| Wessex Care Holmwood Limited | Health & social care | 2014 |
| Wessex Care Kimberly House Limited | Extraterritorial | 2014 |
| Wessex Care Limited | Health & social care | 2003 |
| Wessex Care Little Manor Limited | Extraterritorial | 2014 |
| Wessex Care Milford Manor Limited | Extraterritorial | 2014 |
| Wessex Cottages Ltd | Agriculture & fishing | 2007 |
| Wessex Endosurgical Academy Limited | Health & social care | 2026 |
| Wessex Energy Storage Ltd | Professional & scientific | 2021 |
| Wessex Equestrian Ltd | Agriculture & fishing | 2018 |
| Wessex Events Limited | Administrative & support | 2004 |
| Wessex EYE Care Limited | Health & social care | 2015 |
| Wessex Fabrications (Holdings) Limited | Professional & scientific | 2006 |
| Wessex Fabrications Limited | Manufacturing | 1988 |
| Wessex Fabrications Southampton Limited | Financial services | 2018 |
| Wessex Funeral Services Limited | Other services | 2013 |
| Wessex GBG Limited | Real estate | 2024 |
| Wessex Hand Clinic Limited | Health & social care | 2010 |
| Wessex International Holdings Limited | Financial services | 2024 |
| Wessex Local Medical Committees Limited | Professional & scientific | 2006 |
| Wessex Publishing Ltd | Information & communication | 2021 |
| Wessex Rheumatology Limited | Health & social care | 2014 |
| Wessex Scientific Limited | Professional & scientific | 2003 |
| Wessex Swim School Limited | Arts & recreation | 2008 |
| Wessex Trading Ltd | Professional & scientific | 2013 |
| Wessex Training Consultancy Limited | Administrative & support | 2011 |
| Wessex Tyres Ltd | Wholesale & retail | 2014 |
| West Down Properties Limited | Construction | 1998 |
| West Highland Ventures Limited | Construction | 2003 |
| West Quay Limited | Wholesale & retail | 1986 |
| Westgate Builders Limited | Construction | 2008 |
| Westgate Dental Clinic Limited | Health & social care | 2007 |
| Westgate Tdmp Holding Limited | Health & social care | 2023 |
| Westover Automotive Limited | Extraterritorial | 2019 |
| Westover Group Limited | Professional & scientific | 2001 |
| Westwood Artificial Intelligence Ltd | Information & communication | 2021 |
| Wetanda Limited | Other services | 2014 |
| Wevagroup Ltd | Information & communication | 2007 |
| Whaddon Business Park Management Company Limited | Households | 1988 |
| Wheble Properties Ltd | Real estate | 2022 |
| Wheeler Design Ltd | Professional & scientific | 2020 |
| Wheelers Connect Limited | Transport & logistics | 2010 |
| Wheelers Travel Limited | Transport & logistics | 2002 |
| Wheelers Vehicle Solutions Limited | Real estate | 2020 |
| Whistling FIG Limited | Professional & scientific | 2024 |
| Whitaker & Co Kitchens Limited | Construction | 2021 |
| Whitbourn Associates Limited | Wholesale & retail | 2015 |
| Whitchurch Service & Repairs Limited | Wholesale & retail | 2012 |
| White & Bowker (Nominees) Limited | Extraterritorial | 1995 |
| White & Gray Architecture Design Develop Ltd | Professional & scientific | 2013 |
| White Dragon Property Limited | Real estate | 2015 |
| White Knight Recruitment Limited | Administrative & support | 1988 |
| Whitebeam Developments Ltd | Construction | 2023 |
| Whitecap Enterprises Limited | Arts & recreation | 2019 |
| Whitehaugh Court (Bishopstoke) Residents' Association Limited | Households | 1972 |
| Whiteley Local Centre Management Company Limited | Real estate | 2004 |
| Whiteparish Transport Limited | Real estate | 1988 |
| Whiting Services Ltd | Manufacturing | 2003 |
| Whizpro Ltd | Information & communication | 2010 |
| Whizz Estates LLP | | 2011 |
| Wholeheartedlead Limited | Professional & scientific | 2022 |
| Wholemark INT Ltd | Wholesale & retail | 2012 |
| WI Drive Ltd | Transport & logistics | 2022 |
| WI Rent Ltd | Real estate | 2025 |
| Wight Fire Company Limited | Other services | 2002 |
| Wild Hive Collective CIC | Education | 2022 |
| Wild Wraps Ltd | Professional & scientific | 2019 |
| Wildcat Money Ltd | Financial services | 2022 |
| Wildwood Land Group Limited | Construction | 2019 |
| Wildwood Machinery Limited | Manufacturing | 2022 |
| Wilkinson Precision Engineering Ltd | Manufacturing | 2020 |
| Will Holdings Ltd | Professional & scientific | 2020 |
| Will Rochfort Art Limited | Arts & recreation | 2023 |
| William Hatton Ltd | Other services | 2022 |
| William International Limited | Health & social care | 2021 |
| William R Selwood Ltd | Construction | 1995 |
| William Wheatley (Wickham) Limited | Wholesale & retail | 1958 |
| William Wheatley Holdings Limited | Financial services | 2003 |
| Williams & Smithells Limited | Administrative & support | 2006 |
| Williams Healthcare Limited | Health & social care | 2015 |
| Williams Mann Limited | Other services | 2006 |
| Williams Roofing Contractors (Holdings) Limited | Financial services | 2011 |
| Williams Roofing Contractors Limited | Construction | 1997 |
| Willings Services Limited | Administrative & support | 1997 |
| Willis Commercial Limited | Real estate | 2010 |
| Willow Madison Ltd | Manufacturing | 2013 |
| Willow the Wisp Ltd | Education | 2017 |
| Willowisp Limited | Real estate | 1988 |
| Wills & Co Carpentry and Joinery Ltd | Construction | 2024 |
| Wilmer House Ltd | Real estate | 2022 |
| Wilmer Retail Ltd | Wholesale & retail | 2025 |
| Wilson Healthcare Limited | Health & social care | 2005 |
| Wilson Hunt Limited | Professional & scientific | 2023 |
| Wilsons Carpentry Ltd | Manufacturing | 2020 |
| Wiltshire Electrical Ltd | Construction | 2017 |
| Winchester Building Company Ltd | Construction | 2012 |
| Winchester Curry House Ltd | Hospitality | 2023 |
| Winchester Freehold Limited | Extraterritorial | 2010 |
| Winchester Music Ltd | Education | 2025 |
| Winchester Pest Control Limited | Administrative & support | 2007 |
| Winchester Photographic Studio Limited | Professional & scientific | 2023 |