| Whitewater Finance Limited | Financial services | 2003 |
| Whitewater Potatoes Limited | Agriculture & fishing | 1987 |
| Whittome Limited | Real estate | 2002 |
| Widecontact Limited | Administrative & support | 1987 |
| Wifi Connect Limited | Information & communication | 2005 |
| William Medcalf Limited | Wholesale & retail | 2004 |
| William Street Services Limited | Wholesale & retail | 2003 |
| Willow Construction Services Limited | Construction | 2002 |
| Willow Consultancy Limited | Information & communication | 1997 |
| Willowgate Limited | Real estate | 2001 |
| Willowsign Limited | Real estate | 1982 |
| Willson Mccowen Construction Ltd | Construction | 2007 |
| Wilsco 237 Limited | Real estate | 1997 |
| Wilson Designer Homes Limited | Construction | 2002 |
| Wilson Exclusive Homes Limited | Construction | 2001 |
| Wilson Homes Limited | Construction | 2002 |
| Winchester Flat Management Limited | Real estate | 2003 |
| Winchester Office Supplies Ltd | Professional & scientific | 2005 |
| Windmill Information Systems Limited | Information & communication | 2007 |
| Windsor Court (Swindon) Management Company Limited | Households | 2004 |
| Wine Matters Limited | Administrative & support | 2004 |
| Wing Global Trading Limited | Wholesale & retail | 1996 |
| Wingate Electrical PLC | Construction | 1973 |
| Wingate Limited | Professional & scientific | 2004 |
| Winsor Property Company Limited | Real estate | 1972 |
| Wireless Measurement Limited | Manufacturing | 2004 |
| Wise Electricals Ltd | Professional & scientific | 2007 |
| Wiseman Enterprises Limited | Information & communication | 1997 |
| WIT Press Limited | Information & communication | 2003 |
| With Added Ltd | Information & communication | 2007 |
| With OUR Complements Ltd. | Wholesale & retail | 1999 |
| Wizard on Wheels (Fareham) Limited | Wholesale & retail | 2005 |
| Woodcroft Pre-School and Wraparound Care | Education | 2006 |
| Wooden Badger Ltd | Real estate | 2001 |
| Wooden.Co.Uk Ltd | Wholesale & retail | 2003 |
| Woodlands & Hill Brow Limited | Health & social care | 2000 |
| Woodxi Limited | Information & communication | 2025 |
| Workplace Holdings Ltd | Financial services | 2020 |
| World Freight Group (1992) Ltd | Transport & logistics | 2025 |
| Wormcity Ltd | Wholesale & retail | 2007 |
| Wowmedia Limited | Professional & scientific | 2006 |
| Write-Enabled Limited | Information & communication | 1997 |
| Wuxian Limited | Other services | 2005 |
| Xcoy Limited | | 1985 |
| XL Projects Limited | Extraterritorial | 2005 |
| Xperience Associates Limited | Professional & scientific | 2006 |
| Yacht Haven International Limited | Professional & scientific | 1979 |
| Yacht Haven Management Limited | Arts & recreation | 1991 |
| Yacht Haven Quay Limited | Arts & recreation | 2005 |
| Yacht Havens Group Limited | Professional & scientific | 1988 |
| Yacht International Ltd | Manufacturing | 2019 |
| Yash Aaron Ltd | Real estate | 2025 |
| Yateley Building Services Limited | Construction | 2000 |
| Yateley Drawing Service Limited | Professional & scientific | 2007 |
| YBC Domestic Ltd | Administrative & support | 2025 |
| YBC Holdings Ltd | Financial services | 2019 |
| Yellow Feather Ltd | Information & communication | 1997 |
| Yellow Strawberry Hairdressing Limited | Other services | 2007 |
| Ylenoy Ltd | Wholesale & retail | 2026 |
| Ymca Cornerstone Properties Ltd. | Professional & scientific | 2001 |
| Young Forces Limited | Wholesale & retail | 2006 |
| Young George Jewellers Limited | Other services | 2003 |
| Your Financial Future Limited | Financial services | 2006 |
| Your Network UK Limited | Other services | 2006 |
| Zahtech Limited | Information & communication | 2020 |
| ZAK Court Limited | Real estate | 2005 |
| Zensia Ltd | Health & social care | 2025 |
| Zero-One LP | | 2022 |
| Zoom With a View Limited | Information & communication | 2004 |
| ZYX UK Publishing Limited | Information & communication | 1992 |