| Total Performance Ltd | Professional & scientific | 2025 |
| Totem Stone Limited | Manufacturing | 2005 |
| Totemic (2014) Holdings Limited | Professional & scientific | 2010 |
| Totemic (2024) Holdings Limited | Professional & scientific | 2024 |
| Totemic 2021 Limited | Extraterritorial | 2021 |
| Totemic Central Services Limited | Administrative & support | 2014 |
| Totemic Inns Limited | Hospitality | 2007 |
| Totemic Limited | Administrative & support | 1993 |
| Totemic Property Limited | Hospitality | 2006 |
| Tourfinders Ltd | Wholesale & retail | 2023 |
| Tower Kiosks Limited | Hospitality | 2014 |
| Towle Consulting Limited | Professional & scientific | 2026 |
| Town Street Capital Limited | Financial services | 2016 |
| Townsend Moore Funeral Services Ltd | Other services | 2014 |
| TQS Advisory Limited | Other services | 2015 |
| Trabern Underwriting LLP | | 2008 |
| Trade Compliant Ltd | Professional & scientific | 2026 |
| Trailbridged Ltd | Wholesale & retail | 2021 |
| Training, Employment, Support Solutions CIC | Other services | 2011 |
| Tranfield Property Limited | Real estate | 2020 |
| Transportconnect Limited | Transport & logistics | 2016 |
| Transunity Ltd | Administrative & support | 2019 |
| Trascent Wipe Ltd | Administrative & support | 2025 |
| Travel B Ltd | Other services | 2022 |
| Treasure Services Group Limited | Financial services | 2016 |
| Treasure Transport Services Ltd | Transport & logistics | 1954 |
| Trent Properties Limited | Real estate | 1986 |
| Trent Valley Kart Club Limited | Arts & recreation | 1995 |
| Trevor Allen Electrical Limited | Construction | 2003 |
| Trew Turner Limited | Construction | 2013 |
| Tribe Leisure Ltd | Wholesale & retail | 2019 |
| Tribex Holdings Limited | Financial services | 2016 |
| Tricia Mclean Ltd | Education | 2019 |
| Trophy Cars Ltd | Wholesale & retail | 2011 |
| Truck and Trailers Parts Ltd | Wholesale & retail | 2025 |
| Truecare Limited | Public administration | 2024 |
| Trust Communications Limited | Information & communication | 2008 |
| Trust Investments Limited | Professional & scientific | 2010 |
| Trustpharm Limited | Health & social care | 2023 |
| Tryac Ltd | Manufacturing | 2021 |
| TSG Plumbing & Heating Limited | Construction | 2018 |
| Tudor Decorators Ltd | Construction | 2019 |
| Tudor House Accountancy Ltd | Professional & scientific | 2021 |
| Turgue Ltd | Administrative & support | 2020 |
| Turners of Bytham LLP | | 2018 |
| Turnor Estates Stoke Rochford Ltd | Financial services | 2024 |
| Turrino Wheels Limited | Wholesale & retail | 2009 |
| Turtlecove Limited | Financial services | 2006 |
| Tuxedo Ltd | Financial services | 2026 |
| Tvcs London Limited | Information & communication | 2018 |
| TWC Real Estate Limited | Real estate | 2016 |
| TWD Properties Limited | Real estate | 2019 |
| Twentytwo Group Limited | Financial services | 2026 |
| Twinic Ltd | Real estate | 2014 |
| Twistriver Ltd | Administrative & support | 2020 |
| Two Four One Limited | Financial services | 1998 |
| Two Wellies Ltd | Hospitality | 2011 |
| TWS (East Midlands) Ltd | Wholesale & retail | 2017 |
| Tymos Technology Limited | Information & communication | 1985 |
| Tyndal Design Limited | Professional & scientific | 2025 |
| Typeright Limited | Education | 2012 |
| Tyre Equipment Co Ltd | Manufacturing | 1987 |
| Tyrez Limited | Manufacturing | 1964 |
| Tythorne Garden Design Limited | Administrative & support | 2020 |
| U.P.I.D Ltd | Construction | 2020 |
| Ubique Property Ltd | Real estate | 2015 |
| Udelivery Limited | Transport & logistics | 2019 |
| UK Cars Dismantlers Ltd | Wholesale & retail | 2022 |
| UK Composite Fencing Ltd | Wholesale & retail | 2025 |
| UK Roof Solutions Limited | Construction | 2014 |
| UK Spray Plaster Ltd | Construction | 2023 |
| UK Stoneworks Limited | Manufacturing | 2025 |
| UK Telecommunications Limited | Information & communication | 2025 |
| UK Tyre Technicians Ltd | Wholesale & retail | 2007 |
| Ukpr Solutions Ltd | Administrative & support | 2024 |
| Uksp Homes Ltd | Real estate | 2025 |
| Ulpian Data Limited | Professional & scientific | 2013 |
| Ultio Ltd | Information & communication | 2015 |
| Umar Shar Ltd | Health & social care | 2022 |
| UNA Patches Ltd | Wholesale & retail | 2020 |
| Uncle Sams Events Limited | Arts & recreation | 2026 |
| Underhill & Associates Limited | Administrative & support | 2003 |
| Underwood Green Limited | Professional & scientific | 2020 |
| Uni-Clean (Midlands) Ltd | Other services | 2023 |
| Uniform Tradings Limited | Wholesale & retail | 2011 |
| Unit G Management Company Ltd | Real estate | 2008 |
| Unpleasant Pheasant Ltd | Information & communication | 2024 |
| UPF Zero Ltd | Manufacturing | 2025 |
| Upgrade Your Company Ltd | Manufacturing | 2024 |
| Upton Writes Limited | Financial services | 2015 |
| Urbanflexwear Limited | Wholesale & retail | 2026 |
| V LUP Civils Ltd | Construction | 2020 |
| V LUP Hire Ltd | Construction | 2026 |
| V Shreeve Limited | Construction | 2007 |
| V.I. Risk Capital LLP | | 2006 |
| Vacu-Lug Industrial Tyres Limited | Manufacturing | 1986 |
| Vacu-Lug Tyres Limited | Manufacturing | 1982 |
| Vaculug Limited | Manufacturing | 1950 |
| Vaculug Technologies Limited | Manufacturing | 1982 |
| Vaderstad Limited | Manufacturing | 1992 |