| WFS (Heating) Limited | Wholesale & retail | 2006 |
| Wharfside at Trencherfield Mill RTM Company | Households | 2023 |
| Wheatsheaf Court Limited | Households | 2005 |
| Whichemoji Limited | Information & communication | 2019 |
| Whirl Girl Events Ltd | Professional & scientific | 2025 |
| Whistle and Bark Limited | Other services | 2022 |
| Whitburn Animal Health Ltd | Agriculture & fishing | 2023 |
| Whitburn Caterers Limited | Hospitality | 2002 |
| Whitburn Church of England Academy | Education | 2010 |
| Whitburn Cottages Ltd | Real estate | 2025 |
| Whitburn Developments Limited | Real estate | 2007 |
| White Notion Holdings Ltd | Information & communication | 2020 |
| White Room Property Ltd | Real estate | 2020 |
| White Rose Golf Breaks Ltd | Administrative & support | 2021 |
| White Star Engineering Limited | Wholesale & retail | 2022 |
| White Star Travel Limited | Transport & logistics | 2015 |
| Whitebark Accountancy Ltd | Professional & scientific | 2021 |
| Whitebeam Media Ltd | Professional & scientific | 2020 |
| Whitehill Strategic Wealth Limited | Real estate | 2015 |
| Whitewaters Ltd | Construction | 2006 |
| Whitfield Haulage and Recovery Ltd | Transport & logistics | 2024 |
| Wholesale by Beth Limited | Wholesale & retail | 2025 |
| Whorlton Holdings Ltd | Real estate | 2018 |
| Whorlton Pods Limited | Hospitality | 2021 |
| WHS Builders Limited | Construction | 2020 |
| WHY EYE Photography Limited | Professional & scientific | 2008 |
| Wickens Pipefitting Services Limited | Construction | 2014 |
| Wigham J Ltd | Professional & scientific | 2023 |
| Wigham Limited | Construction | 2023 |
| Wild Club CIC | Health & social care | 2025 |
| Wild Fire City Ltd | Hospitality | 2026 |
| Wild Fire Pizza (Sunderland) Ltd | Hospitality | 2023 |
| Wild North Photo Ltd | Professional & scientific | 2024 |
| Wilde Lift Services Limited | Manufacturing | 2025 |
| Wildfox Day Nurseries Ltd | Health & social care | 2024 |
| William Forbes Limited | Financial services | 2014 |
| Willo Training Ltd | Administrative & support | 2021 |
| Willow Farm Courtyard Management Limited | Households | 2024 |
| Willow Tree Property Group Limited | Real estate | 2016 |
| Willowbank Publishing Limited | Information & communication | 2021 |
| Willows Sunderland Ltd | Hospitality | 2025 |
| Wilson Associates Ltd | Professional & scientific | 2025 |
| Wilson's Convenience Stores Limited | Wholesale & retail | 2013 |
| WILSY1 Ltd | Professional & scientific | 2023 |
| WILSY1 Property Ltd | Real estate | 2025 |
| Wilver Properties Limited | Real estate | 2020 |
| Wind Planning Ltd | Construction | 2013 |
| Wind Turbine Solutions Ltd | Construction | 2021 |
| Window and Door Repairs NE Ltd | Construction | 2025 |
| Windowsnearme Limited | Construction | 2025 |
| Wink Holdings (NE) Ltd | Professional & scientific | 2023 |
| Wink Lash Store Ltd | Wholesale & retail | 2021 |
| Winnz Limited | Health & social care | 2026 |
| Winsims Limited | Information & communication | 2016 |
| Winter Industries Limited | Information & communication | 2013 |
| Wire Rope Solutions Ltd | Professional & scientific | 2025 |
| Wise Academies | Education | 2011 |
| Wise MEN SAY Media Limited | Information & communication | 2025 |
| Wishart Mortgage Solutions Limited | Financial services | 2020 |
| WLH Group Ltd | Transport & logistics | 2025 |
| WMB (NE) Ltd | Wholesale & retail | 2015 |
| WMW Services Limited | Construction | 2016 |
| Woburn Bathrooms Ltd | Construction | 2026 |
| Women's Community Boutique CIC | Wholesale & retail | 2022 |
| Womenpause NOT Menopause C.I.C. | Wholesale & retail | 2025 |
| Wonderful Wigs Global Ltd | Professional & scientific | 2023 |
| Wonky Community CIC | Administrative & support | 2024 |
| Wood Finishers Limited | Real estate | 2026 |
| Woodcraft Studio Ltd | Wholesale & retail | 2025 |
| Woodlands Grove Estate Limited | Households | 2018 |
| Woodlands Healthcare Limited | Professional & scientific | 2020 |
| Woodlea Services Ltd | Administrative & support | 2022 |
| Woods Lettings Ltd | Real estate | 2026 |
| Woodship Ltd | Administrative & support | 2020 |
| Woodside (Sunderland) Limited | Households | 2006 |
| Woodside Farm Milk Limited | Wholesale & retail | 2015 |
| Woodstone Property Solutions Limited | Construction | 2012 |
| Woodvale Properties Limited | Construction | 2013 |
| Wooe Studios Ltd | Professional & scientific | 2025 |
| Work Strata Group Limited | Education | 2025 |
| Workinpixls Ltd. | Information & communication | 2014 |
| Workprove Limited | Information & communication | 2013 |
| World Alternative Education Limited | Education | 2016 |
| World Autism Organisation Limited | Other services | 2024 |
| Worrall Logistics Ltd | Transport & logistics | 2025 |
| Wouldhave Properties Limited | Real estate | 1965 |
| Wounded Highlanders CIC | Arts & recreation | 2021 |
| WPB Asset Management Limited | Financial services | 2008 |
| WPB NRG Services Limited | Wholesale & retail | 2025 |
| Wrap & Renew Ltd | Professional & scientific | 2021 |
| Wrap and Renew Academy Ltd | Education | 2023 |
| Wrapitup (Sunderland) Ltd | Hospitality | 2019 |
| Wrexham Shropshire & Marylebone Railway Company Limited | Transport & logistics | 2006 |
| Wright Access (NE) Ltd | Construction | 2026 |
| Wright Advice 4 U Limited | Financial services | 2019 |
| Wright Retrofit Assessments Ltd | Administrative & support | 2025 |
| WSI (Written Schemes & Inspections) Ltd | Professional & scientific | 2020 |
| Wsmr (Holdings) Limited | Transport & logistics | 2006 |
| WVH Consultancy Ltd | Construction | 2017 |
| X Chng Ltd | Health & social care | 2025 |