| Taleos Consulting Limited | Information & communication | 2014 |
| Tampo Supplies Limited | Manufacturing | 1999 |
| Tandee Limited | Professional & scientific | 2012 |
| Tardis Catering Ltd | Hospitality | 2018 |
| Target Professionals Limited | Information & communication | 2019 |
| TAU Fell Limited | Professional & scientific | 2011 |
| Tauro Limited | Households | 2015 |
| Tax LEX London Limited | Professional & scientific | 2011 |
| Tax LEX Ltd | Professional & scientific | 2023 |
| TBT Construction & Engineering Limited | Construction | 2021 |
| TCG BUI Ltd | Wholesale & retail | 2026 |
| TCL Air Conditioning Ltd | Construction | 2005 |
| TCL Air Conditioning Trustee Limited | Professional & scientific | 2022 |
| Tctv Ltd | Information & communication | 2021 |
| Techmar-Uk Ltd | Wholesale & retail | 2026 |
| Technovision UK Ltd | Information & communication | 1974 |
| Techsupportuk Ltd | Information & communication | 2023 |
| Telestell Limited | Professional & scientific | 2013 |
| Terra Forge Limited | Construction | 2024 |
| Terracloud Limited | Information & communication | 2022 |
| Terradev Ltd | Information & communication | 2004 |
| Teshno Investments Ltd | Construction | 2020 |
| Tessellytics Ltd | Professional & scientific | 2020 |
| Thames Court Limited | Real estate | 2010 |
| Thames Heating Services Ltd | Construction | 2016 |
| Thames West Bathrooms Limited | Construction | 2009 |
| Thameside Podiatry Ltd | Health & social care | 2026 |
| THE Art Printorium Ltd | Wholesale & retail | 2012 |
| THE Collagen Corporation Ltd | Manufacturing | 2022 |
| THE Content Carpenter Limited | Professional & scientific | 2020 |
| THE Cupcake Chef Ltd | Hospitality | 2021 |
| THE Drape Company Ltd | Information & communication | 2015 |
| THE Early Years Consortium Ltd | Education | 2016 |
| THE Expert Car Finder Limited | Other services | 2015 |
| THE Film Game International Ltd | Wholesale & retail | 2025 |
| THE Grange (Stanwell) Management Limited | Households | 2007 |
| THE Green&Blue Screen Company Limited | Information & communication | 2013 |
| THE Hoseman Ltd | Manufacturing | 2020 |
| THE Inclusion Edit Ltd | Professional & scientific | 2025 |
| THE Kitchenologists Ltd. | Wholesale & retail | 2013 |
| THE Kohli Group Ltd | Transport & logistics | 2025 |
| THE Last DOT Ltd | Wholesale & retail | 2024 |
| THE Leadership Partnership Ltd | Education | 2026 |
| THE London Head and Neck Clinic Ltd | Health & social care | 2015 |
| THE Market Steps Ltd | Information & communication | 2025 |
| THE Nineties Ltd | Professional & scientific | 2023 |
| THE Nurture Nest Early Intervention Centre Ltd | Education | 2024 |
| THE Resolution Engine Ltd | Professional & scientific | 2024 |
| THE Sustainable Fashion Collective Limited | Information & communication | 2019 |
| THE Travel Acquisition Company Limited | Hospitality | 2004 |
| THE Trinket Store Limited | Wholesale & retail | 2025 |
| THE Well Heeled Coach Ltd | Administrative & support | 2020 |
| THE Wilsons Family Limited | Professional & scientific | 2020 |
| Their Future Today | Extraterritorial | 2015 |
| Thelongford Ltd | Construction | 2017 |
| Thesweetspotlondon Ltd | Wholesale & retail | 2025 |
| Think New Ltd | Other services | 2021 |
| Thinkclock Ltd | Manufacturing | 2019 |
| Thornfield Digital Ltd | Professional & scientific | 2020 |
| THREE3ONE Ltd | Construction | 2018 |
| Tier 1 Consultants Limited | Administrative & support | 2011 |
| Tilelli Management Consultancy Limited | Professional & scientific | 2017 |
| TIM Evans Consulting Limited | Financial services | 2003 |
| Time Line Productions (UK) Ltd | Information & communication | 2002 |
| Timeless Analytics Limited | Information & communication | 2018 |
| Timeless IT Business Ltd | Information & communication | 2010 |
| Timeless Techfriend Limited | Information & communication | 2016 |
| Titan Force Limited | Transport & logistics | 2026 |
| Tivisha Ltd | Real estate | 2024 |
| TLC Professionals Limited | Administrative & support | 2021 |
| TLF Consulting Limited | Professional & scientific | 2021 |
| TMJ 1 Lettings Limited | Real estate | 2025 |
| TMJ 2 Lettings Limited | Real estate | 2025 |
| TNJ Pankhania Ltd | Real estate | 2021 |
| Tnk’S Detailing Ltd | Administrative & support | 2021 |
| Todid Ltd | Professional & scientific | 2019 |
| Top MOB Gadgets Ltd | Other services | 2023 |
| Top Tier Chimney Sweeps Ltd | Other services | 2025 |
| Toppings Contructions Limited | Construction | 2025 |
| Tough Surveys Limited | Professional & scientific | 2006 |
| TR Building Contractors Ltd | Construction | 2018 |
| Trade City Sunbury Management Company Limited | Real estate | 2013 |
| Trading Worldwide Ltd | Construction | 2019 |
| Trans Darek Ltd | Manufacturing | 2025 |
| Treklers Ltd | Transport & logistics | 2013 |
| Triguna Ventures Limited | Hospitality | 2024 |
| Truckmend London Limited | Manufacturing | 2014 |
| Truehome Construction Ltd | Real estate | 2022 |
| Trusol Limited | Information & communication | 2002 |
| Trustworks Education Ltd | Education | 2025 |
| TSR Homes Limited | Real estate | 2020 |
| Tudor Court Residents Association (Rickmansworth) Limited | Households | 1974 |
| Tuesday Egham Netball Limited | Arts & recreation | 2023 |
| Turning Circle Solutions Limited | Professional & scientific | 2001 |
| TW & WA Chadwick Ltd | Other services | 2001 |
| TW16 Ltd | Real estate | 2016 |
| Tyco Building Services Products (UK) Limited | Wholesale & retail | 1990 |
| Tyco Fire Products Manufacturing Limited | Wholesale & retail | 1984 |
| Tyco Holdings (U.K.) Limited | Professional & scientific | 1990 |
| Tyre Trade (London) Ltd | Wholesale & retail | 2018 |