| Townsend Bowen Limited | Professional & scientific | 2004 |
| Townsend Driver Services Limited | Transport & logistics | 2015 |
| Towsey Plumbing and Heating Ltd | Construction | 2026 |
| Toyotech Limited | Wholesale & retail | 2016 |
| TP Lifestyle Ltd | Administrative & support | 2020 |
| TP Transport Limited | Education | 2023 |
| TP2 Care Service Limited | Health & social care | 2025 |
| TP2 Limited | Information & communication | 2017 |
| TPH Property Ltd | Real estate | 2024 |
| TPS Interiors Limited | Professional & scientific | 2010 |
| Tpvh Limited | Administrative & support | 2024 |
| TR Property (2017) Ltd | Real estate | 2017 |
| Trac Contracts Ltd | Administrative & support | 2025 |
| Trace Property Solutions Limited | Real estate | 2024 |
| Track Thunder Ltd | Wholesale & retail | 2023 |
| Trade Link Interiors Ltd | Construction | 2009 |
| Trade Mark Support Services Limited | Professional & scientific | 2004 |
| Tradesbook Ltd | Information & communication | 2014 |
| Traditional Treats Ltd | Wholesale & retail | 2018 |
| Traditional Turkish Barber 1 Ltd | Other services | 2019 |
| Trafalgar Court (Brightlingsea) Company Limited | Households | 2005 |
| Traiteur Properties (KT) Limited | Real estate | 2003 |
| Transactiq Consultancy Limited | Administrative & support | 2025 |
| Transfer Associates Limited | Administrative & support | 2018 |
| Transfer Pricing Associates Limited | Professional & scientific | 2004 |
| Transfer Pricing Professionals LLP | | 2009 |
| Transfidelis Limited | Professional & scientific | 2016 |
| Transforming Exercise and Nutrition Ltd | Other services | 2019 |
| Transglobal Distribution Limited | Wholesale & retail | 2014 |
| Transit Trader Limited | Wholesale & retail | 2017 |
| Translatormag Holdings Ltd | Information & communication | 2024 |
| Translatormag Limited | Information & communication | 2026 |
| Transport Solution 4U Ltd | Transport & logistics | 2021 |
| Tranters Cleaning & Maintenance Ltd | Administrative & support | 2023 |
| Travel Services Ltd | Administrative & support | 2007 |
| Traverse Advisory Limited | Administrative & support | 2011 |
| Treasure Trove Luxe Ltd | Wholesale & retail | 2025 |
| Tredzone Ltd | Wholesale & retail | 2019 |
| Tree & Lawn Company Limited | Administrative & support | 2011 |
| Tree of Life Ministry Limited | Health & social care | 2025 |
| Tree Pros Essex Ltd | Administrative & support | 2019 |
| Treemendous Oaks Ltd | Agriculture & fishing | 2024 |
| Treetops Court Management Company Limited | Hospitality | 2007 |
| Treharne Accounting Limited | Professional & scientific | 2019 |
| Trelawn LLP | | 2012 |
| Tremain Management Company Limited | Real estate | 1999 |
| Tremelaia Gardens (Management Company) Limited | Real estate | 2012 |
| Trends Consult Limited | Education | 2025 |
| Trends in TEX Textile Sourcing Ltd | Wholesale & retail | 2026 |
| Trendwave Trading Limited | Professional & scientific | 2017 |
| Trendzapps Ltd | Information & communication | 2025 |
| Trennd Ltd | Wholesale & retail | 2024 |
| Trent House (Ipswich) Limited | Real estate | 1998 |
| Trent House (Residential) Limited | Real estate | 1999 |
| Trentacapille Services Ltd | Construction | 2024 |
| Trevco Limited | Wholesale & retail | 2014 |
| Trevester Limited | Financial services | 2008 |
| Trevor Cobbold Limited | Extraterritorial | 2010 |
| Trexima Limited | Professional & scientific | 1987 |
| Trgopromet Ltd | Information & communication | 2025 |
| Tri-Mac Consulting Limited | Financial services | 2014 |
| Tria House Limited | Professional & scientific | 2026 |
| Tribelet Ltd | Wholesale & retail | 2025 |
| Tridea UK Ltd | Wholesale & retail | 2017 |
| Trident Oceanic Solutions Limited | Professional & scientific | 2025 |
| Trigglypuffs Investments Limited | Financial services | 2026 |
| Trilogy Supplies Ltd | Wholesale & retail | 2026 |
| Trimmers Hair Limited | Administrative & support | 2012 |
| Trinity Electrics Limited | Construction | 2014 |
| Trinity Executive Search Limited | Administrative & support | 2025 |
| Trinity Global Services Limited | Real estate | 2023 |
| Trinity Handyman & Electrical Ltd | Construction | 2020 |
| Trinity House Estates Limited | Real estate | 2009 |
| Trinity House Trading Limited | Construction | 2009 |
| Trinity Impact Global Consult Ltd | Administrative & support | 2026 |
| Trinity Patisserie Limited | Manufacturing | 2024 |
| Trioblancos Limited | Real estate | 2017 |
| Triple M Healthcare Ventures Limited | Health & social care | 2017 |
| Triskelion Games Limited | Manufacturing | 2021 |
| Triskelion Pictures Limited | Information & communication | 2023 |
| Tritons Gym Ltd | Arts & recreation | 2023 |
| Triumph B2B Ltd | Professional & scientific | 2023 |
| Triumph Golf Ltd | Wholesale & retail | 2025 |
| Trivera Brokers Limited | Financial services | 2025 |
| Troika Books Ltd | Information & communication | 2012 |
| Trollope Ltd | Professional & scientific | 2024 |
| Trotman Property Evolution Ltd | Construction | 2020 |
| Troutstalker Limited | Administrative & support | 2017 |
| Trucare Wellness Ltd | Health & social care | 2025 |
| Trucker G Transport Ltd | Transport & logistics | 2025 |
| True Holdings Limited | Financial services | 2019 |
| True Living Limited | Real estate | 2019 |
| True Nest Prime Properties Limited | Real estate | 2026 |
| True Property Developments Limited | Construction | 2019 |
| Truhair Clinic Ltd | Other services | 2025 |
| Truman Building (Colchester) RTM Company Limited | Households | 2015 |
| Trust Digital Limited | Professional & scientific | 2019 |
| Trust Mortgage Solutions Ltd | Financial services | 2017 |
| Trusted Advisory Services Ltd | Professional & scientific | 2017 |
| Trusted Money Confidence Ltd | Health & social care | 2023 |