| Vita Ristorante Limited | Hospitality | 2013 |
| Vrtize Limited | Information & communication | 2016 |
| W Design Studio Limited | Professional & scientific | 2014 |
| Warner Bros Plumbing and Heating Ltd | Construction | 2015 |
| Warner Property Solutions Ltd | Construction | 2025 |
| Warrengate Autos Ltd | Wholesale & retail | 2017 |
| Waterdells Ltd | Professional & scientific | 2023 |
| Wavecrest Systems Limited | Professional & scientific | 1992 |
| WE Estate Managment Limited | Households | 2024 |
| Websemantics Ltd | Information & communication | 2008 |
| Websters Surveyors Limited | Professional & scientific | 2013 |
| Websters Surveyors NO. 2 Ltd | Professional & scientific | 2026 |
| Weddings in Style Limited | Administrative & support | 2005 |
| Weee Reeco Limited | Financial services | 2008 |
| Weight and Measures Advice Ltd | Information & communication | 2008 |
| Welwyn Consultancy Limited | Professional & scientific | 2013 |
| Welwyn Contract Flooring Ltd | Construction | 2019 |
| Welwyn Estates Ltd | Real estate | 2021 |
| Welwyn Garden City Limited | Extraterritorial | 2019 |
| Welwyn Garden City Orchestra Productions Limited | Arts & recreation | 2019 |
| Welwyn Hall (NO. 2) Management Limited | Real estate | 1997 |
| Welwyn Hall Management Limited | Households | 1996 |
| Welwyn Homes Limited | Construction | 2021 |
| Welwyn Luxury Beauty Limited | Other services | 2026 |
| Welwyn Rugby Football Club Limited | Arts & recreation | 2010 |
| Western Marketing Limited | Information & communication | 2018 |
| Westlea Landscaping Limited | Administrative & support | 2012 |
| Wexli Academy Ltd | Education | 2018 |
| WFM Holdings LLP | | 2016 |
| WFM International Limited | Real estate | 2016 |
| Whanau Day Nursery (WGC) Limited | Financial services | 2024 |
| Wheatbutts Residents Association Limited | Households | 1993 |
| Whetstone Court Residence Association Limited | Households | 1987 |
| White IT Consulting Ltd | Information & communication | 2017 |
| White Rocks Property Limited | Real estate | 2021 |
| White Shore Consulting Ltd | Professional & scientific | 2018 |
| White Tech Consulting Limited | Professional & scientific | 2019 |
| Whitehall Scaffolding Limited | Construction | 2025 |
| Wilkinson Management Services Ltd | Professional & scientific | 2025 |
| Willow C (AL6) RTM Company Limited | Households | 2025 |
| Willow Court (1-3) RTM Company Limited | Households | 2025 |
| Willow Court (4-8) RTM Company Limited | Households | 2025 |
| Winch Close Management Company Limited | Households | 1989 |
| Witches LAB Limited | Wholesale & retail | 2014 |
| Woodmann Consulting Limited | Professional & scientific | 2019 |
| Woodmann Properties Limited | Real estate | 2019 |
| WOODSTOCK30 Limited | Real estate | 2015 |
| Worth the Earth Ltd | Extraterritorial | 2018 |
| XY Property Development Ltd | Construction | 2022 |
| Yingming Limited | Administrative & support | 2008 |
| Your Financial Assurance Ltd | Financial services | 2011 |
| Zorba IT Solutions Limited | Information & communication | 2012 |