| Taea Search Consulting Limited | Professional & scientific | 2026 |
| Tashida Recruitment Limited | Administrative & support | 2017 |
| Technology Consult Ltd | Professional & scientific | 2016 |
| TED Handley & Co Limited | Real estate | 2003 |
| THE Affiliator Limited | Wholesale & retail | 2022 |
| THE Brewers Arms Estate Residents Association Limited | Households | 1990 |
| THE Full Fifteen Ltd | Information & communication | 2019 |
| THE Hair Studio (Mayfield) Limited | Other services | 2017 |
| THE Hollies (Mayfield) Limited | Households | 2001 |
| THE London Tanker Exchange Ltd | Wholesale & retail | 2024 |
| THE Pink Cabbage Produce Company Ltd | Wholesale & retail | 2013 |
| THE POT Company (UK) Ltd | Professional & scientific | 2010 |
| THE Potting Shed Cafe Ltd | Wholesale & retail | 2026 |
| THE Rose and Crown Mayfield Ltd | Hospitality | 2018 |
| THE Round Wood (Group) Limited | Other services | 2014 |
| THE User Experience Business Limited | Arts & recreation | 2010 |
| Trac 4 Good Ltd | Information & communication | 2016 |
| Trakehner Cosec Limited | Professional & scientific | 2007 |
| Trunorth Purpose Ltd | Education | 2022 |
| TRY the KIT Limited | Administrative & support | 2020 |
| Twinkles Properties Limited | Real estate | 2018 |
| Twinkles Social Care Ltd | Health & social care | 2021 |
| Ucopia Wines Ltd | Wholesale & retail | 2019 |
| Unequal Productions Limited | Arts & recreation | 2021 |
| Unfkr Ltd | Information & communication | 2019 |
| Upbrook Mews Property Management Company Ltd | Real estate | 2021 |
| V&Co Ltd | Other services | 2022 |
| Vesperra Beauty Ltd | Wholesale & retail | 2024 |
| Virus Power UK Ltd | Wholesale & retail | 2025 |
| Visbe UK Limited | Wholesale & retail | 2016 |
| Ward IT Consultancy Ltd | Information & communication | 2024 |
| Warren Estate Roads Company (Mayfield) Limited | Other services | 1964 |
| Waste Paper Solutions Ltd | Water & waste | 2011 |
| Watsons (South East) Ltd | Professional & scientific | 2014 |
| WE the Creators Ltd | Professional & scientific | 2019 |
| Webinnovationdevelopment Ltd | Information & communication | 2026 |
| Wellbrook Social Club Limited | Hospitality | 2018 |
| West END Telecoms Ltd | Information & communication | 2014 |
| Woodland Building & Property Limited | Construction | 2018 |
| Your Green Heart Limited | Professional & scientific | 2019 |