| Thewoodworx Limited | Manufacturing | 2022 |
| Theworkworks Limited | Wholesale & retail | 2021 |
| Think Motorbike Limited | Wholesale & retail | 2019 |
| Thinking Bytes Ltd | Extraterritorial | 2023 |
| Thinksmart Electronics Trading UK Ltd | Wholesale & retail | 2023 |
| Thorfit Ltd | Wholesale & retail | 2024 |
| Three Akenside Road Limited | Households | 1984 |
| Through the Roof Charitable Trust | Information & communication | 2001 |
| Thrust Investment Ltd | Construction | 2019 |
| Ticketpool Limited | Wholesale & retail | 2012 |
| Tickets Made Simple Ltd | Administrative & support | 2024 |
| Tidal Capital Ltd | Real estate | 2019 |
| Tidy Touche (UK) Ltd | Administrative & support | 2024 |
| Time Homes Real Estate Limited | Real estate | 2024 |
| Timelessxcollection Limited | Wholesale & retail | 2024 |
| Timeline Entertainment Ltd | Information & communication | 2025 |
| Timpal Healthcare Ltd | Wholesale & retail | 2025 |
| Tinytriangle Ltd | Real estate | 2020 |
| TIP Top Drive Ltd | Education | 2018 |
| TK Memories Ltd | Professional & scientific | 2026 |
| TKG Corporate Ventures UK Ltd | Other services | 2023 |
| TKM Operations Ltd | Transport & logistics | 2025 |
| Tksa Trading Ltd | Transport & logistics | 2016 |
| Tksh Ltd | Health & social care | 2018 |
| TLB UK Property Limited | Real estate | 2023 |
| TLC Homecare Ltd | Health & social care | 2025 |
| Tlexx Services Ltd | Hospitality | 2021 |
| TMC Digicore UK Limited | Information & communication | 2025 |
| TMG Food Ltd | Manufacturing | 2025 |
| TMR Holdings Ltd | Real estate | 2023 |
| Tmvv Ltd | Real estate | 2022 |
| TN GAS & Heating Ltd | Construction | 2018 |
| Tnawaz Ltd | Transport & logistics | 2022 |
| TNK Services Ltd | Wholesale & retail | 2013 |
| TOG Taste of German Limited | Hospitality | 2025 |
| Tolik Logistics Ltd | Transport & logistics | 2026 |
| Tollyville Limited | Real estate | 2022 |
| Tomwlaurent Limited | Professional & scientific | 2023 |
| Toniko Ltd | Construction | 2018 |
| Tony's Butchers 1 Ltd | Wholesale & retail | 2023 |
| Tony's Grocers Ltd | Wholesale & retail | 2018 |
| Tooting & Mitcham Community Sports Club Ltd | Arts & recreation | 2011 |
| Tooting & Mitcham United FC Members Limited | Arts & recreation | 2005 |
| Top Fish Bar Ltd | Hospitality | 2018 |
| Top House Conferences Limited | Professional & scientific | 2025 |
| Top Kitchen Worktops & Tiles Ltd | Wholesale & retail | 2020 |
| Top Resource Solutions Ltd | Administrative & support | 2024 |
| Top Shop Marketing Ltd | Information & communication | 2024 |
| Top Star Services Ltd | Transport & logistics | 2016 |
| Top Wine Spirits Limited | Administrative & support | 2010 |
| Topaz Creations Ltd | Construction | 2025 |
| Topaz Phoenetix Ltd | Financial services | 2025 |
| Topbuild Construction Ltd | Construction | 2014 |
| Topextend Design & Build Ltd | Construction | 2026 |
| TOQ Drive Ltd | Transport & logistics | 2019 |
| Tori’S Pure Beauty & TAN Ltd | Other services | 2025 |
| Toro Fintel Group Ltd | Information & communication | 2024 |
| Toro LRL Limited | Households | 2024 |
| Total Gblerkpo Ltd | Administrative & support | 2019 |
| Totalcare Trading Ltd | Health & social care | 2019 |
| Touchstone Solutions Ltd. | Manufacturing | 2005 |
| Toughits Limited | Wholesale & retail | 2020 |
| Town and Country CPT Limited | Wholesale & retail | 2009 |
| Tracxn UK Ltd | Households | 2024 |
| Trade Linkers Ltd | Other services | 2016 |
| Trade Worlwide Ltd | Wholesale & retail | 2021 |
| Tradeen Corp Limited | Wholesale & retail | 2021 |
| Tradewise Enterprise UK Ltd | Wholesale & retail | 2023 |
| Trading Guru Ltd | Other services | 2023 |
| Trans Group International Ltd | Transport & logistics | 2023 |
| Transbridge Limited | Professional & scientific | 1999 |
| Transcend AI Limited | Information & communication | 2025 |
| Transiva Investment UK Ltd | Wholesale & retail | 2026 |
| Traschic Ltd | Wholesale & retail | 2021 |
| Travel Town Ltd | Administrative & support | 2024 |
| Treadstone Print & Textiles Limited | Administrative & support | 2012 |
| Treat & Cure Holdings Ltd | Financial services | 2020 |
| Trebor-D Limited | Construction | 2022 |
| Tree Star Development London Ltd | Administrative & support | 2025 |
| Tree Star Developments Ltd | Administrative & support | 2018 |
| Trend Barbers Ltd | Other services | 2025 |
| Trend Invest UK Ltd | Information & communication | 2009 |
| Trendoria Ltd | Wholesale & retail | 2025 |
| Trendy Captain Ltd | Wholesale & retail | 2025 |
| Trent Car Rental Ltd | Hospitality | 2023 |
| Tribal Knights Limited | Wholesale & retail | 2021 |
| Trident Building Ltd | Construction | 2023 |
| Trigri Holdings Limited | Other services | 2023 |
| Trinity Carpentry and Building Ltd | Construction | 2017 |
| Trinity Media and Events Ltd | Information & communication | 2024 |
| Trio Protection Limited | Administrative & support | 2015 |
| Truckbro Technologies Ltd | Wholesale & retail | 2025 |
| True Smart Commerce Limited | Wholesale & retail | 2025 |
| True View Consulting Ltd | Information & communication | 2025 |
| Trust Autocare UK Limited | Transport & logistics | 2013 |
| Trust BOB Ltd | Construction | 2022 |
| Trust Heating Services Ltd | Construction | 2019 |
| TSA London Trading Limited | Administrative & support | 2016 |
| Tsang's Family Ltd | Households | 2019 |
| TST Outdoor Toys Ltd | Wholesale & retail | 2011 |