| WG4 Developments Limited | Construction | 2020 |
| Wgdb Ltd | Professional & scientific | 2017 |
| What IS Possible Ltd | Professional & scientific | 2003 |
| Whataeon Limited | Households | 1981 |
| Whatagwan Caribbean Bar & Grill Ltd | Hospitality | 2022 |
| Whatman House Management Company Limited | Households | 2022 |
| Whatzon Limited | Information & communication | 2016 |
| WHD PR Limited | Professional & scientific | 2003 |
| Whealth Group Limited | Health & social care | 2025 |
| Wheat and Cheese Limited | Financial services | 2022 |
| Wheelers Court (Swadlincote) Management Company Limited | Households | 2007 |
| WHERE4 Ltd | Other services | 2017 |
| Whetstone Chemist Ltd | Wholesale & retail | 2006 |
| Whetstone Gardens Residents' Management Company Limited | Households | 2021 |
| Whisked Away by Morgan Ltd | Wholesale & retail | 2025 |
| Whitaker Consulting Limited | Professional & scientific | 2017 |
| White Dragon International Ltd | Professional & scientific | 2015 |
| White Glacier Ltd | Administrative & support | 2023 |
| White Hats Maintenance and Cleaning Contractors Ltd | Construction | 2022 |
| White Haus Holdings Limited | Financial services | 2017 |
| White House (Eaton Socon) Management Company Limited(The) | Households | 1984 |
| White HUT Studios in Education CIC | Education | 2021 |
| White HUT Studios Limited | Other services | 2018 |
| White Label Publishing Ltd | Professional & scientific | 2009 |
| White Post Partners Ltd | Hospitality | 2026 |
| White Rabbit London Ltd | Wholesale & retail | 2019 |
| White Shark Facilities Service Ltd | Other services | 2013 |
| White Stork Global Limited | Construction | 2023 |
| White Systems Consulting Ltd | Professional & scientific | 2020 |
| White Valley Ltd | Professional & scientific | 2015 |
| White Wolf Security Ltd | Administrative & support | 2019 |
| Whiteco Limited | Extraterritorial | 2015 |
| Whitegate Place (Littler Lane) Management Company Limited | Households | 2013 |
| Whitehaven Close Limited | Households | 2005 |
| Whitehorse Road Development Ltd | Real estate | 2013 |
| Whiteline Investments Limited | Administrative & support | 2009 |
| Whitepost Management Limited | Households | 2002 |
| Whitgift Construction C.I.C. | Construction | 2010 |
| Whitgift School International Limited | Education | 2023 |
| Whitminster Store Ltd | Wholesale & retail | 2022 |
| Whitstable Place (Croydon) Management Company Limited | Households | 1997 |
| Whittaker Court Residents Management Limited | Households | 1987 |
| Whittles Newsagent Limited | Extraterritorial | 2017 |
| Whitton Grange Management Company Limited | Households | 1999 |
| Whizz Kidz Nurseries Ltd | Health & social care | 2014 |
| Wholesale Catering Ltd | Wholesale & retail | 2020 |
| Wholesalo Limited | Wholesale & retail | 2023 |
| Wholesome and Healthy Limited | Wholesale & retail | 2020 |
| Wholistic Care and Supported Living Limited | Health & social care | 2017 |
| Why-Axis Ltd | Professional & scientific | 2016 |
| Whyteleafe Football Club Ltd | Arts & recreation | 2019 |
| WI GAS Services Ltd | Construction | 2016 |
| WI Genie Ltd | Information & communication | 2026 |
| WI Ltd | Hospitality | 2006 |
| Wickets Residents Management Limited | Households | 1989 |
| Wickford House (Management) Limited | Households | 1961 |
| Wickham Cleaning Ltd | Other services | 2012 |
| Wickham Gardeneers Ltd | Extraterritorial | 2013 |
| Wickham Gensol Limited | Administrative & support | 2009 |
| Wide Area Communications Limited | Information & communication | 1992 |
| Wideview Recruitment Ltd | Professional & scientific | 2016 |
| Wiggy Group Ltd | Manufacturing | 2022 |
| Wigmore Fields Management Company Number 2 Limited | Households | 2004 |
| Wigs Pet Spa Ltd | Wholesale & retail | 2022 |
| Wikaclily Capital Limited | Administrative & support | 2013 |
| Wikilift Ltd | Construction | 2020 |
| Wikvibuild.Ltd Limited | Construction | 2019 |
| Wilcomatic Limited | Administrative & support | 1967 |
| Wilcomatic Rail Limited | Administrative & support | 2026 |
| Wilcomatic Rail Systems Limited | Administrative & support | 2026 |
| Wilcomatic Rail Wash Systems Limited | Administrative & support | 2026 |
| Wild Bass Ltd | Wholesale & retail | 2023 |
| Wild Fennel Creations Ltd | Wholesale & retail | 2022 |
| Wild in the City CIC | Health & social care | 2016 |
| Wild Republic UK Ltd | Wholesale & retail | 1997 |
| Wild Yonder Ltd | Professional & scientific | 2017 |
| Wilde and Webb Ltd | Professional & scientific | 2018 |
| Wildlife Wonders Ltd | Education | 2023 |
| Wildman Transport Ltd | Transport & logistics | 2025 |
| Wilkin Constructions Ltd | Other services | 2017 |
| Will Drafters Limited | Professional & scientific | 1990 |
| Will Estates Limited | Real estate | 2022 |
| Will Prosper Ltd | Wholesale & retail | 2025 |
| Will Storage (London) Limited | Professional & scientific | 2008 |
| Willans Green (Rugby) Management Company Limited | Households | 2004 |
| William Bulman Educational Psychology Limited | Health & social care | 2023 |
| William Court Residents Association (Uxbridge) Limited | Households | 1984 |
| William Cross Consultancy Ltd | Administrative & support | 2010 |
| William IT Ltd. | Information & communication | 2018 |
| William Mason Consultancy Limited | Construction | 2023 |
| William Registrars Limited | Other services | 1972 |
| William Walk Management Limited | Households | 2006 |
| William Way (Godstone) Residents Management Company Limited | Households | 2019 |
| William's Engineering Limited | Professional & scientific | 2016 |
| Williams Elite Property Ltd | Real estate | 2025 |
| Williams Healthcare Solutions Ltd | Administrative & support | 2021 |
| Williams of Swansea Ltd | Wholesale & retail | 1998 |
| Willicote Pastures Management Limited | Households | 1996 |
| Willington Lane (Kelsall) Management Limited | Households | 2015 |
| Willmead Limited | Construction | 1972 |