| THE Tatton Park Charitable Trust | Arts & recreation | 2005 |
| THE Tawe Management Company Ltd | Real estate | 2023 |
| THE Wide Plank Co. UK Ltd | Professional & scientific | 2005 |
| THE Wild Bunch (Macc) Limited | Wholesale & retail | 2003 |
| THE Winning Way Limited | Education | 2005 |
| THE Wireless Network Ltd | Information & communication | 1997 |
| THE World Federation of Rose Societies | Education | 1997 |
| Thermal Glazing Installations Limited | Construction | 1994 |
| Thermo Fisher Scientific Life International Holdings II LP | | 2021 |
| Thermo Fisher Scientific Life UK Holdings 2 LP | | 2023 |
| Thermo Fisher Scientific Life UK Holdings LP | | 2022 |
| Therstore Ltd | Wholesale & retail | 2015 |
| Thirteen Kensington Road Wakefield Limited | Real estate | 1990 |
| This Planet Earth Limited | Manufacturing | 1989 |
| Thompson Sheet Metal Limited | | 1975 |
| Thompsons of Macclesfield Limited | Wholesale & retail | 1964 |
| Threadfast Engineers (1984) Limited | Wholesale & retail | 1984 |
| Thrive (Cheshire) Ltd | Manufacturing | 2006 |
| Tibard Holdings Limited | Professional & scientific | 2005 |
| TIM Worthington Limited | Construction | 2007 |
| Time & Leisure Limited | Real estate | 1995 |
| Timothy Guttridge Limited | Administrative & support | 2000 |
| Tirawa Consulting Ltd | Information & communication | 2025 |
| TKN Solicitors Limited | Professional & scientific | 2020 |
| TL and Co (UK) Ltd | Manufacturing | 2014 |
| TOL Events Ltd | Administrative & support | 2003 |
| Tomlinson Management Holdings Limited | Professional & scientific | 2011 |
| Tong Building and Joinery Limited | Construction | 2005 |
| Tonik Holdings Limited | Administrative & support | 1999 |
| Torbay Staff Agency Limited | Administrative & support | 2020 |
| Total Jetting Services Ltd. | Administrative & support | 1997 |
| Total Property Servicing Limited | Construction | 2007 |
| Total Rugby Limited | Extraterritorial | 1991 |
| Totally Trad Signs Limited | Professional & scientific | 2006 |
| Touchalert Limited | Manufacturing | 1993 |
| Town Bridge Motors Limited | Wholesale & retail | 2004 |
| Townshow Limited | | 1987 |
| Trabo Limited | Wholesale & retail | 2005 |
| Trackline Music Services | | 1988 |
| Tracksharp Limited | | 1983 |
| Trade Units Limited | Professional & scientific | 2007 |
| Trade Window Supplies Limited | Construction | 2008 |
| Trainability U.K. Limited | Professional & scientific | 1992 |
| Training Dimensions Limited | Education | 2002 |
| Trans-Global Commerce Limited | Extraterritorial | 1991 |
| Transmission (Hoses) Limited | Wholesale & retail | 1969 |
| Trapstreet Limited | Professional & scientific | 2008 |
| Traust Bidco Limited | Financial services | 2021 |
| Traust Midco 1 Limited | Financial services | 2021 |
| Traust Midco 2 Limited | Financial services | 2021 |
| Traust Topco Limited | Financial services | 2021 |
| Traveloptions Sport Ltd | Administrative & support | 2020 |
| Traycar Systems Limited | Manufacturing | 1999 |
| Treasbeare Residential Limited | Construction | 2020 |
| Treat Your Lawns Ltd | Administrative & support | 2005 |
| Treegate Ltd | Real estate | 2004 |
| Treetops Education Centers Ltd | Education | 2025 |
| Tregenna Limited | Wholesale & retail | 2007 |
| Trentford Designs Limited | Administrative & support | 1996 |
| Trilite Projects Limited | Construction | 1998 |
| Trinity Court Henshall Hall Management Company Limited | Households | 1981 |
| Triple a Lift Refurbishment (N.W.) Limited | Construction | 1990 |
| Triple S Group Properties Limited | Real estate | 2025 |
| Trls Care Limited | Health & social care | 2022 |
| Trolex Limited | Manufacturing | 1959 |
| Tronicvogue Limited | | 1984 |
| Truck & Trailer Spares (NW) Limited | Wholesale & retail | 2008 |
| True Vine Limited | Other services | 2006 |
| Tsiantar Architects Limited | Professional & scientific | 2003 |
| Tuscany Restaurants Limited | Hospitality | 1983 |
| Tussies Limited | Professional & scientific | 1996 |
| TWH Projects Limited | Professional & scientific | 2002 |
| Twinbuy Limited | Professional & scientific | 1989 |
| TY LON Cottages Management Company Limited | Real estate | 2006 |
| Tylmail.Com Limited | Administrative & support | 2006 |
| U.K. Control Systems Ltd | Construction | 1997 |
| U.K. Handrails Ltd | Construction | 2020 |
| UK Biobank Limited | Professional & scientific | 2003 |
| UK Emergency Medical Transport Ambulance Service Limited | Health & social care | 2020 |
| UK Landscapes Holdings Limited | Financial services | 2021 |
| Ukubid.Com Ltd. | Professional & scientific | 2007 |
| Ultima Newco 1 Limited | Financial services | 2025 |
| Ultima Newco 2 Limited | Financial services | 2025 |
| Ultimex Limited | Information & communication | 1995 |
| Ultium Business Outsourcing Group Limited | Extraterritorial | 2016 |
| Unearthed Gardens Limited | Administrative & support | 2020 |
| Unicorns and Black Swans Ltd | Professional & scientific | 2020 |
| Union Manchester (East and West) Management Limited | Real estate | 2021 |
| Unique Consulting Solutions Ltd | Professional & scientific | 2001 |
| Universal Solutions 4 Business Limited | Information & communication | 1999 |
| Untapped Potential Recruitment Limited | Administrative & support | 2018 |
| Unwins of Heaton Moor Limited | Wholesale & retail | 2003 |
| UR Executive Private Hire Limited | Transport & logistics | 2007 |
| Urban & City Holdings Limited | Construction | 2006 |
| Urenco Nuclear Stewardship Limited | Manufacturing | 2000 |
| Urmston Service Station Limited | Wholesale & retail | 1995 |
| UVB Holdings Limited | Financial services | 2025 |
| V K Super Store Ltd | Wholesale & retail | 2026 |
| V.B. Fabrications Limited | Manufacturing | 2002 |
| Vacancy Response Limited | Administrative & support | 1995 |