| Wickes Group PLC | Wholesale & retail | 2019 |
| Wickes Holdings Limited | Extraterritorial | 1983 |
| Wider Web Limited | Information & communication | 2018 |
| Widewings Ltd | Extraterritorial | 2019 |
| Wigmore Kitchen Design Festival Ltd | Information & communication | 2019 |
| Wilby Lodge Limited | Households | 1981 |
| Wilcot Close Management Limited | Administrative & support | 2001 |
| Wild Farm Limited | Agriculture & fishing | 2025 |
| Wild Hare Ltd | Real estate | 2023 |
| Wild Organisations Limited | Professional & scientific | 2016 |
| Wild Quest Digital Limited | Information & communication | 2025 |
| Wildeyes Vision Clinic Ltd | Other services | 2013 |
| Wildfyre Marketing Ltd | Administrative & support | 2023 |
| Wildings Services Ltd | Real estate | 2017 |
| Wildwood Crystal Limited | Wholesale & retail | 1993 |
| Wilfred Webster Talent Limited | Professional & scientific | 2023 |
| Wilko Real Estates Ltd | Real estate | 2021 |
| Wilks Electrical Ltd | Construction | 2025 |
| Willaw Surveys Ltd | Construction | 2014 |
| Willett Lodge Care Home Ltd | Health & social care | 2008 |
| William Lloyd Consulting Ltd | Administrative & support | 2008 |
| William Mcgowan Property Investments LLP | | 2016 |
| William Nicolas Limited | Administrative & support | 2012 |
| Williams Residential (Yorkshire) Ltd | Real estate | 2022 |
| Willoughby Arms Holdings Limited | Hospitality | 2006 |
| Willoughby Arms Limited | Agriculture & fishing | 1998 |
| Willow Ridge Consultancy Ltd | Financial services | 2016 |
| Willow Tree Lodge Management Co. Ltd | Households | 1991 |
| Willowvale Ltd | Professional & scientific | 2011 |
| Wills & Ways Ltd. | Real estate | 2017 |
| Wilma Travels Limited | Extraterritorial | 2012 |
| Wilrin Ltd | Administrative & support | 2014 |
| Wilson & Co Household Management Ltd | Administrative & support | 2026 |
| Wilson Holdings Group Ltd | Wholesale & retail | 2024 |
| Wilson Titian Ltd | Information & communication | 2017 |
| Wilstone Wharf Management RTM Company Ltd | Households | 2017 |
| Wilton Place (Management) Company Limited | Households | 1994 |
| Wimbourne Park Limited | Real estate | 2014 |
| Wimcap Consulting Services Ltd | Information & communication | 2019 |
| Wimoco Hand Car Wash Limited | Other services | 2006 |
| Wimp Holdings Limited | Real estate | 2018 |
| WIN3 Health Solutions Limited | Health & social care | 2012 |
| Winandgrin Ltd | Wholesale & retail | 2024 |
| Winbell Solutions Ltd | Professional & scientific | 2018 |
| Wind Matters Limited | Professional & scientific | 2012 |
| Windermere Court (Management) Limited | Households | 1969 |
| Windev Limited | Information & communication | 1992 |
| Windmill Court (Numbers 1-16 Management) Limited | Households | 1986 |
| Windmill Court Management Limited | Households | 1996 |
| Window and Door Sales Ltd | Administrative & support | 2016 |
| Windsor Court (the Acorns) Residents Association Limited | Real estate | 1995 |
| Winecellars Limited | Wholesale & retail | 1989 |
| Wineify Limited | Wholesale & retail | 2019 |
| Winged Rose Consulting Ltd | Professional & scientific | 2018 |
| Wingrove Capital Ltd | Real estate | 2024 |
| Winlabs Limited | Information & communication | 2020 |
| Winreb Finance Limited | Administrative & support | 1969 |
| Winsford Court Hendon (Management) Limited | Households | 2012 |
| Wintertime Properties Limited | Real estate | 2004 |
| Winz Limited | Professional & scientific | 2014 |
| WIP Outsourcing Ltd | Administrative & support | 2022 |
| Wippendale Limited | Professional & scientific | 2011 |
| Wirebox Ltd | Information & communication | 2011 |
| Wired Productions Limited | Information & communication | 2008 |
| Wise Compass Ltd | Information & communication | 2025 |
| Wise Foods GH Ltd | Hospitality | 2025 |
| Wise Oak Psychology Limited | Health & social care | 2020 |
| Wise Technical Limited | Professional & scientific | 2015 |
| Wiseanalytix Ltd | Information & communication | 2024 |
| Wisecare Assistance Ltd | Administrative & support | 2025 |
| Withcare Cleaning Ltd | Administrative & support | 2011 |
| Withcare Estate Management Ltd | Administrative & support | 2013 |
| Wivenhoe Court (Hounslow) Management Company Limited | Households | 1985 |
| Wizard HR Ltd | Other services | 2018 |
| Wizcare Consulting Limited | Health & social care | 2014 |
| Wizrad Limited | Extraterritorial | 2010 |
| Wizzbiz Ltd | Public administration | 2025 |
| WJN Property Limited | Real estate | 2019 |
| WK Solicitors Limited | Professional & scientific | 2026 |
| Wkjd Ltd | Real estate | 2021 |
| WLT Consulting Limited | Administrative & support | 2012 |
| WLT Management Ltd | Hospitality | 2025 |
| WM Harrow Ltd | Wholesale & retail | 2025 |
| WM IT Projects Ltd | Information & communication | 2011 |
| WMA Consultancy Services Ltd | Professional & scientific | 2019 |
| WMO Property Development Limited | Real estate | 2017 |
| WMR Appleby Ltd | Real estate | 2022 |
| WNA Gems and Jewels Ltd | Wholesale & retail | 2018 |
| Wnorberth Ltd | Transport & logistics | 2019 |
| Woj-Tec Building Plumbing GAS Heating Limited | Construction | 2015 |
| Woka Ltd | Hospitality | 2022 |
| Wolf & Brown Limited | Construction | 2012 |
| Wolf and Young Limited | Construction | 2010 |
| Wolf Marketing Ltd | Professional & scientific | 2025 |
| Wolf Software Systems Ltd | Professional & scientific | 2021 |
| Wolf Wood Carpenter Ltd | Manufacturing | 2024 |
| Wolfe Bushire Ltd | Transport & logistics | 2025 |
| Wolff Holdings Limited | Professional & scientific | 2019 |
| Wolfpack Holdings Ltd | Construction | 2018 |
| Wolsey Charitable Trust | Education | 2006 |