| Walker Auto Engineer's Ltd | Wholesale & retail | 2023 |
| Walkers(Chemists)Limited | Real estate | 1961 |
| Warbeck Investments PUB Group Limited | Hospitality | 2015 |
| Warma Properties Ltd | Real estate | 2013 |
| Warwick Flat 8 Limited | Real estate | 2022 |
| Watford Ladies Academy FC Ltd | Education | 2020 |
| Watford PAT Testing Ltd | Professional & scientific | 2025 |
| WD Skips Limited | Water & waste | 2014 |
| WD23 Food Ltd | Hospitality | 2024 |
| WD23 Ltd | Real estate | 2025 |
| WDB Construction Ltd | Construction | 2026 |
| WE Like Good Pizza Limited | Hospitality | 2025 |
| Wedderhall Ltd | Real estate | 2013 |
| Wellfi Limited | Wholesale & retail | 2025 |
| Wells Homes (Norfolk) Limited | Professional & scientific | 2004 |
| Wembley Prestige Cars Limited | Wholesale & retail | 2004 |
| Wembley Services Ltd | Professional & scientific | 2023 |
| West Alliance Construction Limited | Construction | 2010 |
| Westnorth Ltd | Real estate | 1993 |
| Weston Road Property Company Limited | Real estate | 1961 |
| Weststar Property Services Limited | Construction | 2025 |
| Whipnae Limited | Wholesale & retail | 2022 |
| White Collar Grappling Ltd | Education | 2025 |
| White Sapphire Properties Ltd | Real estate | 2018 |
| Whitepaper Events Limited | Other services | 2012 |
| Wicky Reach Limited | Wholesale & retail | 2025 |
| Wild Compass Ltd | Arts & recreation | 2019 |
| Wildhire Recruitment Ltd | Administrative & support | 2024 |
| Will Sanders Photography Ltd | Professional & scientific | 2019 |
| William Rees Limited | Arts & recreation | 2016 |
| Willingham Partnership Ltd | Administrative & support | 2013 |
| Willows RTM Company Limited | Extraterritorial | 2026 |
| Wing Electrical Limited | Manufacturing | 2014 |
| Wingman Advocacy Ltd | Administrative & support | 2026 |
| Wise OWL Education Limited | Extraterritorial | 2017 |
| Witan Consulting Ltd | Professional & scientific | 2019 |
| Wizworks Limited | Professional & scientific | 2026 |
| WMG Building Services Ltd | Construction | 2010 |
| Woburn Advisory Limited | Administrative & support | 2011 |
| Wombat Investments 5 Limited | Real estate | 2022 |
| Womeno Supplements Ltd | Wholesale & retail | 2024 |
| Wright Productions Ltd | Information & communication | 2020 |
| Writing & Editing Consultancy Ltd | Information & communication | 2018 |
| WW Kitchens Ltd | Hospitality | 2022 |
| WWR Property Ltd | Real estate | 2016 |
| Wymer Electrical Limited | Construction | 1976 |
| Wyse Decorative Solutions Ltd | Construction | 2025 |
| XCX Consulting Ltd | Professional & scientific | 2025 |
| Xotic Food Limited | Hospitality | 2025 |
| Yates Property Services Ltd | Construction | 2018 |
| YDL Automotive Ltd | Wholesale & retail | 2025 |
| YML Professional Services Limited | Professional & scientific | 2018 |
| YNV Properties Limited | Real estate | 2013 |
| York ROW (Holdings) Limited | Real estate | 1992 |
| Young Music Makers London Limited | Education | 1967 |
| Young Scale Media Ltd | Professional & scientific | 2025 |
| YUM Thai Ltd | Hospitality | 2020 |
| Yumei Limited | Administrative & support | 2017 |
| Yuneeko London Ltd | Wholesale & retail | 2020 |
| Z.Cat Ltd | Construction | 2025 |
| Zainedi Ltd | Wholesale & retail | 2025 |
| Zamzam Houses Limited | Real estate | 2022 |
| Zarsk Homes Limited | Real estate | 2017 |
| Zarsk Ltd | Information & communication | 2015 |
| Zarsk Properties Ltd | Real estate | 2017 |
| Zaylomart Ltd | Wholesale & retail | 2025 |
| ZBS Imperial Ltd | Health & social care | 2026 |
| ZD Property Limited | Information & communication | 2017 |
| ZEN Tours Yoni Ltd | Administrative & support | 2025 |
| Zengold Limited | Professional & scientific | 1999 |
| Zenith Auto Imports London Ltd | Wholesale & retail | 2024 |
| Zero Alcohol Co Ltd | Other services | 2026 |
| Zeta Ltd | Administrative & support | 2021 |
| £Lush Ltd | Wholesale & retail | 2020 |