| Transylvania Shop Ltd | Wholesale & retail | 2018 |
| Transylvanya Rustic Limited | Hospitality | 2020 |
| Travel Express Consultancy Limited | Hospitality | 2016 |
| Trawl Tours & Travels Ltd | Administrative & support | 2025 |
| Trbs Trustees Limited | Extraterritorial | 2024 |
| Trca Consulting Ltd | Professional & scientific | 2025 |
| Tread Fitness Ltd | Arts & recreation | 2025 |
| Treasure Investment Consultancy Ltd | Real estate | 2020 |
| Treasurehills Services Limited | Public administration | 2021 |
| Tree Fellas Kent Ltd | Other services | 2020 |
| Tree of a Kind Ltd | Administrative & support | 2026 |
| Treehouse Estates and Management Ltd | Real estate | 2022 |
| Trending Rotas Ltd | Health & social care | 2023 |
| Trendy London Ltd | Wholesale & retail | 2021 |
| Trendyblocks Limited | Real estate | 2019 |
| Trevellas Properties Ltd | Real estate | 2023 |
| Trezel Haulage Limited | Transport & logistics | 2025 |
| Trezzy Wholesales Ltd | Wholesale & retail | 2025 |
| TRI Laxmi Ltd | Hospitality | 2025 |
| Triangle Consultancy Limited | Professional & scientific | 2025 |
| Tricknastics Academy Ltd | Education | 2019 |
| Trident Conveyor Systems Ltd | Administrative & support | 2015 |
| Triform Electrical Ltd | Construction | 2019 |
| Triform Ltd | Administrative & support | 2024 |
| Triggerpay Ltd | Information & communication | 2019 |
| Trim& Fade Ltd | Other services | 2022 |
| Trinity Capital (Downton) Limited | Construction | 2021 |
| Trinity Capital Limited | Construction | 2019 |
| Trinity Cleaning & Facilities Management Limited | Administrative & support | 2011 |
| Trinity Crest Ltd | Hospitality | 2026 |
| Trinity Financial Planning Ltd | Professional & scientific | 2023 |
| Trinity Wills and Estate Planning Ltd | Professional & scientific | 2024 |
| Trinzak Limited | Professional & scientific | 2025 |
| Trinze Global Ltd | Information & communication | 2025 |
| Trip Estates Limited | Real estate | 2021 |
| Triple Bricks Ltd | Construction | 2020 |
| Triple Crown Imports Limited | Wholesale & retail | 2009 |
| Triple Hearts Care Ltd | Health & social care | 2023 |
| Triple O Logistics Ltd | Transport & logistics | 2024 |
| Triple Tees Ltd | Education | 2008 |
| Triplem Cakes and Events Ltd | Wholesale & retail | 2025 |
| Tripple O Limited | Information & communication | 2023 |
| Tripplejs Ltd | Public administration | 2022 |
| Tristan London Ltd | Real estate | 2015 |
| Triumph Land Management Ltd | Real estate | 2020 |
| Triumph Multilink Services Ltd | Administrative & support | 2025 |
| Triumph Ventures Limited | Administrative & support | 2009 |
| Trivikram Ltd | Wholesale & retail | 2024 |
| Trixie Rawlinson Limited | Other services | 2010 |
| TRM Waste Contractors Ltd | Water & waste | 2020 |
| Trojan Services UK Limited | Construction | 1994 |
| Trove Link UK Ltd | Wholesale & retail | 2023 |
| TRS Limited | Professional & scientific | 2003 |
| Truck & Plant Commercial Services Ltd | Wholesale & retail | 2012 |
| Truck Align London Ltd | Manufacturing | 2014 |
| Truck Align London Property Company Ltd | Professional & scientific | 2016 |
| Truck Align.Co.Uk Limited | Extraterritorial | 2015 |
| Truck Door Windows Limited | Manufacturing | 2016 |
| TRUCKBASE360 UK Ltd | Information & communication | 2022 |
| Truckbreak Ltd | Wholesale & retail | 2019 |
| True Design and Consulting Ltd | Construction | 2015 |
| True Flower Limited | Administrative & support | 2020 |
| True Goods Ltd | Wholesale & retail | 2026 |
| Trueflux Limited | Information & communication | 2024 |
| Truska Construction Ltd | Construction | 2020 |
| Trust in Safe Hands Ltd | Administrative & support | 2015 |
| Trusted Construction Limited | Construction | 2018 |
| Trustmotion Ltd | Wholesale & retail | 2021 |
| Trustpoint Motors Ltd | Wholesale & retail | 2026 |
| Trustpot Ltd | Information & communication | 2025 |
| Truth Healthcare Consultants Ltd | Health & social care | 2019 |
| TS Unibuild Ltd | Construction | 2025 |
| Ts&B Electrical Ltd | Construction | 2024 |
| TSB Build Ltd | Construction | 2021 |
| TSM Energy Limited | Construction | 2025 |
| TSM Heating Services Ltd | Construction | 2015 |
| Tson Optimal Ltd | Health & social care | 2019 |
| TSP Assetco Limited | Financial services | 2021 |
| TSR Distribution Limited | Hospitality | 2018 |
| TT Reinforcement Ltd | Construction | 2018 |
| TTJ Services Ltd | Administrative & support | 2022 |
| Ttplus Limited | Wholesale & retail | 2017 |
| TTS Service Station Limited | Wholesale & retail | 2025 |
| TTT & Sons Limited | Construction | 2015 |
| Ttwws Ltd | Real estate | 2020 |
| TUC Holdings Limited | Financial services | 2019 |
| Tudmont Ltd | Information & communication | 2017 |
| Tudor Trans Ltd | Transport & logistics | 2024 |
| Tufton Trading Limited | Professional & scientific | 2011 |
| Tuhes Ltd | Wholesale & retail | 2012 |
| Tuhumax Ltd | Administrative & support | 2024 |
| Tulip Developments Ltd | Construction | 2019 |
| Tume's Direct Courier Service Ltd | Transport & logistics | 2026 |
| Tunicksfreshstart Ltd | Health & social care | 2023 |
| Turko Drift Garage Ltd | Wholesale & retail | 2020 |
| Turnaround Support Services Limited | Professional & scientific | 2021 |
| Turner Supplies (GB) Limited | Manufacturing | 2013 |
| Turners Cafe Ltd | Hospitality | 2015 |
| Turners Coffee Shop Ltd | Hospitality | 2025 |
| Turtle Waste Management Limited | Information & communication | 1997 |