| Tandem Estate Ltd | Real estate | 2025 |
| Tasman Software Limited | Information & communication | 1998 |
| Taylor Family Investments Limited | Financial services | 2017 |
| Tdmp Eight Limited | Health & social care | 2026 |
| Tdmp Group Limited | Health & social care | 2024 |
| Temple Ford Design Ltd | Professional & scientific | 2010 |
| THE at Home Counsellor Ltd | Health & social care | 2021 |
| THE Birmingham Small Arms Company Limited | Extraterritorial | 2011 |
| THE Corporate Event Company Limited | Arts & recreation | 2002 |
| THE Covent Garden Dance Company Limited | Administrative & support | 2006 |
| THE Duke of Richmond Limited | Hospitality | 2020 |
| THE Landscape Trading Company Limited | Administrative & support | 1996 |
| THE Mathews Collection Limited | Construction | 2026 |
| Thomas Roberts (Westminster) Ltd | Professional & scientific | 1927 |
| Thomas Roberts Estates Limited | Professional & scientific | 1999 |
| Thomas Roberts Limited | Professional & scientific | 1999 |
| Three Oaks Boarding Kennels Limited | Other services | 2023 |
| Tigerfusion Limited | Administrative & support | 2016 |
| Tilbury's (Soton) Limited | Real estate | 1936 |
| Tiny Treasure Town Ltd | Arts & recreation | 2015 |
| Tkls Architecture Ltd | Professional & scientific | 2017 |
| Tolarus Limited | Manufacturing | 2013 |
| TP Btsi Limited | Real estate | 2014 |
| Tragopan Holdings Limited | Administrative & support | 2017 |
| Transnational Engineering Limited | Professional & scientific | 1996 |
| Treasure Gymnastics Club Ltd | Education | 2020 |
| Tripod Estates Limited | Extraterritorial | 2006 |
| True Fitness Technology UK Limited | Wholesale & retail | 2019 |
| True Roots Produce Limited | Wholesale & retail | 2026 |
| TTL Chiltern Property Holdings Limited | Professional & scientific | 2004 |
| Valet Manager Limited | Other services | 2014 |
| Venta Investments Limited | Real estate | 2016 |
| Ventura Hair Design Ltd | Other services | 2011 |
| Vibration Isolation Products Ltd | Wholesale & retail | 2002 |
| Vivid Design Studio Limited | Professional & scientific | 2010 |
| Waihola Limited | Professional & scientific | 2023 |
| Walparite Building Services Limited | Construction | 2002 |
| Webteq Limited | Information & communication | 2005 |
| Wessex Eyes Limited | Health & social care | 2024 |
| Wessex Language Partners Ltd | Professional & scientific | 2003 |
| Wessex Translations Limited | Professional & scientific | 2001 |
| West Link (Romsey) Holdings Limited | Financial services | 2010 |
| Westola Holdings Ltd | Financial services | 2017 |
| Where YOU B-Long Limited | Construction | 2011 |
| Whitecap Associates Limited | Other services | 2011 |
| Whitefox Funding Limited | Financial services | 2016 |
| Whitefox Surveyors Limited | Professional & scientific | 2014 |
| Winchester Garden Machinery Holdings Limited | Financial services | 2015 |
| Winchester Garden Machinery Limited | Wholesale & retail | 1981 |
| Workplace Art Consultancy Limited | Administrative & support | 2005 |
| WS Btsi Limited | Real estate | 2014 |
| XBG Fleet Remarketing Limited | Wholesale & retail | 2003 |
| XBG Limited | Wholesale & retail | 2003 |
| Xora Print Ltd | Manufacturing | 2023 |
| Zenergi Developments Limited | Extraterritorial | 2011 |