| Torrington Drive, South Harrow Management Limited | Households | 1986 |
| Tort Services Ltd | Professional & scientific | 2026 |
| Torus Estates Limited | Real estate | 2018 |
| Torver Road RTM Company Limited | Households | 2017 |
| TOS Bars (Chessington) Ltd | Hospitality | 2025 |
| TOS Bars (Victoria) Ltd | Hospitality | 2025 |
| TOS Payroll Services Limited | Administrative & support | 2025 |
| Toscaviva Ltd | Transport & logistics | 2012 |
| TOSTI1820 UK Ltd | Wholesale & retail | 2022 |
| Tota Tattoos Limited | Arts & recreation | 2014 |
| Total Care Estate Builders Ltd | Construction | 2025 |
| Total Connects IT Solutions Ltd | Information & communication | 2022 |
| Total Financial Management Ltd | Professional & scientific | 2020 |
| Total Hybrid Solutions Ltd | Other services | 2015 |
| Total Market Access Solutions Ltd. | Professional & scientific | 2012 |
| Total Medcare (UK) Limited | Wholesale & retail | 2012 |
| Total Medcare Limited | Wholesale & retail | 2009 |
| Total Properties Management Ltd | Real estate | 2022 |
| Total Property Solutions & Services Ltd | Construction | 2020 |
| Total Quality Concept Accountancy Ltd | Professional & scientific | 2003 |
| Total&Co Ltd | Professional & scientific | 2025 |
| Totalbrief Limited | Real estate | 1992 |
| Totalise Property Ltd | Real estate | 2019 |
| Totally Floored Limited | Construction | 2002 |
| Totally Glass Limited | Manufacturing | 2015 |
| Totally Interactive Limited | Information & communication | 2009 |
| Totally Investments Ltd | Real estate | 2014 |
| Totally Pharmacy Ltd | Wholesale & retail | 2009 |
| Totaltec Limited | Professional & scientific | 2023 |
| Totalten Ltd | Administrative & support | 2017 |
| Totem Global Ltd | Arts & recreation | 2019 |
| Totem International Limited | Administrative & support | 2013 |
| Toto Store Limited | Wholesale & retail | 2023 |
| Totp North Limited | Health & social care | 2025 |
| Tots & Teens Limited | Wholesale & retail | 1987 |
| Tottenham Patisserie Limited | Manufacturing | 2025 |
| Totteridge Care Services Limited | Health & social care | 2024 |
| Toucan Create Ltd | Arts & recreation | 2012 |
| Touch Entertainment Production Ltd | Information & communication | 2014 |
| Touch of Class (Commercial) Ltd | Administrative & support | 2013 |
| Touch of Class (Domestic) Ltd | Extraterritorial | 2013 |
| Touche Consulting Limited | Mining & quarrying | 2001 |
| Touchstone Arts Ltd | Information & communication | 2018 |
| Touchwood Cabinet Makers Limited | Manufacturing | 2005 |
| Toughbuilt Industries UK Limited | Manufacturing | 2019 |
| Tour Korea Limited | Transport & logistics | 2010 |
| Tour Line Limited | Administrative & support | 2014 |
| Toureen Contractors Limited | Construction | 1992 |
| Toureen Plant Limited | Construction | 2006 |
| Toureen Trustees Limited | Administrative & support | 2021 |
| Tower Bridge Investments Limited | Manufacturing | 2023 |
| Tower Leasing Sales Limited | Financial services | 2020 |
| Tower Trading Group (EQ) Ltd | Financial services | 2024 |
| Tower Trading Group (GP) Ltd | Financial services | 2024 |
| Tower Trading Group (LP) Ltd | Financial services | 2024 |
| Tower Trading Group Holdings Limited | Financial services | 2022 |
| Towerglade Properties Limited | Professional & scientific | 1998 |
| Towfie Bryle DEE UK Ltd | Health & social care | 2023 |
| Town & Country Shopfitting Limited | Construction | 2003 |
| Towndeals Limited | Wholesale & retail | 2019 |
| Townhall Tyres Ltd | Wholesale & retail | 2026 |
| Townsend Lane Limited | Real estate | 2025 |
| Toytrek Limited | Wholesale & retail | 2025 |
| Toyzone Ltd | Wholesale & retail | 2025 |
| TP Infinity UK Ltd | Information & communication | 2018 |
| TP Infratech Construction Ltd | Construction | 2025 |
| TP Technologies Limited | Information & communication | 2015 |
| TPA Health Limited | Health & social care | 2015 |
| TPCC000 Limited | Real estate | 2015 |
| TPCC002 Limited | Real estate | 2015 |
| TPG Addington House Limited | Construction | 2022 |
| TPG Business Services Ltd | Professional & scientific | 2026 |
| TPG Corporate Holdings Ltd | Financial services | 2026 |
| TPL Clubs Ltd | Arts & recreation | 2024 |
| TPL Tilers-Painting Limited | Construction | 2026 |
| TPM Productions Ltd | Arts & recreation | 2013 |
| TPR Build Ltd | Construction | 2026 |
| TPR Properties Ltd | Real estate | 2021 |
| TPT Payroll Ltd | Professional & scientific | 2012 |
| TPW Surveying Services Ltd | Construction | 2011 |
| TQ Student Property Ltd | Real estate | 2025 |
| TR Pharma Holdings Limited | Financial services | 2024 |
| Tracewick Limited | Wholesale & retail | 1980 |
| Trackcam Ltd | Other services | 2007 |
| Trackcessories Limited | Wholesale & retail | 2025 |
| Tracx Investments LLP | | 2013 |
| Tracxe Limited | Information & communication | 2022 |
| Trade Bond Limited | Real estate | 2015 |
| Trade Creatives Ltd | Education | 2023 |
| Trade Hold Ltd | Construction | 2024 |
| Trade Machine Limited | Manufacturing | 2017 |
| Trade Plastering Ltd | Construction | 2019 |
| Trade Price Autos Ltd | Wholesale & retail | 2023 |
| Trade Route Wholesale Ltd | Wholesale & retail | 2025 |
| Trade Team Consultancy Ltd | Professional & scientific | 2021 |
| Tradecom UK Limited | Wholesale & retail | 2013 |
| Trader Wembley Limited | Real estate | 2021 |
| Tradernometry Ltd | Education | 2025 |
| Tradeworld Healthcare Ltd | Wholesale & retail | 2019 |
| Tradex S.P.R.L Ltd | Wholesale & retail | 2013 |