| TOM Leaper Ltd | Arts & recreation | 2003 |
| Tooshorts Ltd | Wholesale & retail | 2024 |
| Top Food WOK Ltd | Hospitality | 2025 |
| Topflite Landscaping Limited | Administrative & support | 2024 |
| Topiq Limited | Information & communication | 2012 |
| Toppstorr Limited | Wholesale & retail | 2020 |
| Toptechstore Limited | Wholesale & retail | 2023 |
| Torkss Ltd | Health & social care | 2023 |
| Torque Resolutions Limited | Professional & scientific | 2023 |
| Tourdust Limited | Administrative & support | 2009 |
| Tower Museum Bassingbourn | Other services | 1976 |
| Towngate Property Management Limited | Real estate | 2014 |
| Townkey Property Management Limited | Households | 1989 |
| TPB Finance Limited | Professional & scientific | 2019 |
| TPG IT Ltd | Information & communication | 2018 |
| Tpsg Cosmetics Limited | Health & social care | 2025 |
| Tpsg Holdings Limited | Financial services | 2019 |
| TQ Fusion Limited | Professional & scientific | 2014 |
| Trail Tech Limited | Wholesale & retail | 2015 |
| Training Tracker Elearning Ltd | Information & communication | 1997 |
| Tranquility Water Features Limited | Wholesale & retail | 2016 |
| Transmute Wellbeing Ltd | Health & social care | 2016 |
| Trayn Limited | Construction | 2020 |
| Trdbw Limited | Information & communication | 2024 |
| Trecar Property Co Limited | Real estate | 2013 |
| Treeway Limited | | 1972 |
| Tregowan Limited | Households | 2019 |
| Treloyhan (ST. Ives, Cornwall) Estates Limited | Households | 2016 |
| Trelyon Limited | Wholesale & retail | 2007 |
| Tremorna House Property Management Company Limited | Real estate | 2003 |
| Trencrom Limited | Professional & scientific | 2016 |
| Trenithon Apartments Limited | Households | 1988 |
| Treth and MOR Ltd | Wholesale & retail | 2026 |
| Trevenwyth Farm Limited | Construction | 2016 |
| Trevescan Land Limited | Real estate | 2025 |
| Trident (G.M.C.) Limited | Construction | 1979 |
| Trident Architectural Glazing Limited | Construction | 2009 |
| Tridian Software Ltd | Administrative & support | 2003 |
| Truck Style Ltd | Wholesale & retail | 2020 |
| Trumpet Limited | Real estate | 2025 |
| Trustseven Limited | Information & communication | 2017 |
| TSL Property Investment LLP | | 2005 |
| TSM Properties Limited | Real estate | 2024 |
| Tummy Buddies Limited | Wholesale & retail | 2020 |
| Turbine Engineering Consultants Ltd | Professional & scientific | 2010 |
| Tutella Limited | Information & communication | 2015 |
| Tutt & Associates - Consulting Engineers Limited | Professional & scientific | 2025 |
| Tweaks Aesthetics and Beauty Ltd | Other services | 2023 |
| Twenty Twenty Commercial Warranty Ltd | Financial services | 2020 |
| Twenty Twenty Warranty Ltd | Financial services | 2019 |
| Twentydec Accounting Services Ltd | Professional & scientific | 2025 |
| Two Kings Events Limited | Arts & recreation | 2018 |
| Tx-Solutions Ltd | Energy | 2022 |
| U.K.V.S. Holdings Limited | Financial services | 2009 |
| UK Corporate Sports & Events Ltd | Administrative & support | 2019 |
| UK Veneer Systems Limited | Manufacturing | 1996 |
| UK Veneering Limited | Manufacturing | 2006 |
| Unboxing Rituals Limited | Wholesale & retail | 2021 |
| Under Pressure Cambridgeshire Ltd | Administrative & support | 2025 |
| Unified Business IT Limited | Information & communication | 2026 |
| Unified Retail Services Ltd | Information & communication | 2024 |
| Unified Retail UK Ltd | Information & communication | 2014 |
| Uniport Business Systems Limited | Information & communication | 1990 |
| Universal Bliss Ltd | Other services | 2017 |
| Unlimited Software Limited | Information & communication | 2002 |
| UNO Carbis Bay Ltd | Real estate | 2024 |
| UP DE Silva & Co Limited | Other services | 2015 |
| Uplift Property South West Limited | Real estate | 2024 |
| Urbanforte Ltd | Construction | 2025 |
| Vadi Kitchen Limited | Hospitality | 2025 |
| Vale-Tech Limited | Extraterritorial | 2019 |
| Valentine Court Properties Limited | Real estate | 2021 |
| Van Style Ltd | Extraterritorial | 2022 |
| Vawtx Group Ltd | Professional & scientific | 2026 |
| Vehicle Cosmetics Limited | Administrative & support | 2008 |
| Velo Innovations Limited | Manufacturing | 2019 |
| Verdale Limited | Real estate | 2013 |
| Vertex Decorators Ltd | Construction | 2026 |
| Veterinary Waste Services Limited | Professional & scientific | 2007 |
| VIA Alta Limited | Information & communication | 2020 |
| Vibris Limited | Information & communication | 2007 |
| VIC Properties Ltd | Real estate | 2019 |
| Vicky Grant School of Dance Ltd | Education | 2024 |
| Videre Surveying Ltd | Professional & scientific | 2013 |
| Vintix Limited | Wholesale & retail | 2025 |
| Virago Events Ltd | Hospitality | 2021 |
| Visceral Business Limited | Professional & scientific | 2005 |
| Vision Creator Network Ltd | Professional & scientific | 2026 |
| Vltn Digital Ltd | Information & communication | 2018 |
| VWT Power Ltd | Extraterritorial | 2024 |
| VY Enterprise Consultants Ltd | Professional & scientific | 2020 |
| W P Design and Build Limited | Administrative & support | 2017 |
| W.D. Cade Limited | Construction | 1978 |
| W.R.K Real Estate Ltd | Real estate | 2026 |
| Walters Way Management Company Limited | Real estate | 2020 |
| Wams Advisors Limited | Education | 2025 |
| WAP Partnership Ltd | Wholesale & retail | 2015 |
| Warranty My Holdings Ltd | Financial services | 2026 |
| Waterfront Developments (Braintree) Limited | Construction | 2015 |
| Waterway Hair & Beauty Limited | Other services | 2020 |