| THE Street Deli Limited | Wholesale & retail | 2019 |
| THE Training Studio Limited | Information & communication | 1997 |
| THE Walsh Academy Ltd | Education | 2021 |
| THE Way BBQ Ltd | Hospitality | 2016 |
| THE Way Forward Ltd | Administrative & support | 2016 |
| THE Window Blind Company (London) Ltd | Construction | 2020 |
| Theydon Investments Limited | Professional & scientific | 2018 |
| Thor Acquisitions Limited | Financial services | 2023 |
| Thorpbuild Limited | Construction | 2014 |
| Thsl Limited | Real estate | 2017 |
| TI Electrical Services Ltd | Construction | 2020 |
| Tichi Holdings Limited | Professional & scientific | 2010 |
| Tilak Ortho Services Limited | Health & social care | 2016 |
| Timber Tech Twins Ltd | Construction | 2023 |
| Timpani Group Limited | Information & communication | 2015 |
| Timroe Accounting Services Ltd | Professional & scientific | 2014 |
| TIP Physio Ltd | Health & social care | 2016 |
| Tiptop Excellence Ltd | Manufacturing | 2026 |
| TJT London Ltd | Other services | 2024 |
| TM EYE E Secure Ltd | Administrative & support | 2021 |
| TM EYE Global Limited | Other services | 2021 |
| TM EYE Limited | Public administration | 2007 |
| TMH Research Limited | Administrative & support | 2011 |
| Toca Creative Ltd | Professional & scientific | 2018 |
| Tomm Construction Limited | Construction | 2025 |
| Toni-Em Ltd | Construction | 2013 |
| Tonton EV Ltd | Real estate | 2025 |
| Toothology Limited | Health & social care | 2017 |
| Top Dog Grooming Studio Limited | Other services | 2004 |
| Top Resourceful Solutions Limited | Other services | 2014 |
| Tosam Enterprise Services Limited | Administrative & support | 2026 |
| Tour Design Limited | Administrative & support | 2002 |
| Tour Digital Limited | Other services | 2016 |
| Traderoute Consultants Ltd | Information & communication | 1997 |
| Traders & General Insurance Services Limited | Financial services | 1967 |
| Tradewise Autos Ltd | Wholesale & retail | 2025 |
| Traffic Label Limited | Information & communication | 2006 |
| Trakmasters Limited | Wholesale & retail | 2024 |
| Transnas Ltd | Transport & logistics | 2018 |
| TRE Builders Limited | Construction | 2003 |
| Treats on the House Limited | Wholesale & retail | 2018 |
| Trenchard Close Residents Company Limited | Households | 1997 |
| Trenwith Properties Limited | Real estate | 2017 |
| Trexel Limited | Professional & scientific | 2001 |
| Trinity VM Ltd | Real estate | 2023 |
| Trio Cleaning Group Ltd | Administrative & support | 2026 |
| Trotters Independent Trading Company (UK) Ltd | Wholesale & retail | 2014 |
| TS Petrov Ltd | Construction | 2026 |
| TSF Advisory Services Ltd | Professional & scientific | 2025 |
| TT Q&A Limited | Information & communication | 2013 |
| Ttmsqa Limited | Information & communication | 2025 |
| Tulcho Service Ltd | Transport & logistics | 2014 |
| Turgon Contracts Ltd | Construction | 2024 |
| Turgon Limited | Administrative & support | 2010 |
| Twelve O'Clock Club Ltd | Wholesale & retail | 2024 |
| Twilight Investment Properties Ltd | Real estate | 2020 |
| Twisted Laminator (Composites) Ltd | Manufacturing | 2022 |
| Two Sugars Virtual Assistance Limited | Administrative & support | 2017 |
| Tyresavers (UK) Limited | Wholesale & retail | 2013 |
| U & Z Company Limited | Real estate | 2003 |
| U Zafar Ltd | Health & social care | 2024 |
| Uaworkers Limited | Construction | 2019 |
| UK Pianos Limited | Wholesale & retail | 2026 |
| UK Property Group Limited | Extraterritorial | 2021 |
| Ultimate Signings Ltd | Wholesale & retail | 2023 |
| Uncle Sam's Heating & Plumbing Ltd | Construction | 2022 |
| UNI Alliances Ltd | Hospitality | 2022 |
| Unique 8 Ltd | Administrative & support | 2011 |
| Unique Facilities Ltd | Administrative & support | 2024 |
| Uniquevibes.Co Ltd | Manufacturing | 2022 |
| UPP Catering Limited | Hospitality | 2025 |
| Urban 6 Ltd | Professional & scientific | 2024 |
| Urban GEM Properties Ltd | Real estate | 2023 |
| Urban Visuals & Effects Limited | Information & communication | 2016 |
| Usve Ltd | Arts & recreation | 2024 |
| V&M Holdings Ltd | Financial services | 2019 |
| Valley Dental Practice Ltd | Health & social care | 2023 |
| Valtronic Electrical Limited | Other services | 1999 |
| Vancootan Collective Ltd | Administrative & support | 2025 |
| Vanity Fair Investments Limited | Real estate | 2016 |
| Vbagga Limited | Real estate | 2013 |
| Vbagga Residential Ltd | Real estate | 2021 |
| VC Facility Services Ltd | Administrative & support | 2015 |
| Vector Data Labs Limited | Information & communication | 2024 |
| Verseo Health & Beauty Limited | Wholesale & retail | 2011 |
| Vertical Fashion Limited | Information & communication | 2024 |
| Vibury Ltd | Construction | 2014 |
| Victoria Intelligence Ltd | Information & communication | 2023 |
| Views Event Limited | Professional & scientific | 2024 |
| VIK Consult Ltd | Construction | 2023 |
| Vindici Properties Limited | Real estate | 2015 |
| Virdi Estates Limited | Real estate | 2019 |
| Virtus Prime Ltd | Real estate | 2022 |
| VM & Sons Services Ltd | Transport & logistics | 2018 |
| Volition Inc Ltd | Administrative & support | 2023 |
| Volition.Work Ltd | Administrative & support | 2022 |
| Volumus Limited | Financial services | 2013 |
| Voucher Solutions Limited | Households | 2002 |
| Voucher Systems Limited | Other services | 1994 |
| VR Contracts Ltd | Administrative & support | 2017 |