| THE Turkish Aviation Academy of Cyprus Limited | Extraterritorial | 2014 |
| THE Tyre Corporation Limited | Wholesale & retail | 1996 |
| THE Urban Greek Ltd | Hospitality | 2019 |
| THE Wheel Guys Limited | Wholesale & retail | 2020 |
| THE Winning Margin Ltd | Wholesale & retail | 2017 |
| THE World Peace Organisation Limited | Extraterritorial | 2007 |
| Thearthurovens Ltd | Wholesale & retail | 2025 |
| Theflo Limited | Financial services | 2024 |
| Theivalayam Tamil Cultural Centre Ltd | Education | 2019 |
| Theo Group Ltd. | Real estate | 2025 |
| Therisebookkeeping Limited | Professional & scientific | 2021 |
| Thetis Holdings Ltd | Professional & scientific | 2021 |
| Think Events (London) Limited | Arts & recreation | 2010 |
| Thinking Like a Designer Ltd | Professional & scientific | 2015 |
| Thirsty Thursday Consulting Ltd | Professional & scientific | 2024 |
| Thomas O Brian Property Maintenance Limited | Construction | 2025 |
| Thomas Telman Consulting Ltd | Administrative & support | 2010 |
| Thornbeal Limited | Real estate | 2024 |
| Three Group (London) Limited | Real estate | 2024 |
| Thrivel Ltd | Information & communication | 2007 |
| Tiffany Paul Property Development Ltd | Real estate | 2026 |
| Tiger Catering (Croydon) Ltd | Hospitality | 2018 |
| Timeless Dreams Ltd | Real estate | 2024 |
| Timeless Whisky Ltd | Wholesale & retail | 2025 |
| Times Square Estates Limited | Real estate | 2001 |
| Tinderbox Digital Ltd | Professional & scientific | 2023 |
| TIP Top Waste Clearance Ltd | Water & waste | 2025 |
| Tiro Fitness Ltd | Arts & recreation | 2019 |
| Titan Print Management Limited | Manufacturing | 2021 |
| Tixa Ltd | Professional & scientific | 2013 |
| TJ M & E Consultant Limited | Professional & scientific | 2022 |
| Tlta Ltd | Administrative & support | 2017 |
| TMI Construction Ltd | Construction | 2024 |
| TMM Global Consulting Ltd | Wholesale & retail | 2025 |
| Together 4EVER C.I.C. | Administrative & support | 2019 |
| Tootsie Sopat Limited | Real estate | 2026 |
| Top & RAK Limited | Hospitality | 2019 |
| Top Decorators Ltd | Construction | 2023 |
| Top Grade Tuition Ltd | Education | 2025 |
| Top Stitch Tailor Limited | Manufacturing | 2025 |
| Topco Holdings Limited | Extraterritorial | 2019 |
| Topgun Ventures Limited | Information & communication | 2006 |
| Torch Scaffolding Limited | Construction | 1995 |
| Total Grey Limited | Wholesale & retail | 2021 |
| Total Jobs Limited | Extraterritorial | 2017 |
| Totstars Ltd | Arts & recreation | 2010 |
| Totstars Toby's Adventure Club Ltd | Arts & recreation | 2015 |
| Toupret (UK) Limited | Construction | 2004 |
| TOW 2 TOW Transport Ltd | Transport & logistics | 2026 |
| Towans Services Limited | Health & social care | 2019 |
| Towzilla Transport Ltd | Water & waste | 2025 |
| TP Property Developers Limited | Construction | 2026 |
| TRA London Limited | Real estate | 2010 |
| TRA Surrey Limited | Real estate | 2022 |
| Trace Homes Limited | Real estate | 2022 |
| Tradeagents Ltd | Real estate | 1999 |
| Trained to BE Ltd | Health & social care | 2023 |
| Tramore Construction Ltd | Construction | 2008 |
| Transition Housing | Real estate | 2018 |
| Travelent Premium Travel Management Ltd | Administrative & support | 2026 |
| Treetops Consulting Ltd | Information & communication | 2018 |
| Trending Goods Limited | Wholesale & retail | 2022 |
| Trendsetter Concierge Ltd | Wholesale & retail | 2024 |
| Tridecimal Limited | Information & communication | 2009 |
| Trinistyle Luxury Properties Ltd | Real estate | 2026 |
| Trinity Mid-Whitgiftian Association Limited | Other services | 1948 |
| Trinity Sanderstead Sports & Social Club Limited | Arts & recreation | 2015 |
| TRU People Limited | Administrative & support | 2022 |
| Trudo Limited | Professional & scientific | 2015 |
| True Building Ltd. | Administrative & support | 2016 |
| True Electrical & Mechanical Ltd. | Construction | 2015 |
| True Grip (South) Limited | Construction | 2020 |
| True Grip Eco Clean Ltd | Administrative & support | 2008 |
| True Grip Limited | Construction | 2003 |
| True Grip Surfacing Limited | Construction | 2023 |
| Truestone Construction Ltd | Construction | 2021 |
| Truestone National Ltd | Construction | 2026 |
| TRY Villa Management FR Ltd | Hospitality | 2014 |
| TS 786 Ltd | Extraterritorial | 2016 |
| Tsap Developments Ltd | Construction | 2026 |
| TSD Carpentry & Structures Limited | Other services | 2024 |
| TTC Holdings Ltd | Financial services | 2024 |
| TTU Experiences Ltd | Administrative & support | 2020 |
| Tune Roofing Ltd | Construction | 2021 |
| Turco Motorcycle Ltd | Wholesale & retail | 2022 |
| Turksezer Catering Ltd | Hospitality | 2020 |
| Turpak Limited | Administrative & support | 2023 |
| Tuscan Technology Limited | Information & communication | 2003 |
| Tusciainside Ltd | Administrative & support | 2019 |
| Tuvana Turkay Ltd | Information & communication | 2020 |
| TWC Locksmith Services Ltd | Manufacturing | 2026 |
| Twelve Towers Ltd | Real estate | 2023 |
| TWM Catlin Ltd | Households | 2023 |
| Two Brothers Cafe Ltd | Hospitality | 2003 |
| Two Group London Limited | Construction | 2024 |
| Two on the Go Limited | Hospitality | 2007 |
| Twoj Prospekt Ltd | Professional & scientific | 2018 |
| TYM Leaflets Distribution Ltd | Transport & logistics | 2021 |
| Tymz Properties Ltd | Real estate | 2025 |
| Typelab Ltd | Professional & scientific | 2020 |