| Trigger Capital Ltd | Professional & scientific | 2020 |
| Triggerfish Contracts Ltd | Wholesale & retail | 2012 |
| Trimble Project Management Services Ltd | Professional & scientific | 2015 |
| Tring Specsavers Limited | Wholesale & retail | 2002 |
| Trinity Mews (Torquay) Management Company Limited | Real estate | 2006 |
| Trinity Property Holdco Limited | Financial services | 2024 |
| Trinity Property Propco Limited | Financial services | 2024 |
| Trinsic (Group) Limited | Professional & scientific | 2022 |
| Trinsic Limited | Information & communication | 2013 |
| TRJ Limited | Wholesale & retail | 2019 |
| TRM Heritage Limited | Financial services | 2017 |
| Trojan Mailing Ltd | Manufacturing | 2010 |
| Tropical IT Solutions Ltd | Information & communication | 2019 |
| Trowbridge Specsavers Limited | Wholesale & retail | 1993 |
| Trowbridge Visionplus Limited | Wholesale & retail | 1993 |
| True Support Limited | Administrative & support | 2023 |
| Truffle & Snout Company Ltd | Manufacturing | 2022 |
| Truffles Fareham Ltd | Real estate | 2023 |
| Truro Domi Audiology Specsavers Limited | Wholesale & retail | 2024 |
| Truro Specsavers Hearcare Limited | Wholesale & retail | 2006 |
| Truro Specsavers Limited | Wholesale & retail | 1988 |
| Truro Visionplus Limited | Wholesale & retail | 2000 |
| Trustees of the Southsea Deckchairs EOT Limited | Extraterritorial | 2024 |
| Trych Property Ltd | Real estate | 2025 |
| TS Tyre Repairs Limited | Wholesale & retail | 2004 |
| TTB Property Management Ltd | Households | 2021 |
| TTM Sports Media Ltd | Education | 2023 |
| TTP Enterprises Limited | Arts & recreation | 2014 |
| Tuco Developments Limited | Manufacturing | 2003 |
| Tugnet Digital Ltd | Information & communication | 2021 |
| Tuile Housing Ltd | Professional & scientific | 2025 |
| Tunbridge Wells Specsavers Hearcare Limited | Wholesale & retail | 2014 |
| Tunstall Specsavers Limited | Wholesale & retail | 2014 |
| Turbocam UK Limited | Manufacturing | 1999 |
| TURBOMECA322 Limited | Professional & scientific | 1965 |
| Turner Building Contractors Hampshire Limited | Construction | 2026 |
| Turneround Limited | Administrative & support | 1998 |
| Turnpike Plumbing and Heating Limited | Construction | 1985 |
| Tuteevo Limited | Education | 2025 |
| Tuts Grill Limited | Hospitality | 2024 |
| Tutton Properties Ltd | Real estate | 2021 |
| TUV SUD (UK) Limited | Professional & scientific | 1996 |
| TUV SUD Babt Unlimited | Professional & scientific | 1982 |
| TUV SUD Services (UK) Limited | Administrative & support | 1956 |
| TUX & Co Estates Limited | Real estate | 2025 |
| Tweed Ltd | Administrative & support | 2024 |
| Twenty One Solutions Ltd | Information & communication | 2017 |
| TWENTY3 - Investments Group Ltd | Real estate | 2023 |
| Twentytwo Recruitment Limited | Administrative & support | 2022 |
| Twickenham Specsavers Limited | Wholesale & retail | 2008 |
| Twickenham Visionplus Limited | Wholesale & retail | 2008 |
| Twin Developments Ltd | Construction | 2022 |
| Twinseas Boats Limited | Manufacturing | 2013 |
| Twinstar Maritime Ltd | Professional & scientific | 2024 |
| Two CR Filton (CH) Limited | Construction | 2021 |
| Two Oceans Strategy Limited | Professional & scientific | 2019 |
| TWS Watches Ltd | Wholesale & retail | 2024 |
| Twyford Property Investment Management Limited | Real estate | 2004 |
| Typethree Ltd | Other services | 2025 |
| Tyto Ecology Ltd | Professional & scientific | 2024 |
| Tzani Translations Limited | Professional & scientific | 2003 |
| U Malik Spice Ltd | Hospitality | 2025 |
| U037 Design Limited | Professional & scientific | 2016 |
| Uckfield Specsavers Hearcare Limited | Wholesale & retail | 2025 |
| Uckfield Specsavers Limited | Wholesale & retail | 2003 |
| UHN LLP | | 2024 |
| UK Custom Covers Limited | Wholesale & retail | 2006 |
| UK Land Consultancy Limited | Real estate | 2022 |
| UK Metal Recycling Southampton Ltd | Wholesale & retail | 2026 |
| UK Modern Living Developments, L.P. | | 2021 |
| UK Packaging Solutions Ltd | Other services | 2017 |
| UK Partners Against Crime Limited | Other services | 2016 |
| UK Plumbing Contractors Limited | Construction | 2013 |
| UK Property Relocation Ltd | Hospitality | 2023 |
| UK Recycle Group Ltd | Water & waste | 2021 |
| UK Talent EDU Ltd | Education | 2024 |
| UK Vape Carts Limited | Wholesale & retail | 2024 |
| UK Wholesale Ltd | Wholesale & retail | 2013 |
| Ukawi Ltd | Households | 2019 |
| Ukza Solutions Ltd | Professional & scientific | 2004 |
| UL Holdco 2 Limited | Other services | 2024 |
| UL Holdco Limited | Financial services | 2024 |
| UL Propco 1 Limited | Financial services | 2024 |
| UL Propco 2 Limited | Financial services | 2024 |
| UL Propco 3 Limited | Financial services | 2024 |
| UL Propco 4 Limited | Financial services | 2025 |
| UL Propco 5 Limited | Financial services | 2025 |
| UL Propco Rainham Limited | Financial services | 2025 |
| Uncover Analytics Limited | Information & communication | 2014 |
| Under the Ropes Ltd | Professional & scientific | 2025 |
| Understanding Therapy Ltd | Health & social care | 2023 |
| Uneek by Nature Limited | Other services | 2021 |
| Unhinged Productions Limited | Information & communication | 2018 |
| Uniestate Properties UK Ltd | Real estate | 2025 |
| Unified Consultancy Limited | Wholesale & retail | 2010 |
| Union Mart Limited | Wholesale & retail | 2013 |
| Unipilot Education Technology Group Ltd | Information & communication | 2026 |
| Uniqpupco. Ltd | Wholesale & retail | 2025 |
| Unique Student Living Limited | Real estate | 2017 |
| Unispectra Ltd | Administrative & support | 2011 |