| Thompson Mitchell Group Ltd | Construction | 2022 |
| Thompson Welding & Construction Ltd | Construction | 2017 |
| Three SJK (UK) Ltd | Hospitality | 2025 |
| Three Sons Fire Safety Ltd | Construction | 2025 |
| Thurles Limited | Administrative & support | 2019 |
| Thurstan Redding Estates Limited | Real estate | 2020 |
| Tickner Tracks Limited | Construction | 2016 |
| Tickners Structural & Finish Carpentry Ltd | Construction | 2024 |
| Ticktekk Limited | Professional & scientific | 2011 |
| TIE Solutions Limited | Construction | 2017 |
| Tiger Tracks Ltd | Other services | 2025 |
| Tila Tila Ltd | Hospitality | 2025 |
| Tile Brokerage International Limited | Wholesale & retail | 2023 |
| Till Projects Limited | Professional & scientific | 2024 |
| Tilli Limited | Administrative & support | 2012 |
| Timbertrain Music Limited | Administrative & support | 2006 |
| Timday Consulting UK Ltd | Professional & scientific | 2014 |
| Time for Flowers (Kent) Limited | Wholesale & retail | 2019 |
| Titan Jewellery Limited | Wholesale & retail | 2012 |
| Tjbutcher Ltd | Financial services | 2025 |
| TJG Ecommerce Ltd | Wholesale & retail | 2024 |
| TJH Property Limited | Real estate | 2023 |
| TJP Management Consulting Limited | Professional & scientific | 2010 |
| TK & Son's Property Company Limited | Hospitality | 2024 |
| TK Commodity Trading Limited | Wholesale & retail | 2026 |
| TKP Partners Limited | Health & social care | 2012 |
| TLC Home Care Solutions Ltd | Health & social care | 2014 |
| TM Electrical London Ltd | Construction | 2020 |
| Tmck Building Services Limited | Construction | 2024 |
| TMS Cleaners Limited | Other services | 2009 |
| TN Talent Ltd | Administrative & support | 2019 |
| TNS Haulage Ltd | Transport & logistics | 2019 |
| TNT Mastic Sealants Ltd | Administrative & support | 2023 |
| Toby Coles Ltd | Arts & recreation | 2014 |
| Toby Snuggs TV Ltd | Administrative & support | 2023 |
| TOM Nunn Electrical Ltd | Administrative & support | 2023 |
| Tom's Butchers Limited | Wholesale & retail | 2021 |
| Tommy Shelby Grooming Limited | Extraterritorial | 2019 |
| Tonara Foods Limited | Hospitality | 2020 |
| Tone Group Limited | Financial services | 2002 |
| Tone Scaffolding Limited | Extraterritorial | 2002 |
| Tone Scaffolding Services Limited | Construction | 1999 |
| Top Cuts Sidcup Ltd | Other services | 2023 |
| Top Doggy Limited | Manufacturing | 2025 |
| Top Logistics Crew Ltd | Transport & logistics | 2016 |
| Top Tier Developments Ltd | Construction | 2023 |
| Topmark Global Limited | Administrative & support | 2023 |
| Topmark Sports Coaching Limited | Education | 2011 |
| Topvita Ltd | Wholesale & retail | 2025 |
| Torcon PM Limited | Construction | 2023 |
| Torn Page Games Limited | Information & communication | 2015 |
| Tortuga Software Limited | Information & communication | 2015 |
| Toscana Restaurant Ltd | Hospitality | 2011 |
| Total Fire Protection Ltd | Public administration | 2021 |
| Tots in Sport (Kent) Ltd | Education | 2015 |
| Tower Bridge Road Ltd | Hospitality | 2019 |
| Towich Ltd | Real estate | 2023 |
| Town Centre Holdings Limited | Financial services | 2017 |
| Town Centre Inns Limited | Wholesale & retail | 2002 |
| Town Centre Limited | Real estate | 2019 |
| Toxo Group Ltd | Construction | 2024 |
| TP Residential Ltd | Construction | 2025 |
| TPL Electrical Limited | Construction | 2025 |
| Tpsa Limited | Professional & scientific | 2009 |
| TR Escalators Ltd | Manufacturing | 2026 |
| Traban Groundworks Ltd | Construction | 2023 |
| Tracey L Murray Limited | Health & social care | 2023 |
| Track Air Consultants Limited | Construction | 2019 |
| Trackway Consult Limited | Professional & scientific | 2025 |
| Traction Power Resources Ltd | Construction | 2020 |
| Tradingpoker Limited | Financial services | 2025 |
| Trafalgar Property Investment Limited | Real estate | 2019 |
| Trakia Lift Ltd | Construction | 2006 |
| Transcar Enterprise Holdings Limited | Financial services | 2024 |
| Transcar Projects (Holdings) Ltd | Financial services | 1996 |
| Transcar Projects Limited | Transport & logistics | 1977 |
| Transcar Property LLP | | 2009 |
| Transformations Therapy Service Limited | Health & social care | 2019 |
| Transforming Communities Limited | Education | 2025 |
| Transforming Conservatories Ltd | Construction | 2021 |
| Transit Productions Ltd | Arts & recreation | 2024 |
| Translantic Development Ltd | Professional & scientific | 2014 |
| Translation Pro Ltd | Professional & scientific | 2022 |
| Trave Construction Ltd | Construction | 2018 |
| Treloar Eyecare Limited | Professional & scientific | 2021 |
| Trend Setters Beauty Ltd | Health & social care | 2021 |
| Trident Damp Ltd | Construction | 2012 |
| Trilateral IT Limited | Administrative & support | 2008 |
| Trinity Stewart Limited | Professional & scientific | 2020 |
| Tristone Property Consultancy Ltd | Real estate | 2025 |
| Triumph Building Services Ltd | Construction | 2023 |
| Tromsostan Limited | Real estate | 1975 |
| Tropical Blinds Limited | Manufacturing | 1996 |
| Trotters Independent Tradesmen Ltd | Construction | 2013 |
| Troubleshoot Recordings Ltd | Administrative & support | 2021 |
| True Compliance Limited | Information & communication | 2016 |
| Truesourceuk Limited | Administrative & support | 2021 |
| Trumps Hickstead Limited | Construction | 2019 |
| Trustscaff Ltd | Construction | 2026 |
| TS Woods Logistics Ltd | Manufacturing | 2019 |