| Winterton Park Management Company NO 3 Limited | Households | 2002 |
| Winterton Park Management Company NO 4 Limited | Households | 2003 |
| Wired Cat Media Limited | Arts & recreation | 2011 |
| Wisymore Enterprise Limited | Wholesale & retail | 2025 |
| Witchgraft Ltd | Professional & scientific | 2024 |
| WLK Northeast Ltd | Information & communication | 2024 |
| WML Lifting Ltd | Professional & scientific | 2018 |
| Woking AGE Concern | Health & social care | 2005 |
| Wolf Promotions Ltd | Wholesale & retail | 2025 |
| Wolviston Management Co. Limited | Real estate | 2003 |
| Wood Heat Limited | Construction | 2012 |
| Wood Top Limited | Financial services | 2012 |
| Wood Ventures Limited | Real estate | 1998 |
| Woodcock Engineering Design Limited | Information & communication | 1997 |
| Woodcroft Motors Ltd | Wholesale & retail | 2013 |
| Woodhouse Aesthetics Ltd | Other services | 2022 |
| Woodhouse Assets Ltd | Hospitality | 2023 |
| Woodhouse Dental Ltd | Manufacturing | 2021 |
| Woodlands Cafe & Deli Ltd | Hospitality | 2009 |
| Woodside Consultants Limited | Professional & scientific | 2025 |
| Woodside Farm at Wynyard Woodland Ltd | Hospitality | 2023 |
| Woodspray Wood Finishing Ltd | Other services | 2008 |
| Woodtrack Limited | Wholesale & retail | 2015 |
| Woof Pet Supplies Ltd | Wholesale & retail | 2025 |
| Woofles Ltd | Wholesale & retail | 2018 |
| Wooldridge Property Ltd | Real estate | 2026 |
| Work and Health Solutions Limited | Health & social care | 2013 |
| Working (UK) Solutions Limited | Health & social care | 2002 |
| Working Solutions Limited | Health & social care | 2001 |
| Workman Associates Limited | Professional & scientific | 1996 |
| World of Travel Group Limited | Administrative & support | 2025 |
| Worsall Developments Limited | Construction | 2019 |
| WPS Sedgefield Ltd | Other services | 2020 |
| Wpsl 2009 Limited | Administrative & support | 2009 |
| Wrencomm Ltd | Professional & scientific | 2024 |
| Wright Move Lettings Ltd | Real estate | 2025 |
| Writeo Limited | Professional & scientific | 2025 |
| Wrmin Aces Ltd | Wholesale & retail | 2025 |
| Wroxham Services Ltd | Professional & scientific | 2021 |
| WS Residential Services Limited | Construction | 2021 |
| WSM Traders Limited | Wholesale & retail | 2018 |
| WSP Management Ltd | Construction | 2018 |
| WT Groundworks Limited | Construction | 2019 |
| WV Engineering Ltd | Professional & scientific | 2018 |
| WW Contracts Ltd | Construction | 2018 |
| WW Electrical Inspections Ltd | Professional & scientific | 2014 |
| WWR Aluminium Ltd | Manufacturing | 2016 |
| Wyex Consultancy Ltd | Manufacturing | 2017 |
| Wynchcombe CS Ltd | Education | 2024 |
| Wynyard Motor Company Limited | Wholesale & retail | 2012 |
| Wynyard Tree Services Ltd | Administrative & support | 2022 |
| XAM Solutions Limited | Professional & scientific | 2012 |
| XG Consultancy Ltd | Information & communication | 2024 |
| XL EDM (Holdings) Limited | Professional & scientific | 2008 |
| XL Precision Technologies Limited | Manufacturing | 1998 |
| XL Travel Limited | Arts & recreation | 2002 |
| Xocs Design Ltd | Professional & scientific | 2022 |
| Xpertranker Ltd | Information & communication | 2025 |
| XRM Upskill Limited | Information & communication | 2019 |
| Xtendextensions Ltd | Other services | 2024 |
| XTRA9CE Limited | Wholesale & retail | 2022 |
| Y T Transport Ltd | Transport & logistics | 2022 |
| Yaqoob Dwellings Ltd | Real estate | 2025 |
| Yaqoob Group Ltd | Real estate | 2025 |
| Yarm & Eaglescliffe Football Club CIC | Arts & recreation | 2025 |
| Yarm Computers Limited | Information & communication | 1998 |
| Yarm Electrical Services Ltd | Manufacturing | 2026 |
| Yarm Fast Food Ltd | Hospitality | 2015 |
| Yarm Flats Limited | Households | 1965 |
| Yarm Interiors Ltd | Wholesale & retail | 2025 |
| Yarm Lane Dental Limited | Health & social care | 2026 |
| Yarm Property Maintenance Ltd | Construction | 2019 |
| Yarm Property Management Limited | Real estate | 2017 |
| Yarm Roofing & Building Ltd | Construction | 2024 |
| Yarm Services Limited | Professional & scientific | 2012 |
| Yarm Taxis Ltd | Extraterritorial | 2022 |
| Yarm Window Cleaning Ltd | Administrative & support | 2023 |
| Yarm Wolves CIC | Arts & recreation | 2022 |
| Yass Properties Ltd | Real estate | 2024 |
| YAZ Enterprises Limited | Wholesale & retail | 2020 |
| YB Solutions Ltd | Construction | 2025 |
| YC Cabling Limited | Construction | 2023 |
| Yeadon Properties Ltd | Real estate | 2020 |
| Yedroc Limited | Manufacturing | 2023 |
| Yefia Foods Limited | Wholesale & retail | 2025 |
| Yellow Box Marketing Limited | Information & communication | 2019 |
| Yellow-Stone Solutions Ltd | Administrative & support | 2025 |
| Yendalls Engineering Ltd | Professional & scientific | 2012 |
| YFT Consult Ltd | Financial services | 2016 |
| YHC Ltd | Hospitality | 2019 |
| YI Property Ltd | Real estate | 2020 |
| YM Smile Ltd | Health & social care | 2025 |
| Yogiwhale Limited | Administrative & support | 2024 |
| Yonamy Ltd | Transport & logistics | 2023 |
| York Bearings and Transmissions Limited | Wholesale & retail | 2003 |
| York Homes Limited | Construction | 2016 |
| Yorkshire Bathrooms and Kitchens Limited | Wholesale & retail | 2005 |
| Yorkshire Construction Contractors Limited | Construction | 2004 |
| Yorkshire Driveways & Building UK Ltd | Construction | 2025 |
| Young Inspection Services Ltd | Construction | 2019 |