| Thomas Scaffolding Limited | Construction | 1999 |
| Thomp Co-Operation Ltd | Hospitality | 2025 |
| Thompson Consultancy Services Limited | Professional & scientific | 2011 |
| Thong Enterprises Limited | Real estate | 1976 |
| Thong Trading Limited | Wholesale & retail | 1987 |
| Thor Civil Engineering Ltd | Construction | 2023 |
| Thorverton Arms Limited | Hospitality | 2019 |
| Three Pillars Micro Ltd | Wholesale & retail | 2017 |
| Threefold Assets Ltd | Real estate | 2023 |
| Threety Ltd | Wholesale & retail | 2019 |
| Thrillion Ltd | Real estate | 2023 |
| Thrive Consultants Ltd | Health & social care | 2024 |
| Thrivewell Health and Lifestyle Coaching Ltd | Other services | 2024 |
| Thsolar Ltd | Construction | 2021 |
| Thurrock Estates Limited | Real estate | 2023 |
| Thushan ENG Ltd | Construction | 2019 |
| Tiario Limited | Wholesale & retail | 2023 |
| Tiario Liverpool Ltd | Wholesale & retail | 2025 |
| Tiario Warrington Ltd | Wholesale & retail | 2025 |
| Ticarat Limited | Transport & logistics | 2015 |
| Tidman Investment & Management Ltd | Financial services | 2023 |
| TIG Edge Allstream (INT.) Ltd | Administrative & support | 2022 |
| Tiga Creative Marketing Limited | Information & communication | 2000 |
| Tikka Central Ltd | Hospitality | 2024 |
| TIL Trans Limited | Transport & logistics | 2014 |
| Tile Station Ltd | Wholesale & retail | 2019 |
| Tilos Asset Holdings Ltd | Financial services | 2025 |
| Timber Windows World Ltd | Construction | 2015 |
| Time 2 Sell Ltd | Wholesale & retail | 2017 |
| Time to Walk Limited | Other services | 2023 |
| Timeless Touch Hair and Beauty Salon Limited | Other services | 2018 |
| Timesurg Healthcare Services Ltd | Health & social care | 2022 |
| Timley Construction Limited | Construction | 2018 |
| Timsol Limited | Health & social care | 2010 |
| Timtam Group Ltd | Construction | 2025 |
| Tindrell Limited | Real estate | 2014 |
| Tiny Treasure Group Ltd | Education | 2026 |
| Tips N Toes Ltd | Other services | 2018 |
| Titan Pro Hair Limited | Wholesale & retail | 2025 |
| Titan Security Ltd | Administrative & support | 2021 |
| Titia Limited | Health & social care | 2022 |
| Tivers Holding Co. Limited | Financial services | 2024 |
| Tivoli Gardens RTM Company Limited | Households | 2025 |
| Tivoli Residents Committee RTM Company Limited | Households | 2025 |
| TJD Property Consultancy Ltd | Professional & scientific | 2024 |
| TJM Computing UK Limited | Administrative & support | 2007 |
| TJP Building Services Ltd | Construction | 2026 |
| TJP Homes Limited | Construction | 2020 |
| TK Construction Consultants Ltd | Professional & scientific | 2020 |
| TK Premier Holdings Ltd | Real estate | 2017 |
| Tkdelights Ltd | Manufacturing | 2021 |
| Tkdoms Limited | Professional & scientific | 2015 |
| Tkodimac Ltd | Other services | 2025 |
| TLB Cobham Ltd | Hospitality | 2025 |
| TLC House Keeping Services Ltd | Other services | 2023 |
| TLG Services Ltd | Construction | 2021 |
| TLN Contract Services Limited | Professional & scientific | 2014 |
| Tlna Engineering Services Ltd | Administrative & support | 2007 |
| TLS (Kent) Limited | Manufacturing | 2019 |
| TM Erections Ltd | Construction | 2018 |
| TM Staff Services Ltd | Transport & logistics | 2021 |
| Tmash Ltd | Hospitality | 2017 |
| TMT Trans Ltd | Transport & logistics | 2019 |
| TNH Accountants Ltd | Professional & scientific | 2012 |
| TNL Global Ltd | Other services | 2024 |
| Tnskassessmentservices Limited | Health & social care | 2021 |
| Toastwich Ltd | Hospitality | 2025 |
| Tobilu UK Ltd | Health & social care | 2026 |
| Toby George Dream Builds Ltd | Construction | 2026 |
| Tocco UK Division Limited | Construction | 2013 |
| Toda Properties Limited | Real estate | 2019 |
| Toggs Hair Ltd | Other services | 2005 |
| Tokyo Productions Limited | Information & communication | 2011 |
| Tolizdan Limited | Health & social care | 2014 |
| Tollgate Homes Lower Higham Limited | Construction | 2025 |
| Tolstar Civils Limited | Construction | 2014 |
| TOM and JON Ltd | Construction | 2023 |
| TOM Communications Ltd | Other services | 2023 |
| TOM Stone Ltd | Construction | 2020 |
| Tom's Motorbike Export Ltd | Wholesale & retail | 2019 |
| Tominiavos Ltd | Transport & logistics | 2025 |
| Tomit Limited | Wholesale & retail | 2024 |
| Tomson Property Developments Limited | Real estate | 2004 |
| Tomson Stores Limited | Wholesale & retail | 2001 |
| Tomy Kitchens Ltd | Construction | 2019 |
| Tonidol (UK) Limited | Real estate | 2004 |
| Tonidol Properties Limited | Real estate | 2020 |
| Tony Barnes Engineering Ltd | Construction | 2026 |
| Tony Wint Rail Solutions Ltd | Construction | 2016 |
| Tool Labs Limited | Manufacturing | 2025 |
| Toor Brothers Properties Ltd | Real estate | 2014 |
| Toors Plumbing and Heating Ltd | Construction | 2025 |
| Top Fire Systems Ltd | Other services | 2025 |
| Top Hub Ltd | Wholesale & retail | 2025 |
| Top Rubbish Removal Ltd | Water & waste | 2023 |
| Top Vendors Ltd | Professional & scientific | 2018 |
| Toperfolg Ltd | Other services | 2024 |
| Topolewski Limited | Construction | 2023 |
| Tops the LOT CP Limited | Construction | 2014 |
| TOR Marine Services Ltd | Other services | 2014 |