| Synhern CSM Limited | Construction | 2017 |
| T W I London Limited | Real estate | 1994 |
| Tailgate Media Limited | Other services | 2017 |
| Talisman Gallery Limited | Wholesale & retail | 1980 |
| Telma | | 2001 |
| Terik Limited | Professional & scientific | 1998 |
| Thames Associates Limited | Professional & scientific | 1996 |
| THE Eagles Management Company Limited | Extraterritorial | 2017 |
| THE Essential Housewares Company Limited | Wholesale & retail | 1993 |
| THE Failed Politician Ltd | Information & communication | 2020 |
| THE Healthlink Group Limited | Health & social care | 2018 |
| THE Personal Web Company Ltd | Information & communication | 2011 |
| THE Radiology Apothecary Ltd | Health & social care | 2020 |
| THE Rising Sun Mill Hill LLP | | 2013 |
| Tiens UK Limited | Wholesale & retail | 2001 |
| Tom's Creations Limited | Information & communication | 2021 |
| Tony Lampert Consulting Limited | Education | 2017 |
| Top Irrigation Limited | Extraterritorial | 2006 |
| Town & Country Restorations Limited | Construction | 2021 |
| Trade Kitchens (NWL) Limited | Wholesale & retail | 2013 |
| Travel Smarter Ltd | Administrative & support | 2025 |
| TUA Interiors Limited | Professional & scientific | 2014 |
| TUA Office Furniture Limited | Wholesale & retail | 2024 |
| Tudoroak Limited | Construction | 1989 |
| Tulipwood Limited | Real estate | 2001 |
| U Creative Communications Limited | Information & communication | 2004 |
| Ultrahome Limited | Real estate | 2000 |
| Ultrahome Properties Limited | Extraterritorial | 2021 |
| Ultratown Investments Limited | Real estate | 1987 |
| Ultratown Limited | Administrative & support | 1985 |
| Ultratown Norwich Limited | Extraterritorial | 2024 |
| Underline Utilities & Civil Engineering Ltd | Construction | 2023 |
| Underwoods Investments Limited | Extraterritorial | 1998 |
| V Palade Limited | Construction | 2014 |
| Vascular Therapies Limited | Health & social care | 2018 |
| Veh-Com Limited | Information & communication | 2007 |
| Vered Consulting Limited | Other services | 2015 |
| Vicki Hopps Productions Limited | Arts & recreation | 2002 |
| Victoria Way Management Company (Charlton Phase 2) Limited | Real estate | 2018 |
| Viona Beauty Ltd | Health & social care | 2020 |
| Virtplatforms Ltd | Information & communication | 2019 |
| Virtually Bespoke Limited | Professional & scientific | 2021 |
| Web Automatic Limited | Professional & scientific | 2001 |
| Wedgewood Property Limited | Real estate | 1982 |
| Welwyn Garden Estates Limited | Real estate | 2003 |
| West 1 Pubs 2 Limited | Hospitality | 2024 |
| West END & City Properties Limited | Financial services | 1995 |
| Westcourt Art | | 2001 |
| Westone Properties Limited | Real estate | 1998 |
| Wingate Advisers Ltd | Professional & scientific | 2010 |
| Winsyl Investments Limited | Real estate | 1964 |
| WJC International Limited | Arts & recreation | 2007 |
| WOW Grooming Limited | Wholesale & retail | 2017 |
| Xenos Ltd | Other services | 2000 |
| Zenith ABS Ltd | Construction | 2011 |
| Zinc Fence Limited | Professional & scientific | 1992 |
| ZMI Consultancy Ltd | Information & communication | 2023 |
| Zoref Limited | Wholesale & retail | 2023 |