Trojon Roller Doors Ltd | Real estate | 2024 |
| Trombo Limited | Construction | 2019 |
| Tron Legacy Limited | Arts & recreation | 2018 |
| Troon Cars Ltd | Wholesale & retail | 2007 |
| Trophies Plus Medals Ltd | Wholesale & retail | 2019 |
| Trophy Circle Agency Limited | Information & communication | 2026 |
| Tropical Exotic Foods Ltd | Wholesale & retail | 2020 |
| Tropical Produce Limited | Wholesale & retail | 2015 |
| Tropikol Ltd | Wholesale & retail | 2025 |
| Tropimart Limited | Wholesale & retail | 2024 |
| Trotters Independent HOG Roast Limited | Hospitality | 2013 |
| Trove Clothing Ltd | Manufacturing | 2024 |