| Trident Electrical Solutions Ltd | Construction | 2019 |
| Trident Fire Ltd | Construction | 2020 |
| Trident Line (UK) Ltd | Transport & logistics | 2023 |
| Trident Marketing Anglia Limited | Professional & scientific | 2010 |
| Trident Plumbing, Heating and Electrical Limited | Manufacturing | 2000 |
| Triiit Ltd | Professional & scientific | 2025 |
| Triking Sports Cars Limited | Manufacturing | 2009 |
| Trikuta Ventures Limited | Information & communication | 2026 |
| Trililion Limited | Construction | 2013 |
| Trillium Financial Planning Ltd. | Financial services | 2001 |
| Trimtech AI Ltd | Information & communication | 2026 |
| Trinamics Software Ltd | Information & communication | 2016 |
| Trinity (B) Limited | Real estate | 2007 |
| Trinity (E) Limited | Real estate | 2019 |
| Trinity (F) Limited | Real estate | 2007 |
| Trinity College (CSP) Limited | Real estate | 1997 |
| Trinity Consulting EA Limited | Construction | 2023 |
| Trinity Conveyancing Ltd | Professional & scientific | 2010 |
| Trinity Cups Limited | Manufacturing | 2024 |
| Trinity Farrier Services Ltd | Agriculture & fishing | 2018 |
| Trinity GEM Ltd | Construction | 2024 |
| Trinity Legal Services Ltd | Professional & scientific | 2005 |
| Trinity Process and Pipeline Services Ltd | Administrative & support | 2020 |
| Trinity Property Developments Ltd | Real estate | 2016 |
| Trinity Sales Consultants Limited | Administrative & support | 2013 |
| Trinity Solutions (East Anglia) Limited | Education | 2020 |
| Trio's at ST Peter's Limited | Hospitality | 2021 |
| Trio's Catering & Event Planning Limited | Hospitality | 2011 |
| Trio's Tipples Limited | Hospitality | 2019 |
| Triospark Cleaning Limited | Administrative & support | 2025 |
| Trip Travel Ltd | Wholesale & retail | 2019 |
| Triple 'a' Services Limited | Wholesale & retail | 2008 |
| Triple 888 Properties Ltd | Real estate | 2017 |
| Triple a Electrical Limited | Construction | 2022 |
| Triple Bottom Line Accounting Limited | Professional & scientific | 2009 |
| Triple Bottom Line Education Limited | Professional & scientific | 2022 |
| Triple E Services Ltd | Professional & scientific | 2020 |
| Triple J Private Hire Limited | Transport & logistics | 2013 |
| Triple NET Property 1 Limited | Financial services | 2013 |
| Triple NET Property 3 Limited | Financial services | 2013 |
| Triple R Driving School Ltd | Education | 2023 |
| Triple Stars Acrobatics Club Ltd | Arts & recreation | 2023 |
| Triple Threat Media Limited | Professional & scientific | 2020 |
| Triple Threat Stage School LLP | | 2025 |
| Tripleq Limited | Construction | 2002 |
| Tripmatch Ltd | Information & communication | 2025 |
| Trirock Properties UK Limited | Real estate | 2012 |
| Trivedi Family Capital Ltd | Real estate | 2023 |
| Trivedi Group Investments Limited | Real estate | 2023 |
| Trivedi Holdings Ltd | Real estate | 2017 |
| Trivedi Property Development Ltd | Construction | 2016 |
| Trixel Holdings Ltd | Extraterritorial | 2022 |
| Trolley Holdings Ltd | Extraterritorial | 2021 |
| Tropho Ltd | Real estate | 2022 |
| Tropic Biosciences UK Limited | Agriculture & fishing | 2016 |
| Tropic Supply UK Limited | Agriculture & fishing | 2026 |
| Tropical Landscaping Ltd | Administrative & support | 2021 |
| Tropical Management Services Ltd | Hospitality | 2022 |
| Troshun Holdings Limited | Professional & scientific | 2012 |
| Trott OFF Limited | Households | 2021 |
| TROUBL3MAKER Productions CIC | Information & communication | 2025 |
| Trowse House Management Company Limited | Households | 1992 |
| Trowse Millgate Residents Association Limited | Real estate | 2000 |
| Troy Techno Ltd | Information & communication | 2023 |
| TRS Consultants Ltd | Hospitality | 2019 |
| TRS21 Investment Group Ltd | Professional & scientific | 2026 |
| TRT 20 Ltd | Administrative & support | 2026 |
| Tru-Form Limited | Extraterritorial | 1996 |
| Truckcraft (Nottingham) Limited | Transport & logistics | 2000 |
| True Balance Equestrian Ltd | Education | 2026 |
| True Care Services PVT Ltd | Health & social care | 2022 |
| True Colour Foundation CIC | Education | 2020 |
| True Colour Transformations Ltd | Education | 2017 |
| True Concept Design Ltd | Professional & scientific | 2023 |
| True Love Creative Ltd | Other services | 2024 |
| True North Media Ltd | Information & communication | 2020 |
| True Reflections Limited | Other services | 2014 |
| Truestone Paving & Driveways Ltd | Administrative & support | 2025 |
| Truflex Home Improvements Ltd | Construction | 2025 |
| Truflex Ltd | Administrative & support | 2017 |
| Trum Ltd | Wholesale & retail | 2025 |
| Trust Care Agency Limited | Health & social care | 2014 |
| Trustay Property Group Ltd | Hospitality | 2026 |
| Trusted Cars Norwich Ltd | Wholesale & retail | 2023 |
| Trusted Cleaning Holdings Limited | Administrative & support | 2021 |
| Trusted Medical Ltd | Health & social care | 2020 |
| Trusted Property Ltd | Real estate | 2021 |
| Trusted UK Business Solutions Limited | Information & communication | 2013 |
| Trustedge Security Ltd | Administrative & support | 2025 |
| Trydeal 2002 Limited | Real estate | 2002 |
| Tryfold Ltd | Information & communication | 2021 |
| Trysull Balti Limited | Hospitality | 2019 |
| TS Fasteners UK Ltd | Wholesale & retail | 2021 |
| TS Financial Planning Ltd | Financial services | 2021 |
| TS Transport and Security Ltd | Agriculture & fishing | 2023 |
| TS2 Micro Ltd | Extraterritorial | 2000 |
| TSE Automotive Limited | Wholesale & retail | 2016 |
| TSH Roofing Contractors Ltd | Construction | 2021 |
| TSH Roofing Materials Ltd | Extraterritorial | 2021 |
| TSI Steel Services Ltd | Construction | 2025 |