| Wg-Gt Property Ltd | Real estate | 2019 |
| Wharton Construction Limited | Construction | 1985 |
| What IF NOW Ltd | Professional & scientific | 2026 |
| Whatmore Properties Ltd | Real estate | 2017 |
| WHB Contractors Ltd | Administrative & support | 2021 |
| Wheeldon Corporate Services Limited | Administrative & support | 2025 |
| Wheeldon Property Ltd | Real estate | 2026 |
| Whessoe Engineering Limited | Professional & scientific | 2007 |
| Whessoe Road Aggregates Ltd | Construction | 2025 |
| Whessoe Road Auto Care Limited | Wholesale & retail | 2018 |
| Whessoe Road Deliveries Ltd | Transport & logistics | 2026 |
| Whik Hair Limited | Other services | 2013 |
| Whimsickal Ltd | Wholesale & retail | 2020 |
| White Feather Kitchen Design Ltd. | Construction | 2014 |
| White Rock Retail Ltd | Wholesale & retail | 2025 |
| White Rose Designer Landscaping Ltd | Administrative & support | 2025 |
| White Secret Aesthetics Ltd | Other services | 2026 |
| Whitebark Properties Limited | Real estate | 2019 |
| Whitehouse Funeral Service Limited | Other services | 2009 |
| Whitfield Electrical Contractors Limited | Construction | 2022 |
| Whittaker Project Management Limited | Construction | 2017 |
| Whitworth Park (Spennymoor) Limited | Households | 2007 |
| Who’S Walking WHO Ltd | Education | 2021 |
| WHY NOT? Nails Limited | Other services | 2019 |
| Whymar Limited | Real estate | 2002 |
| Widn Limited | Professional & scientific | 2023 |
| Wiga Trans Ltd | Transport & logistics | 2022 |
| Wildair (Tree Maintenance) Limited | Agriculture & fishing | 2015 |
| Will to Finish (WTF) Limited | Wholesale & retail | 2026 |
| Willans Joinery Ltd | Construction | 2018 |
| William Ruby JJJ Limited | Health & social care | 2021 |
| Willis Aviation Services Limited | Transport & logistics | 2022 |
| Willis Sustainable Fuels (UK) Limited | Transport & logistics | 2022 |
| Willow Triumph Ltd | Wholesale & retail | 2011 |
| Wilson and Co (Darlington) Ltd | Wholesale & retail | 2025 |
| Wilted Rose Ltd | Manufacturing | 2025 |
| Wimpenny Estates Limited | Construction | 2007 |
| Win-A Medical Ltd | Health & social care | 2025 |
| Windows Cleaned Today Ltd | Administrative & support | 2019 |
| Winnard Medical Services Ltd | Health & social care | 2011 |
| Winston and Porter Ltd | Manufacturing | 2012 |
| Winston Millennium Green Limited | Arts & recreation | 2022 |
| Winston Wilds Ltd | Manufacturing | 2010 |
| Winters Property Solutions Ltd | Real estate | 2024 |
| Wired Electrical North East Ltd | Construction | 2023 |
| Wisdom Engineering Ltd | Professional & scientific | 2012 |
| Wise Electrical Solutions Ltd | Construction | 2023 |
| Wise OWL Property Ltd | Real estate | 2013 |
| Wise OWL Property Training Ltd | Real estate | 2016 |
| Wiseman Group Ltd | Other services | 2018 |
| Witton Sporting Limited | Agriculture & fishing | 2017 |
| Wknf Lettings Ltd | Real estate | 2024 |
| WM Maguire Limited | Extraterritorial | 2016 |
| WM. Snaith & Sons Limited | Agriculture & fishing | 1958 |
| WMP Ltd | Households | 2026 |
| Wok-Inn Express 888 Limited | Hospitality | 2026 |
| Wolver Peen Limited | Arts & recreation | 2021 |
| Wolverton Mill Management Limited | Households | 1999 |
| Women's Enterprise UK Ltd | Education | 2015 |
| Woodland Floors Ltd | Wholesale & retail | 2019 |
| Woodlands Court (Darlington) Residents Association Limited | Households | 1999 |
| Woods Property Rentals Ltd | Real estate | 2021 |
| Woodyard Mews (York) Management Company Limited | Households | 2001 |
| Woodydog Limited | Hospitality | 2015 |
| Woodys K9 Pet Supplies Ltd | Wholesale & retail | 2020 |
| Woolly Sheep Developments Limited | Real estate | 2020 |
| Worcester Used Car Centre Limited | Wholesale & retail | 2018 |
| Word of Mouth IS a Load of Site Ltd | Information & communication | 2025 |
| Workplace Inclusion Solutions Limited | Professional & scientific | 2025 |
| Worldwide Export-Import Limited | Wholesale & retail | 2023 |
| Worswick Investments Limited | Real estate | 1955 |
| Worton Solutions Ltd | Professional & scientific | 2022 |
| Wray Construction Limited | Extraterritorial | 2021 |
| Wray Joinery Limited | Construction | 2002 |
| Wrights Office Supplies Limited | Wholesale & retail | 2000 |
| WSK Software Limited | Information & communication | 2008 |
| WT Plumbing & Heating Ltd | Construction | 2012 |
| Wtfit Ltd | Real estate | 2023 |
| Wyatt Property Ltd | Real estate | 2022 |
| WYC Corporation Ltd | Arts & recreation | 2019 |
| Wycliffe Grange Estates Limited | Construction | 2021 |
| Wynyard Pest Control Limited | Administrative & support | 2013 |
| Wyvern Fabrications Limited | Professional & scientific | 2023 |
| Wyvern Precision Ltd | Professional & scientific | 2018 |
| X-Cel Electrical & Property Solutions Ltd | Construction | 2012 |
| Xanthe Elizabeth Ltd | Professional & scientific | 2026 |
| Xavvy Limited | Information & communication | 2017 |
| XI Investments Limited | Real estate | 2024 |
| Xology Hair Studio Ltd | Other services | 2025 |
| Y & Y (NE) Ltd | Other services | 2014 |
| YA Food Services Ltd | Hospitality | 2022 |
| Yarm Fairways Limited | Wholesale & retail | 2008 |
| Yarm RD Barbers Ltd | Other services | 2026 |
| YARM48 Ltd | Hospitality | 2025 |
| Yash Techno Soft Ltd | Information & communication | 2021 |
| YE Olde Toll House (Willenhall) Limited | Hospitality | 2023 |
| Yeenom Limited | Financial services | 2013 |
| Yellow Evolution Limited | Real estate | 2015 |
| Yeshua Healthcare Ltd | Health & social care | 2020 |
| Yeshua's Holdings Ltd | Real estate | 2023 |