| Wessex Property Holdings Limited | Financial services | 2025 |
| Wessex Property Solutions Ltd | Real estate | 2020 |
| Wessex Psychological Services Ltd | Health & social care | 2024 |
| Wessex Structural Engineers Limited | Professional & scientific | 2025 |
| Wessex Trailer Rental Limited | Administrative & support | 2020 |
| West Lavant Barns Management Company Limited | Households | 2013 |
| West Lodge Estates Limited | Agriculture & fishing | 2010 |
| WEST4PROPERTY Ltd | Information & communication | 2014 |
| Westbury Energy Consulting Ltd | Professional & scientific | 2014 |
| Western Farm Limited | Agriculture & fishing | 1997 |
| Western Marketing Management Limited | Professional & scientific | 2003 |
| Western Oceanic Consultants Limited | Professional & scientific | 2013 |
| Westerwood Properties Limited | Real estate | 1998 |
| Westgate House Management Company (Winchester) Limited | Hospitality | 1999 |
| Westgate Mews (Chichester) Management Company Limited | Households | 2004 |
| Westgate Wealth Management Ltd | Administrative & support | 2015 |
| Westhill Farming Limited | Agriculture & fishing | 2010 |
| Westlecot Holme Management Company Limited | Households | 2005 |
| Westley Building Contractors Limited | Construction | 2009 |
| Westley Close 1971 Limited | Extraterritorial | 2014 |
| Westley Developments Limited | Construction | 2025 |
| Westley Enterprises Limited | Hospitality | 1987 |
| Westown Holdings Limited | Professional & scientific | 2018 |
| Westsmith Ltd | Information & communication | 2019 |
| Weyborne Limited | Agriculture & fishing | 2017 |
| WFC Drayton Farming Limited | Agriculture & fishing | 2001 |
| WH23 Limited | Professional & scientific | 2020 |
| Whaddon Site Services Ltd | Construction | 2019 |
| Wharf House Apartments Management Limited | Households | 2005 |
| Wharf House Properties Limited | Real estate | 2016 |
| Wheeler Industrial Worldwide Limited | Mining & quarrying | 2015 |
| Wheels & Tyres Direct Limited | Extraterritorial | 2002 |
| Whipround Ltd | Information & communication | 2025 |
| White Bulls Automation Ltd | Manufacturing | 2026 |
| White Gates Consultancy Ltd | Professional & scientific | 2024 |
| White Horse Heritage Ltd | Construction | 2026 |
| White One Sugar Limited | Information & communication | 2014 |
| White Swan Court Residents Association Limited | Hospitality | 1984 |
| White Works Limited | Professional & scientific | 2002 |
| Whitebox Creative Limited | Administrative & support | 2013 |
| Whitefoot Contracting Ltd | Administrative & support | 2019 |
| Whitehaven Homes Limited | Real estate | 2017 |
| Whitehouse Printing Ltd | Manufacturing | 2019 |
| Whitwam Holdings Limited | Real estate | 1978 |
| Whitwam Limited | Administrative & support | 2011 |
| Whyke Court Residents Limited | Households | 2012 |
| Whyte Homes Limited | Wholesale & retail | 2014 |
| Whyte Music Ltd | Professional & scientific | 2011 |
| Wickham Fields Management Company Limited | Households | 2025 |
| Wilco Limited | Real estate | 2024 |
| Wild Capital Limited | Real estate | 2023 |
| Wild in White Studio Limited | Wholesale & retail | 2025 |
| Wild Lady Limited | Agriculture & fishing | 2025 |
| Wild Wheels Limited | Professional & scientific | 2018 |
| Wild Wonderful World Ltd | Administrative & support | 2019 |
| Wilderness Pictures Ltd | Information & communication | 2022 |
| Wildmoor Estates Limited | Real estate | 2011 |
| Wildseed Technologies Ltd | Information & communication | 2022 |
| Wildtex Limited | Information & communication | 2016 |
| Wilflo Maritime Consultancy Limited | Professional & scientific | 2022 |
| Will Bailey Online Ltd | Information & communication | 2016 |
| Will Houghton Ltd | Professional & scientific | 2019 |
| Willett Consulting Limited | Professional & scientific | 2025 |
| William Place Management Company Limited | Real estate | 2016 |
| Williams GEO Consultants Limited | Professional & scientific | 2023 |
| Willow Avon (Small Works) Limited | Wholesale & retail | 1987 |
| Willowstream Consulting Ltd | Professional & scientific | 2021 |
| Willowvale Green Limited | Real estate | 2020 |
| Willpower Brands Limited | Professional & scientific | 2007 |
| Wilton Contracting Ltd | Construction | 2020 |
| Wilton Holdings Limited | Extraterritorial | 2005 |
| Wilton Property Management (Burley) Limited | Extraterritorial | 1983 |
| Wims Holdings Limited | Real estate | 2022 |
| Wims Limited | Financial services | 1999 |
| WIN College Transfers Ltd | Transport & logistics | 2025 |
| Win-Fitt Ltd | Arts & recreation | 2025 |
| Wincentral Travel Ltd | Transport & logistics | 2024 |
| Winchester Action on Climate Change Ltd | Other services | 2012 |
| Winchester Anaesthetic Services Limited | Health & social care | 2013 |
| Winchester Bakery Limited | Manufacturing | 2020 |
| Winchester Barbers SO23 Limited | Other services | 2025 |
| Winchester Books Festival CIC | Information & communication | 2022 |
| Winchester Bourne Limited | Professional & scientific | 1993 |
| Winchester Business School Limited | Education | 2017 |
| Winchester Capital Cars Ltd. | Transport & logistics | 2022 |
| Winchester Capital Partners Limited | Financial services | 2015 |
| Winchester Carpentry & Joinery Limited | Construction | 2014 |
| Winchester Cars Ltd | Transport & logistics | 2025 |
| Winchester Catch Fish and Chips Partnership Ltd | Hospitality | 2019 |
| Winchester Cathedral Enterprises Limited | Wholesale & retail | 1987 |
| Winchester Churches Nightshelter | Health & social care | 2000 |
| Winchester City 1884 Trading Co Ltd | Arts & recreation | 2022 |
| Winchester City Centre Partnership Limited | Other services | 1997 |
| Winchester City FC C.I.C. | Education | 2023 |
| Winchester Coffee Roasters Ltd | Wholesale & retail | 2014 |
| Winchester Coffee School Ltd | Hospitality | 2018 |
| Winchester College Sports Ltd | Arts & recreation | 2018 |
| Winchester College Trading Company Limited | Hospitality | 1991 |
| Winchester Cookery School Ltd | Wholesale & retail | 2026 |
| Winchester Design & Build Ltd | Professional & scientific | 2024 |