| Waterfall Lodge Ltd | Hospitality | 2018 |
| Waterfall Ways Limited | Hospitality | 2014 |
| Waterfront Dental Centre Ltd | Health & social care | 2009 |
| Waterfront Projects Ltd | Hospitality | 2014 |
| Waterless Limited | Wholesale & retail | 2009 |
| Waterloo Road Llanelli Limited | Real estate | 2022 |
| Watermark Financial Planning Limited | Financial services | 2009 |
| Watermark Investments(Swansea) Limited | Real estate | 2017 |
| Watermark Press Limited | Information & communication | 2020 |
| Waters Creative Limited | Other services | 2003 |
| Waters Edge Scapes Ltd | Agriculture & fishing | 2025 |
| Watershed Moment Limited | Financial services | 2020 |
| Watershield (SW) Ltd | Construction | 2009 |
| Waterside Group Limited | Professional & scientific | 1990 |
| Waterstone Estate Road Ltd | Real estate | 2016 |
| Watkin Evans Limited | Wholesale & retail | 2017 |
| Watree Homes Limited | Construction | 2017 |
| Watson at Moorcroft Limited | | 1988 |
| Watson Medical Sports Limited | Health & social care | 2019 |
| Wattcrafts Engineering Ltd | Manufacturing | 2024 |
| Wattech Limited | Professional & scientific | 2017 |
| Watts & Rees Limited | Real estate | 2024 |
| Watts Brickwork Limited | Construction | 2007 |
| Watts Rees Holdings Limited | Financial services | 2024 |
| Watwick House Management Limited | Administrative & support | 2000 |
| Waunarlwydd Galaxy Amateur Football Club CIC | Arts & recreation | 2019 |
| Waunarlwydd RFC Limited | Arts & recreation | 2016 |
| Wave Energy Ltd | Construction | 2026 |
| Wave Therapy Ltd | Education | 2019 |
| Wavy Cat Limited | Information & communication | 2023 |
| WAX Property Limited | Real estate | 2022 |
| Waxhead Clothing Ltd | Manufacturing | 2024 |
| Way Forward Counselling Services Ltd | Education | 2015 |
| Waygood Homes Services Ltd. | Real estate | 2014 |
| Waygood Real Estate Limited | Real estate | 2017 |
| Wayne Griffiths Home Refurbishments Ltd | Construction | 2023 |
| Wayne the Welder Engineering Limited | Construction | 2019 |
| Wayne's World of Waste Removal Ltd | Water & waste | 2019 |
| Ways of Working Limited | Arts & recreation | 2020 |
| WCJ Utilities Limited | Construction | 2019 |
| WCT 128 Limited | Hospitality | 2022 |
| WCU Group Ltd | Professional & scientific | 2021 |
| WCZ MK Ltd | Hospitality | 2025 |
| WD Campervan Conversions Ltd | Wholesale & retail | 2025 |
| Wdgaf RAW Ltd | Construction | 2019 |
| WDJ Assessments Limited | Professional & scientific | 2016 |
| WDW Limited | Construction | 2023 |
| WE ARE Digital Marketing Limited | Professional & scientific | 2007 |
| WE Group (South Wales) Limited | Manufacturing | 2022 |
| WE Will Clear IT Limited | Water & waste | 2014 |
| We'Re Home Ltd | Real estate | 2019 |
| Weall Cymru/Wales Limited | Professional & scientific | 2022 |
| Wealthbridge Investments Ltd | Extraterritorial | 2020 |
| Web Service Worldwide Limited | Professional & scientific | 2007 |
| WEB3DEFENCE Limited | Professional & scientific | 2025 |
| Webb Builders Limited | Wholesale & retail | 2002 |
| Webb Distribution Limited | Transport & logistics | 1996 |
| Webborn's Industrial Services Ltd | Construction | 2025 |
| Websim Ltd | Information & communication | 2018 |
| Websites UN Limited | Extraterritorial | 2023 |
| Webster Enterprises Ltd | Other services | 2019 |
| Webwording Limited | Information & communication | 1995 |
| Wecori (Trustee) EOT Limited | Professional & scientific | 2023 |
| Wecori Limited | Manufacturing | 1947 |
| Wedding Attire Limited | Wholesale & retail | 2025 |
| Weddings by Design Ltd | Hospitality | 2023 |
| Wedlake Properties Limited | Real estate | 2019 |
| Weegy Housing Limited | Construction | 2014 |
| Wehi Web Design Limited | Other services | 2017 |
| WEI Electronics Limited | Wholesale & retail | 2016 |
| Weightman Developments Limited | Real estate | 2019 |
| Weightman's Properties Limited | Real estate | 2019 |
| Welchem 2 Limited | Wholesale & retail | 2025 |
| Welchem 3 Limited | Wholesale & retail | 2025 |
| Welchem Limited | Wholesale & retail | 1962 |
| Welchem Medical Limited | Health & social care | 2024 |
| Welchem Pharmaceuticals Wholesale Limited | Wholesale & retail | 2022 |
| Welcome Retail Ltd | Wholesale & retail | 2023 |
| Weldspec International Ltd | Construction | 2018 |
| Weldtek Fabrication Ltd | Manufacturing | 2026 |
| Welgate Freehold Limited | Households | 2016 |
| Well Impressed Ironing Services Ltd | Administrative & support | 2020 |
| Well Tied Limited | Construction | 1987 |
| Wellington Bear Property Limited | Construction | 2020 |
| Wellness Dispensary Ltd | Administrative & support | 2016 |
| Welsh Amateur Swimming Association Limited | Arts & recreation | 2007 |
| Welsh Coast Radio Limited | Information & communication | 2025 |
| Welsh Eco Lodges Ltd | Extraterritorial | 2013 |
| Welsh Farmhouse Kitchen Limited | Manufacturing | 2025 |
| Welsh Housing AID Limited | Health & social care | 1984 |
| Welsh Masters Athletics Limited | Other services | 2019 |
| Welsh Mountain Meats Limited | Manufacturing | 2025 |
| Welsh Stars Ltd | Administrative & support | 2023 |
| Welshveins Limited | Health & social care | 2025 |
| Weltec Engineering Ltd | Extraterritorial | 2010 |
| Wendover and Swansea Properties Limited | Real estate | 1998 |
| Wernbwll Ltd | Agriculture & fishing | 2019 |
| Wernllath Farm Ltd | Agriculture & fishing | 2024 |
| Wernoleu Road SPV Limited | Construction | 2025 |
| Wesley Greens Engineering Limited | Professional & scientific | 2014 |