| THE Reach Foundation | Education | 2008 |
| THE Rubbish Guys Limited | Water & waste | 2024 |
| THE Skin Nurse Ltd | Wholesale & retail | 2017 |
| THE Social Club Hanworth | Other services | 2023 |
| THE Sports Car Center Ltd | Wholesale & retail | 2024 |
| THE ST Michael Steiner School Limited | Education | 2002 |
| THE Takeout Food Ltd | Hospitality | 2026 |
| THE Third Floor Ltd | Wholesale & retail | 2026 |
| THE Tile & Bath LAB Ltd | Wholesale & retail | 2026 |
| THE Training and Compliance Hub Limited | Professional & scientific | 2017 |
| THE Turbowood Estate Limited | Real estate | 2026 |
| THE Underfloor Heating Supplier Ltd | Wholesale & retail | 2024 |
| THE Wicked Flames Ltd | Hospitality | 2023 |
| THE Wild Graze Co. Limited | Hospitality | 2025 |
| THE Wrap Lads Ltd | Construction | 2025 |
| THE Wreath Co Limited | Wholesale & retail | 2021 |
| THE3SIXTYCOMPANY Ltd | Other services | 2018 |
| Theleatherhub-Uk Limited | Wholesale & retail | 2025 |
| Themartland Limited | Wholesale & retail | 2021 |
| Theo PDG Ltd | Construction | 2020 |
| Theonlychauffeur Ltd | Transport & logistics | 2024 |
| Theramira Ltd | Health & social care | 2025 |
| Therightway Ltd | Transport & logistics | 2020 |
| Thermo Solutions Ltd | Construction | 2019 |
| Thespineandsoul Ltd | Health & social care | 2026 |
| Thistle Gilt Ltd | Wholesale & retail | 2026 |
| Thomas Plumbers 24H Ltd | Construction | 2026 |
| Thor Parker Ltd | Wholesale & retail | 2019 |
| Three Horseshoes Feltham Ltd | Hospitality | 2026 |
| Three Horseshoes Limited | Hospitality | 2020 |
| TI Construction Ltd | Construction | 2020 |
| Tian Tian UK Trading Limited | Wholesale & retail | 2016 |
| Tide Casting Limited | Administrative & support | 2018 |
| Tide Power Limited | Energy | 2022 |
| Tiffani-Cars Ltd | Transport & logistics | 2019 |
| Tiles & Worktops Limited | Manufacturing | 2011 |
| Timbawood Direct Limited | Construction | 2009 |
| Timbawood Limited | Manufacturing | 2007 |
| Timbawood Trade Limited | Other services | 2021 |
| Timconst Ltd | Construction | 2024 |
| Time 2 Shine and Sparkle Ltd | Administrative & support | 2024 |
| Time Essence Build Ltd. | Construction | 2017 |
| Timeki Ltd | Health & social care | 2022 |
| Timeless Finishes Ltd | Construction | 2025 |
| Tiny Hands Locs Ltd | Other services | 2020 |
| Tiptop Builders Limited | Construction | 2013 |
| Tirean Limited | Construction | 2024 |
| Titan Cars 105 Limited | Wholesale & retail | 2021 |
| Tjamma Services Ltd | Information & communication | 2021 |
| TK Automation Solutions Limited | Manufacturing | 2016 |
| TK Construction NW Ltd | Real estate | 2022 |
| Tlwa Services Ltd | Construction | 2026 |
| TM UK Property Services Limited | Construction | 2025 |
| TMT Renovations Ltd | Construction | 2018 |
| TND People Limited | Professional & scientific | 2020 |
| Toga Logistics Ltd | Transport & logistics | 2018 |
| Toggle Games Ltd | Information & communication | 2023 |
| Toile Limited | Administrative & support | 2023 |
| Tolf UK Limited | Transport & logistics | 2020 |
| Toll Perishables (UK) Limited | Transport & logistics | 2009 |
| TOM Delivery Ltd | Transport & logistics | 2026 |
| Tomas Joiner Limited | Construction | 2015 |
| Toms Investment Limited | Real estate | 2024 |
| Toovaa Healthcare Solutions Limited | Professional & scientific | 2015 |
| Top Cutz Limited | Other services | 2016 |
| Top Landmark Investment Limited | Real estate | 2025 |
| Top SAP Consultants Ltd | Information & communication | 2024 |
| Top Talent Tutors Ltd | Administrative & support | 2020 |
| Topheatwork's Ltd. | Construction | 2016 |
| Topline Home Improvements Ltd | Construction | 2026 |
| Topsec Security Ltd | Administrative & support | 2025 |
| Topstone Limited | Wholesale & retail | 2025 |
| Toptech Wholesale Ltd | Wholesale & retail | 2025 |
| Torsten Security Services Ltd | Administrative & support | 2024 |
| Total Staff Recruitment Limited | Administrative & support | 2017 |
| Touropedia Ltd | Administrative & support | 2025 |
| Tourvest Duty Free (UK) Limited | Wholesale & retail | 2004 |
| Town Craft Group Ltd | Wholesale & retail | 2026 |
| TPM Security Ltd | Administrative & support | 2025 |
| TR3 Limited | Health & social care | 2026 |
| Trade Minders Ltd | Wholesale & retail | 2024 |
| Trade-Ex Limited | Wholesale & retail | 2024 |
| Trader Declaration & Compliance Services Ltd | Transport & logistics | 2020 |
| Traders Hub Wholesale Ltd | Other services | 2026 |
| Trann Ltd | Real estate | 2020 |
| Trans Europe Trade Company Ltd | Wholesale & retail | 2024 |
| Trans MK Ltd | Transport & logistics | 2022 |
| Transalpine Enterprises Holdings Limited | Information & communication | 2010 |
| Transalpine Enterprises Limited | Information & communication | 2001 |
| Transcontinental Blue Ltd | Wholesale & retail | 2023 |
| Translations Express Online Limited | Professional & scientific | 2014 |
| Translations Express UK Online Ltd | Professional & scientific | 2010 |
| Travel Holidays Limited | Administrative & support | 2023 |
| Travel Miles With US Limited | Administrative & support | 2018 |
| Travelglob Ltd | Wholesale & retail | 2023 |
| Treasured Leather Ltd | Manufacturing | 2025 |
| Trend Scholar Ltd | Information & communication | 2026 |
| Trendblend Ltd | Wholesale & retail | 2025 |
| Tribeca Investments Ltd | Real estate | 2016 |
| Tribos Dessert and Burger Limited | Hospitality | 2022 |