| Tlc.Expert Ltd | Professional & scientific | 2018 |
| TLS (Peckham Road) Ltd | Construction | 2014 |
| TMA Productions Ltd | Administrative & support | 2025 |
| TNJ Associates Limited | Information & communication | 2017 |
| TNJ Management Limited | Real estate | 2021 |
| TNJ Properties and Management Limited | Real estate | 2022 |
| TNT Consultants Limited | Administrative & support | 2016 |
| Tobacco Trading International Limited | Manufacturing | 1993 |
| Tofan Group Limited | Construction | 2015 |
| Tofos Limited | Information & communication | 2001 |
| TOH Trading Limited | Administrative & support | 2006 |
| Toko Interim Management Ltd | Professional & scientific | 2011 |
| Tonini Bitlab Ltd | Wholesale & retail | 2024 |
| Tonini Finance Limited | Professional & scientific | 2015 |
| Tontilly Limited | Real estate | 2022 |
| Top Financial Services Ltd | Financial services | 2022 |
| Top Fruit&Veg Limited | Wholesale & retail | 2025 |
| Top GEM Limited | Other services | 1980 |
| Topaz Letting and Property Management Limited | Real estate | 2017 |
| Topgrade Properties Limited | Construction | 1993 |
| Topps Maintenance Services Limited | Construction | 2024 |
| TOR Enterprises Limited | Professional & scientific | 2021 |
| Toro Markets Limited | Financial services | 2025 |
| Tosca Investments Limited | Professional & scientific | 2009 |
| Total Commodities Limited | Water & waste | 2007 |
| Total Prosperity Ltd | Real estate | 2021 |
| Total Shred Limited | Water & waste | 2007 |
| Total Truth Limited | Agriculture & fishing | 2015 |
| Totally Lifestyle Ltd | Households | 2019 |
| Totallyplant.Com Limited | Manufacturing | 2009 |
| Toto Ndogo Ltd | Education | 2020 |
| Tots and Scholars Limited | Health & social care | 2015 |
| Tottenham Lane Limited | Real estate | 2019 |
| Tottoro Ltd | Construction | 2024 |
| Tower Estates (UK) Limited | Real estate | 2006 |
| Townsend Financial Services Limited | Professional & scientific | 2024 |
| TPS Abbeydale Archway Limited | Real estate | 2016 |
| TPS Abbeydale Developments Limited | Real estate | 2015 |
| TPS Abbeydale Oaklands Limited | Real estate | 2015 |
| TPS Abbeydale ST Albans Limited | Real estate | 2017 |
| TPS Management Services Limited | Real estate | 2013 |
| Tpsa Archway Limited | Real estate | 2022 |
| Tpsy Limited | Education | 2021 |
| Traccam Limited | Construction | 2020 |
| Trace Supplier Limited | Information & communication | 2016 |
| Trade Electric Wholesale Ltd | Wholesale & retail | 2005 |
| Trade Price Limited | Wholesale & retail | 1998 |
| Trade Spectrum Limited | Wholesale & retail | 2023 |
| Tradeswap Ltd | Information & communication | 2025 |
| Tradetower Ltd | Professional & scientific | 2012 |
| Tradetower Nominee (1) Limited | Extraterritorial | 2016 |
| Tradetower Nominee (2) Limited | Extraterritorial | 2016 |
| Tradetower Nominee (3) Limited | Extraterritorial | 2016 |
| Tradev Services Limited | Manufacturing | 2024 |
| Tradewings Worldwide Ltd | Wholesale & retail | 2008 |
| Trafalgar Properties and Land Limited | Administrative & support | 2021 |
| Traffiq Solutions Ltd | Professional & scientific | 2024 |
| Trakker Solutions Limited | Information & communication | 2013 |
| Tranquolity Limited | Real estate | 2022 |
| Trans-Britannia Garages Limited | Construction | 1980 |
| Trans-Britannia Properties Limited | Construction | 1979 |
| Trans-European Properties Limited | Construction | 1981 |
| Transcendence Business Consultancy Ltd | Professional & scientific | 2016 |
| Transformation Junction Limited | Information & communication | 2019 |
| Translateable Limited | Administrative & support | 2020 |
| Transmission Limited | Other services | 2015 |
| Transporter 247 Limited | Wholesale & retail | 2018 |
| Travelastic Ltd | Administrative & support | 2022 |
| Travelocto Limited | Administrative & support | 2026 |
| Travelrite Limited | Financial services | 2018 |
| Travlin Style Limited | Administrative & support | 2002 |
| Travlin Style Stanmore Limited | Administrative & support | 2014 |
| TRC Tilers Ltd | Construction | 2017 |
| Treeline Carbon Limited | Agriculture & fishing | 2021 |
| Treleaven Limited | Professional & scientific | 2024 |
| Tri-Tauri Properties Ltd | Real estate | 2020 |
| Triaksha Education Ltd | Education | 2025 |
| Triaksha Intelligence Ltd | Information & communication | 2026 |
| Trickys Vendors Limited | Wholesale & retail | 2023 |
| Triclover Properties Ltd | Real estate | 2015 |
| Trident Information Limited | Manufacturing | 2006 |
| Trikal Limited | Wholesale & retail | 2023 |
| Trillium Enterprise Ltd | Real estate | 2016 |
| Trinetra Earth Limited | Professional & scientific | 2025 |
| Trinity House Real Estate Limited | Real estate | 2017 |
| Triple D Publishing Ltd | Other services | 2019 |
| Triple S MOT Centre Limited | Wholesale & retail | 2009 |
| Triple TEE Services Ltd | Wholesale & retail | 2023 |
| Triplecrest Limited | Extraterritorial | 2000 |
| Trishiv Enterprise Limited | Wholesale & retail | 2025 |
| Tropical Pride Limited | Manufacturing | 2015 |
| Troy D Carpentry Limited | Other services | 2022 |
| Trsfrm Ltd | Administrative & support | 2019 |
| True Health Group Ltd | Wholesale & retail | 2015 |
| True Pleaser UK Ltd | Wholesale & retail | 2025 |
| Trussbow Limited | Wholesale & retail | 2024 |
| Trustient Limited | Extraterritorial | 2005 |
| Trustworthy Estates Ltd | Real estate | 2025 |
| Trutti Frutti Ltd | Wholesale & retail | 2013 |
| TSD Estates LLP | | 2013 |