| Walters & Co Advisory Group Ltd | Professional & scientific | 2026 |
| Wang 328 Limited | Hospitality | 2020 |
| Warmaglaze Home Improvements Limited | Manufacturing | 1998 |
| Waterfall Lettings Ltd | Real estate | 2024 |
| Waters Edge Livery Limited | Arts & recreation | 2004 |
| Watkins Holdings (Glynneath) Ltd | Financial services | 2025 |
| Watras Holdings Limited | Financial services | 2019 |
| Waunceirch Estates Limited | Real estate | 2016 |
| Waves Industrial Cleaning Ltd | Administrative & support | 2025 |
| Way OUT Pictures Limited | Information & communication | 2021 |
| Wayne's Windows and Doors Ltd | Manufacturing | 2026 |
| WB Phillips Metals Ltd | Wholesale & retail | 2018 |
| WBF Solutions Ltd | Information & communication | 2026 |
| WBV Limited | Professional & scientific | 2010 |
| WBV Nominees Limited | Extraterritorial | 2010 |
| WE Store Swansea Limited | Construction | 2018 |
| Weddings by Kate Ltd | Hospitality | 2019 |
| Welsh Words Ltd | Education | 2024 |
| Western Takeaway Limited | Hospitality | 2021 |
| Whispers Equine Ltd | Health & social care | 2022 |
| Whispers Therapeutic Services CIC | Agriculture & fishing | 2024 |
| White Gate Properties Limited | Transport & logistics | 2014 |
| White Island Fashion Limited | Wholesale & retail | 2012 |
| White Rock Property Care Limited | Construction | 2010 |
| White Rock Services (South Wales) Ltd | Construction | 2014 |
| White Sheep Property Limited | Households | 2022 |
| Whitney Construction Consulting Ltd | Professional & scientific | 2024 |
| Whitney Planning Services Ltd | Professional & scientific | 2019 |
| Will Writing Solutions Limited | Other services | 2023 |
| Williams Bluebell Properties Limited | Real estate | 2026 |
| Williams Contractor Services Ltd | Professional & scientific | 2024 |
| Williams General Limited | Professional & scientific | 2018 |
| Williams Landscaping Services Ltd | Administrative & support | 2025 |
| Willy Lettings Limited | Real estate | 2020 |
| Window Trade Centre Limited | Manufacturing | 2022 |
| Windso Food Ltd | Hospitality | 2025 |
| WJ Roofline Ltd | Construction | 2021 |
| WLS Mortgage Advice Limited | Financial services | 2025 |
| WOK LIN Limited | Hospitality | 2023 |
| Woodlands Childcare Centre Limited | Health & social care | 2019 |
| Woodside Education Services Ltd | Education | 2017 |
| Woolfe Carpentry Limited | Construction | 2025 |
| Worcesters Properties Ltd | Real estate | 2025 |
| World Rugby Museum Limited | Arts & recreation | 2008 |
| Wrighty Property Ltd | Construction | 2025 |
| WRS Repairs & Maintenance Ltd | Construction | 2026 |
| XRD Ltd | Wholesale & retail | 2025 |
| XVC Campers Limited | Manufacturing | 2021 |
| Yang 168 Limited | Hospitality | 2026 |
| Ynysdawley Estates Limited | Agriculture & fishing | 2006 |
| Ynysygerwn Community Sports and Social Club Ltd | Hospitality | 2026 |
| Yoga Place Abertawe Limited | Arts & recreation | 2015 |
| Ysgol Y Goedwig Llansawel CIC | Health & social care | 2023 |
| Zafran Foods Ltd | Hospitality | 2026 |
| Zeezah Ltd | Hospitality | 2026 |
| Zero Market Inc Limited | Wholesale & retail | 2025 |
| Zion Community Care Limited | Health & social care | 2022 |
| ZIP Solutions UK Ltd | Information & communication | 2024 |
| ZSR Leisure Limited | Hospitality | 2014 |