| Tiptop Club Ltd | Arts & recreation | 2015 |
| TIS Training & Consultancy Limited | Professional & scientific | 2015 |
| Titan Machinery LP | | 2016 |
| Titanium Security UK Ltd | Administrative & support | 2017 |
| Titen Limited | Construction | 2019 |
| Titus Newsome (Immingham) Limited | Transport & logistics | 1972 |
| Titus Newsome Limited | Transport & logistics | 1964 |
| TJ Supplements Limited | Wholesale & retail | 2019 |
| TJB Projects Limited | Professional & scientific | 2016 |
| TJC Solutions Limited | Financial services | 2010 |
| TK Cleaning Services Ltd | Administrative & support | 2019 |
| TK Timber Products Ltd | Wholesale & retail | 2019 |
| TLC Trade Frames Ltd | Construction | 2007 |
| Tmav Ltd | Professional & scientific | 2025 |
| TML Aaron Limited | Transport & logistics | 2026 |
| Tml-Offshore-Contractors Ltd | Administrative & support | 2023 |
| Tnwproducts Limited | Wholesale & retail | 2025 |
| Tofan Trans Ltd | Transport & logistics | 2023 |
| Together WE Shine CIC | Other services | 2025 |
| TOM Fisher Joinery Ltd | Construction | 2024 |
| TOM Plumb Plumbing & Heating Limited | Construction | 2022 |
| TOM Prime Ltd | Wholesale & retail | 2022 |
| Tomfam Engineering Limited | Administrative & support | 2007 |
| Tomi TIR Transport Ltd | Transport & logistics | 2025 |
| Tommy Ryan Ltd | Administrative & support | 2026 |
| Tommy Sant Car Care Limited | Wholesale & retail | 2003 |
| Tom`S Bargain Centre Limited | Wholesale & retail | 2003 |
| Tongie Ltd | Real estate | 2021 |
| Toni's Homewares and Interiors Ltd | Wholesale & retail | 2025 |
| Tonward Limited | Real estate | 1945 |
| Tony Heath Construction Ltd | Construction | 2023 |
| Tony Jackson Property Services Limited | Construction | 2017 |
| Tony Smith Domestic Energy Assessor Limited | Administrative & support | 2007 |
| Toog Ltd | Administrative & support | 2020 |
| Toops Tidy Gardens Ltd | Administrative & support | 2012 |
| Top BIN Management Limited | Extraterritorial | 2025 |
| Top Class Properties UK Ltd | Real estate | 2016 |
| Top Corner Store Ltd | Wholesale & retail | 2025 |
| Top Farm Gardens Management Co Ltd | Households | 2019 |
| Top Notch Groundwork’S and Building Services Limited | Construction | 2025 |
| Top Shop Fisheries Limited | Hospitality | 2008 |
| Top Shop Minimarket 165 Ltd | Wholesale & retail | 2025 |
| Top Town 1 Limited | Wholesale & retail | 2025 |
| Top UK Barber Limited | Other services | 2023 |
| TOP2BOTTOM Domestic & Commercial Cleaning. Ltd | Administrative & support | 2019 |
| Topcon Building (Holdings) Limited | Financial services | 2020 |
| Topcon Building Limited | Construction | 2015 |
| Topcon Construction Holdings Limited | Financial services | 2015 |
| Topcon Construction Limited | Construction | 2010 |
| Topcon Limited | Financial services | 2026 |
| Toplift Cranes Limited | Construction | 2018 |
| Toppoint Ltd | Transport & logistics | 2019 |
| Topsy Telematics Limited | Construction | 2026 |
| Toptubs Lincolnshire Ltd | Wholesale & retail | 2025 |
| Tora Properties (GB) Limited | Households | 1994 |
| Torbay Park (Scartho) Management Company Limited | Households | 2024 |
| Torr Engineering Limited | Construction | 2009 |
| Torvix UK Limited | Wholesale & retail | 2025 |
| Total Calibration & Offshore Services Ltd | Professional & scientific | 2020 |
| Total Food Machinery Limited | Manufacturing | 2015 |
| Total Insulation Services Limited | Construction | 2008 |
| Total JOB Solutions Limited | Professional & scientific | 2014 |
| Total Maintenance Solutions (East) Ltd | Manufacturing | 2017 |
| Total Signs and Graphics (Corporate) Limited | Financial services | 2021 |
| Total Signs and Graphics (Holdings) Limited | Professional & scientific | 2013 |
| Total Signs and Graphics Limited | Manufacturing | 2006 |
| Total Trade Cars Limited | Wholesale & retail | 2020 |
| Total Window Shutters Ltd | Construction | 2019 |
| Totally Thrippleton Limited | Real estate | 2023 |
| Tothill Farmers Limited | Agriculture & fishing | 1977 |
| Touchwood Ltd | Wholesale & retail | 2025 |
| Toulson Construction Limited | Construction | 2014 |
| Tower Staff Construction Ltd | Administrative & support | 2011 |
| Town Barber (Grimsby) Limited | Other services | 2025 |
| TPG Technology Limited | Administrative & support | 2015 |
| Tracy DI Carlo Ltd | Information & communication | 2018 |
| Trade Kitchens and Bedrooms GY Limited | Manufacturing | 2019 |
| Trade Price Sofas (Merthyr Tydfil) Limited | Wholesale & retail | 2015 |
| Trade TX Limited | Wholesale & retail | 2025 |
| Tradelock.Global Ltd | Information & communication | 2025 |
| Trademark Property Management Ltd | Real estate | 2021 |
| Trademark Services Ltd | Professional & scientific | 2019 |
| Traditional Gates Limited | Manufacturing | 2014 |
| Traditional Joiners and Carpenters Limited | Manufacturing | 2001 |
| Traditional Living Ltd | Wholesale & retail | 2013 |
| Traditional Steel Limited | | 2003 |
| Trafalgar Properties Lincs Ltd | Real estate | 2019 |
| Trafford Management & Engineering Services Limited | Construction | 2016 |
| Trans Sonic Ltd | Transport & logistics | 2017 |
| Transafe (Training) Limited | Extraterritorial | 2018 |
| Transform Fitness Limited | Arts & recreation | 2021 |
| Translogix Limited | Transport & logistics | 2026 |
| Transport Direct Limited | Transport & logistics | 2003 |
| Transport Speed Ltd | Transport & logistics | 2026 |
| Travel by YOU Ltd. | Administrative & support | 2020 |
| Travel Dreamz Limited | Administrative & support | 2017 |
| Travel Forever Competitions Limited | Wholesale & retail | 2025 |
| TRB Access Limited | Construction | 2017 |
| Treatment Club Limited | Other services | 2019 |
| Tredawn Properties Limited | Extraterritorial | 2003 |