| Top Marks London Ltd | Construction | 2014 |
| Top Minerals Trading Co., Limited | Manufacturing | 2023 |
| Top Petrochemical International Co., Ltd. | Extraterritorial | 2018 |
| Top Procargo Co., Ltd. | Professional & scientific | 2014 |
| Top-Win A&P Trading Co., Ltd | Extraterritorial | 2021 |
| Topa Industry Co., Ltd | Extraterritorial | 2013 |
| Topchina Industry Ltd | Extraterritorial | 2012 |
| Topfar Ltd | Extraterritorial | 2023 |
| Tophydra Trading Co., Ltd | Wholesale & retail | 2021 |
| Topiary Garden Ltd | Wholesale & retail | 2024 |
| Toplife Electronic Technology Limited | Extraterritorial | 2020 |
| Topnuo Group Co., Ltd | Extraterritorial | 2023 |
| Topone Technology Co., Ltd | Extraterritorial | 2020 |
| Topower Limited | Wholesale & retail | 2024 |
| Toproi Limited | Wholesale & retail | 2025 |
| Topsen Int'L Group Ltd | Extraterritorial | 2014 |
| Topshots Digiart Ltd | Extraterritorial | 2021 |
| Topson (UK) Electrical Equipment Co., Ltd | Extraterritorial | 2021 |
| Topstar Trading Limited | Manufacturing | 2023 |
| Toptek Mechatronics Co., Ltd | Extraterritorial | 2015 |
| Topway Import and Export Corporation Ltd. | Professional & scientific | 2015 |
| Torbo Fourseas Marine Service Co., Ltd | Extraterritorial | 2020 |
| Tosamco Limited | Construction | 2018 |
| Tosanta Limited | Construction | 2002 |
| Tosei Supply Chain Co., Ltd. | Extraterritorial | 2024 |
| TOT Building Materials Co. Ltd | Manufacturing | 2023 |
| Total Care Insight Limited | Professional & scientific | 2018 |
| Total Homes (Midlands) Limited | Real estate | 2019 |
| Total Industry Co., Ltd | Wholesale & retail | 2024 |
| Total Laundry Care Services Limited | Other services | 2004 |
| Total Mountain Limited | Hospitality | 2014 |
| Toto Outside Catering Ltd | Hospitality | 2025 |
| Touch Social Ltd | Professional & scientific | 2025 |
| TOUCH2FINISH Services Ltd | Transport & logistics | 2026 |
| Touchdown Pictures Limited | Professional & scientific | 2018 |
| Touchstone Safety Limited | Professional & scientific | 2016 |
| Tourway Auto Co., Ltd. | Manufacturing | 2024 |
| Tower Hardware Trading Co., Ltd | Wholesale & retail | 2021 |
| Townhome Developments Ltd | Construction | 2025 |
| Townlawns Property Management Limited | Households | 1991 |
| Toy Technology Ltd | Wholesale & retail | 2021 |
| Toyar Industrial Ltd | Wholesale & retail | 2018 |
| Toysclub Co., Ltd. | Extraterritorial | 2022 |
| TP Decor Co., Ltd | Manufacturing | 2021 |
| Tpaus Industrial Co., Ltd | Extraterritorial | 2021 |
| Trackent Limited | Health & social care | 2013 |
| Traction Rail Electrical Limited | Construction | 2013 |
| Trade Window Store Ltd | Wholesale & retail | 2023 |
| Tradeaider UK Limited | Wholesale & retail | 2021 |
| Tradeshaw Limited | Wholesale & retail | 2018 |
| Trading Bear Ltd | Professional & scientific | 2013 |
| Trail-Blazer Manufacturing Co., Ltd | Wholesale & retail | 2020 |
| Transcen Trading Co., Ltd | Manufacturing | 2023 |
| Transco 69 Ltd | Transport & logistics | 2018 |
| Transitions Career Management and Training Ltd | Professional & scientific | 2012 |
| Translate Worldwide Ltd | Extraterritorial | 2012 |
| Transtern Group Ltd | Manufacturing | 2024 |
| Transton Automobile Technology Co., Ltd | Manufacturing | 2023 |
| Traud (UK) Ltd | Extraterritorial | 2021 |
| Travel Insurance Consulting Limited | Financial services | 2008 |
| Travelite Limited | Information & communication | 2020 |
| Travelsite Limited | Real estate | 2003 |
| Travity(Uk)Life Science Co., Ltd | Wholesale & retail | 2025 |
| TRD Group Co., Ltd | Extraterritorial | 2018 |
| Tread-Well Surfacing Solutions Ltd | Construction | 2025 |
| Treasure Chest Investments Ltd | Administrative & support | 2020 |
| Treasure Publishing Limited | Information & communication | 2006 |
| Treerangers Limited | Agriculture & fishing | 2013 |
| Treetend Ltd | Extraterritorial | 2008 |
| Trendy Sage Company Limited | Wholesale & retail | 2025 |
| Trez Beauty Limited | Other services | 2012 |
| TRI Proteco Materials Co., Ltd | Professional & scientific | 2021 |
| TRI Union Supply Chain Limited | Wholesale & retail | 2019 |
| Tri-Lithographics Ltd. | Manufacturing | 1988 |
| Trialink Co., Ltd | Extraterritorial | 2020 |
| Triangle Int'L Enterprise Co., Ltd | Professional & scientific | 2016 |
| Trianz Digital Ltd | Information & communication | 2020 |
| Trianz Digital Solutions Limited | Information & communication | 2020 |
| Trianz Limited | Information & communication | 2016 |
| Trinity Coterie Ltd | Real estate | 2017 |
| Trion Industrial Limited | Extraterritorial | 2010 |
| Tripcon Consulting Limited | Professional & scientific | 2012 |
| Tristar Underwriting Ltd | Financial services | 2008 |
| Tristop Media Ltd | Professional & scientific | 2018 |
| Tritseco Limited | Manufacturing | 2022 |
| Triumph Consultants Group Limited | Professional & scientific | 2010 |
| Triumph Consultants Limited | Administrative & support | 2000 |
| Triumph Office Limited | Administrative & support | 2010 |
| Trodd Consultants Limited | Information & communication | 2025 |
| Tropical Grill Ltd | Extraterritorial | 2019 |
| Troy Taxis Limited | Transport & logistics | 2009 |
| True Ally Care Services Ltd | Health & social care | 2025 |
| True Health Collective Ltd | Wholesale & retail | 2022 |
| Truelove TV Limited | Information & communication | 2024 |
| Truemark IP Ltd | Extraterritorial | 2025 |
| Trumy Industrial Co., Ltd | Extraterritorial | 2016 |
| Trung HA Building Materials Co., Ltd | Mining & quarrying | 2022 |
| Truro Property Development Limited | Construction | 2020 |
| Trustar Group Limited | Manufacturing | 2026 |
| Truvo Ltd. | Extraterritorial | 2025 |