| Waterworth Logistics Limited | Transport & logistics | 2010 |
| WCS Search & Advisory Ltd | Administrative & support | 2024 |
| WE Frame Anything Ltd | Manufacturing | 2025 |
| Wear 1 Care Ltd | Health & social care | 2015 |
| Wear Valley Homes Ltd | Real estate | 2018 |
| Wear Valley Properties Ltd | Real estate | 2025 |
| Weardale Cheese Limited | Manufacturing | 2013 |
| Weardale Community Partnership Ltd | Professional & scientific | 2005 |
| Weardale Community Transport Limited | Transport & logistics | 2005 |
| Weardale EAR Care Ltd | Health & social care | 2023 |
| Weardale Flooring Limited | Wholesale & retail | 2020 |
| Weardale Motor Services Limited | Transport & logistics | 1961 |
| Weardale Outdoor Adventures Ltd | Arts & recreation | 2022 |
| Weardale Park Cottages Management Company Ltd. | Real estate | 2002 |
| Weardale Projects Support Ltd | Wholesale & retail | 2023 |
| Weardale Property Agency Ltd | Real estate | 2023 |
| Weardale Racing Ltd | Wholesale & retail | 2013 |
| Weardale Railway Limited | Arts & recreation | 2020 |
| Weardale Recruitment Ltd | Administrative & support | 2014 |
| Weardale Renewable Energy CIC | Energy | 2022 |
| Weardale Roofing Limited | Construction | 2002 |
| Weardale Together Community Interest Company | Hospitality | 2021 |
| Weardale Wordfest CIC | Arts & recreation | 2025 |
| Welch Surfacing Ltd | Construction | 2026 |
| Welcome & Co UK Limited | Wholesale & retail | 2020 |
| Welcome & Sons UK Limited | Wholesale & retail | 2022 |
| Welcome Capital UK Limited | Real estate | 2025 |
| Weldx Ltd | Manufacturing | 2019 |
| Wesley Holland Limited | Wholesale & retail | 1999 |
| West Aucklands Foods Ltd | Hospitality | 2026 |
| West Blackdene Management CIC | Households | 2024 |
| West Park Day Nursery Limited | Health & social care | 2005 |
| West Park Holdings Darlington Ltd | Financial services | 2025 |
| Westcott Home Improvements Limited | Construction | 2003 |
| Westerton Caravan Storage Limited | Other services | 2015 |
| Westerton Consulting Ltd | Professional & scientific | 2022 |
| Westerton Industrial Estate Limited | Real estate | 2013 |
| Westgarth Capital Limited | Real estate | 2020 |
| Westgate Facilities Ltd | Construction | 2018 |
| Westwinds Marketing Ltd | Professional & scientific | 2021 |
| Westwinds Property Services Limited | Administrative & support | 2019 |
| WET Tortoise and FOX Limited | Professional & scientific | 2018 |
| WG Pybourne & Sons Limited | Construction | 2012 |
| What's the Story Ltd | Information & communication | 2025 |
| WHG South Ltd | Hospitality | 2023 |
| Whimsical Nook Ltd | Real estate | 2023 |
| Whinney Fields Management Company Limited | Households | 2020 |
| White Lodge (Swanland) Management Company Limited | Households | 2017 |
| Whitehouse Property Services Limited | Real estate | 2020 |
| Wiggle Waggle Limited | Agriculture & fishing | 2014 |
| Wigley Enterprises Limited | Information & communication | 2024 |
| Wild Rise Bakes Ltd | Manufacturing | 2025 |
| Wildfox Consulting Ltd | Professional & scientific | 2025 |
| Will Woodhouse Ltd | Professional & scientific | 2026 |
| William Love,Limited | Agriculture & fishing | 1910 |
| Willow Lane (Beverley) Management Company Limited | Households | 2020 |
| Willowbrook Manor Management Company Limited | Households | 2015 |
| Wilson Crafted Interiors Ltd | Wholesale & retail | 2025 |
| Wilson's Property Ltd | Real estate | 2024 |
| Witton Management Consulting Limited | Administrative & support | 2025 |
| Witton Park Community Buses Ltd | Transport & logistics | 2024 |
| Witton Park Tasc Football CIC | Education | 2023 |
| Witton Residential Limited | Real estate | 2018 |
| Witton Tower Gardens Residents Limited | Households | 2011 |
| Wlcx Developments Ltd | Construction | 2024 |
| Wm.Allison & Sons Limited | Agriculture & fishing | 1954 |
| WMC Consultancy & Management Ltd | Professional & scientific | 2026 |
| Wolfpack Adventures CIC | Arts & recreation | 2025 |
| Wolsingham Motor Co. Limited | Transport & logistics | 1977 |
| Wolsingham Park Farms Limited | Agriculture & fishing | 1965 |
| Wolsingham Steelworks CIC | Arts & recreation | 2022 |
| Wonderful Whippy Limited | Hospitality | 2016 |
| Wood House Property Services Limited | Real estate | 2022 |
| Woodberry Grange Management Company Limited | Households | 2011 |
| Woodbury International Limited | Professional & scientific | 2016 |
| Woodcroft Holidays Limited | Hospitality | 2023 |
| Woodfine Locum Ltd | Wholesale & retail | 2025 |
| Woodhall Grange Management Company Limited | Households | 2013 |
| Woodhall View (Pudsey) Management Company Limited | Real estate | 2019 |
| Woodhead Homes Limited | Real estate | 2024 |
| Woodhouse Grange Limited | Real estate | 2024 |
| Woodlands Walk (Branton) Management Company Limited | Households | 2013 |
| Woodrocks Services Ltd | Education | 2025 |
| Woolwich Contemporary Print Fair Limited | Administrative & support | 2017 |
| Workmade Futures CIC | Administrative & support | 2025 |
| World of Iron Ltd | Wholesale & retail | 2008 |
| WR Commercials Ltd | Wholesale & retail | 2022 |
| WR Groundworks Ltd | Construction | 2022 |
| Wrath Commercials Limited | Wholesale & retail | 2020 |
| Wright Professional Solutions (Durham) Ltd | Administrative & support | 2012 |
| Wright Professional Solutions Limited | Professional & scientific | 2003 |
| WT & HT Limited | Hospitality | 2024 |
| Wtjp Ltd | Hospitality | 2019 |
| WV Associates Limited | Manufacturing | 1984 |
| Wyrd Herbs Limited | Wholesale & retail | 2023 |
| XDF CIC | Other services | 2022 |
| XTN Ltd | Wholesale & retail | 2025 |
| Xtrasonic Media Ltd | Information & communication | 2019 |
| Y R M Metal Solutions Limited | Manufacturing | 2008 |
| Y& a Food Ltd | Hospitality | 2024 |