| Trxcom Ltd | Financial services | 2013 |
| Tryalero Ltd | Wholesale & retail | 2025 |
| TS Electric Ltd | Construction | 2020 |
| TS Flooring & Carpentry Ltd | Construction | 2025 |
| TS Recruitment Ltd | Administrative & support | 2020 |
| TS Southern Developments Ltd | Administrative & support | 2018 |
| TS7 Group Ltd | Wholesale & retail | 2025 |
| TSC Capital Group Ltd | Professional & scientific | 2024 |
| TSR Consulting Ltd | Professional & scientific | 2025 |
| TT Industries LLP | | 2011 |
| Tube Form Technology Limited | Manufacturing | 2007 |
| Tubnet Ltd | Information & communication | 2021 |
| Tuckers Lane Management Company Ltd | Administrative & support | 2013 |
| Tudor Court (Freehold) Limited | Households | 2016 |
| Tudor Parts Limited | Wholesale & retail | 2015 |
| Tudor Payne & Co. Limited | Professional & scientific | 2009 |
| Tuition Mission Limited | Education | 2023 |
| Tula Yoga Ltd | Arts & recreation | 2017 |
| Tulsi News Limited | Wholesale & retail | 2011 |
| Tunbridge Commercial Investments Limited | Real estate | 1997 |
| Tungsten Consultancy Ltd | Professional & scientific | 2015 |
| TUP Designs Ltd | Wholesale & retail | 2020 |
| Turbary House Management Company Limited | Households | 1983 |
| Turbo Gaming Ltd | Manufacturing | 2021 |
| Turkish Kebab Burgers Bournemouth Ltd | Hospitality | 2025 |
| Turner Street Management Company Limited | Households | 2003 |
| Turnkey Commercial Ltd | Construction | 2026 |
| Turquoise Lake Ltd | Information & communication | 2023 |
| Tutumtravel Ltd | Transport & logistics | 2025 |
| TW Wainwright Consulting Limited | Professional & scientific | 2020 |
| TW14 Ltd | Administrative & support | 2014 |
| Tweedy Limited | Wholesale & retail | 2025 |
| Twellers Ltd | Wholesale & retail | 2020 |
| Twentieth Century Investments Limited | Real estate | 1935 |
| Twenty Clark Street Limited | Professional & scientific | 2023 |
| Twenty Eight Residential Limited | Real estate | 2024 |
| TWENTY20 Distribution Limited | Financial services | 2024 |
| Twentyone Marketing Limited | Professional & scientific | 2016 |
| Twig Training & Consulting Ltd | Information & communication | 2016 |
| Twila’S BBQ & Smokehouse Ltd | Hospitality | 2026 |
| Twinklebug Ltd | Wholesale & retail | 2024 |
| Twins FX Collection Limited | Arts & recreation | 2018 |
| Twins Worldwide Limited | Arts & recreation | 2011 |
| Twinstrans Ltd. | Transport & logistics | 2025 |
| Twist Grip and Spanners Ltd | Wholesale & retail | 2023 |
| Twjc Sprayredering&Plastering Ltd | Construction | 2024 |
| TWK Scaffolding Ltd | Extraterritorial | 2023 |
| TWK Shrinkwrap Ltd | Construction | 2015 |
| Two Blue Hats Ltd | Professional & scientific | 2013 |
| Two Larks Productions Ltd | Information & communication | 2023 |
| Two LR Limited | Households | 2003 |
| Two Putt Limited | Hospitality | 2024 |
| Two Rivers Investments Limited | Health & social care | 2004 |
| Two SIX Recruitment Limited | Administrative & support | 2024 |
| TWR Commercial Flight Training Ltd | Education | 2024 |
| Twynham Management Co Ltd | Real estate | 2017 |
| TX Network Solutions Ltd | Construction | 2026 |
| Tyne Recruitment Venture Partner Ltd | Administrative & support | 2023 |
| Typechoice Limited | Wholesale & retail | 1985 |
| Tyrrell Dowinton Associates (UK) Ltd | Professional & scientific | 2015 |
| Tyrus Zaid Brown Ltd | Extraterritorial | 2023 |
| Tz-Company (UK) Limited | Professional & scientific | 2003 |
| U & CH (LH) Ltd | Real estate | 2012 |
| U - Lease Limited | Financial services | 2004 |
| U-Crew Ltd | Administrative & support | 2022 |
| U-Drive Limited | Administrative & support | 1996 |
| U-Technology Limited | Information & communication | 2025 |
| U4 Developments UK Limited | Other services | 2017 |
| U4 Ltd | Other services | 2018 |
| U4 Park Homes UK Ltd | Other services | 2020 |
| U4 Utilities Limited | Other services | 2016 |
| Ua-Fashed Ltd | Wholesale & retail | 2025 |
| Uab.Global Ltd | Information & communication | 2022 |
| Uavhe Limited | Manufacturing | 2021 |
| Uberbuild Limited | Construction | 2014 |
| Ubertus Manus Ltd | Health & social care | 2021 |
| Uddin Transport Solution Limited | Transport & logistics | 2026 |
| UF Insula Ltd | Wholesale & retail | 2022 |
| UFH Repairs Limited | Construction | 2024 |
| Uhuru Trade Ltd | Wholesale & retail | 2024 |
| Ujjal Malakar AZZ Ltd | Wholesale & retail | 2025 |
| UK Agent X Ltd | Information & communication | 2015 |
| UK Bangla Foods Limited | Wholesale & retail | 2025 |
| UK Bounti Chemical Group Limited | Manufacturing | 2025 |
| UK Business Development Ltd | Wholesale & retail | 2019 |
| UK Diveworks Limited | Arts & recreation | 2015 |
| UK Dropship Ltd | Wholesale & retail | 2025 |
| UK Focus Ltd | Financial services | 2023 |
| UK Heating Matters Limited | Professional & scientific | 2020 |
| UK Manu-Futures Ltd | Professional & scientific | 2026 |
| UK Maritime Services Limited | Transport & logistics | 2016 |
| UK Online Home Sales Ltd | Wholesale & retail | 2020 |
| UK Online Shopping Limited | Wholesale & retail | 2021 |
| UK PAY Ltd | Administrative & support | 2023 |
| UK Perforation Limited | Manufacturing | 2017 |
| UK Phoenix Ltd | Other services | 2019 |
| UK Postbox Limited | Transport & logistics | 2008 |
| UK Resourcing Limited | Administrative & support | 2017 |
| UK Retreats Ltd | Professional & scientific | 2021 |
| UK Sealstone Ltd | Manufacturing | 2026 |