| West Coast Knitwear Limited | Wholesale & retail | 2023 |
| West END Commercial Units Ltd | Real estate | 2022 |
| West Nine Developments Limited | Construction | 2006 |
| West Stock Ltd | Wholesale & retail | 2005 |
| West-Bake UK Limited | Manufacturing | 2020 |
| Westco (N.I.) Limited | Transport & logistics | 2019 |
| Westdove Limited | Wholesale & retail | 2011 |
| Western EYE Clinic Ltd | Health & social care | 2022 |
| Western Laser Clinic | Health & social care | 2014 |
| Western Seeds Ireland Limited | Wholesale & retail | 2022 |
| Westexa Systems L.P. | | 2017 |
| Westfair Complex L.P. | | 2017 |
| Westmile Invest L.P. | | 2016 |
| Westpack UK Limited | Other services | 2016 |
| Westrup Consulting Limited | Health & social care | 2011 |
| Westview Horizons Ltd | Financial services | 2026 |
| Wexmar Administration Services Ltd | Administrative & support | 2019 |
| Whin Bush Limited | Wholesale & retail | 2019 |
| White & Mills Ltd | Information & communication | 2025 |
| White Blossom Bridal Ltd | Wholesale & retail | 2019 |
| White Mountain Water Coolers (N.I.) Ltd | Wholesale & retail | 2020 |
| White Water Property Consultants Limited | Real estate | 2025 |
| Whitegates Community Business Limited | Real estate | 1993 |
| Whitehall Mews Management Company Limited | Households | 2016 |
| Whitehill House Limited | Agriculture & fishing | 2014 |
| Whiterock Pet Crematorium Ltd | Professional & scientific | 2026 |
| Whiterock Physio and Pilates Limited | Health & social care | 2025 |
| Whiteside Coffee Ltd | Hospitality | 2024 |
| Whiteside Consulting Ltd | Professional & scientific | 2024 |
| Whitewater SC Consulting Ltd | Professional & scientific | 2026 |
| Wholesale Home Fuels Ltd | Wholesale & retail | 2013 |
| Wholesale INK Limited | Wholesale & retail | 2011 |
| Wideland Export L.P. | | 2017 |
| Wild Coastal Ltd | Administrative & support | 2021 |
| Wilden Construction Services Limited | Construction | 2013 |
| Wildflower Cafe Limited | Hospitality | 2023 |
| William Bird (N.I.) Limited | Arts & recreation | 1989 |
| William Mccombe & SON Ltd | Other services | 2009 |
| William Rogers Construction Ltd | Construction | 2018 |
| Willow EVE Ltd. | Construction | 2017 |
| Willow Tree Wholesale Ltd | Manufacturing | 2024 |
| Willowfield Common Management Company Limited | Households | 2006 |
| Wilson Farms Limited | Agriculture & fishing | 2010 |
| Wilson Thompson Limited | Financial services | 2025 |
| Wilson Wood Works Ltd | Construction | 2014 |
| Windrise Renewables Limited | Energy | 2024 |
| Windsor Hill Physiotherapy Clinic Ltd | Health & social care | 2005 |
| Windy Ridge Studio Limited | Information & communication | 2014 |
| Winebrook Limited | Real estate | 2016 |
| Winestopper Ltd | Hospitality | 2016 |
| Wings Pole Studio Ltd | Arts & recreation | 2020 |
| Wingtech Solutions Limited | Information & communication | 2016 |
| Winmark Trade L.P. | | 2017 |
| Winters Management Group Ltd | Wholesale & retail | 2019 |
| Wireless Cctv (Northern Ireland) Limited | Manufacturing | 2019 |
| WM Carpentry Limited | Construction | 2018 |
| WM Heslip Ltd | Wholesale & retail | 2013 |
| WMC Concrete Ltd | Construction | 2025 |
| WNS Contracts Ltd | Construction | 2024 |
| Woburn Developments Ltd | Construction | 2018 |
| Woburn House (Millisle) Limited | Real estate | 2018 |
| Woburn Millisle Management Company Limited | Households | 2019 |
| Wolfhound Bonded Ltd | Transport & logistics | 2023 |
| Women's AID Armagh Down Ltd | Other services | 1996 |
| Wood and Things Ltd | Manufacturing | 2022 |
| Wood Innovations (Holdings) Ltd | Financial services | 2017 |
| Wood Innovations Limited | Wholesale & retail | 1996 |
| Wood Worx Carpentry Ltd. | Construction | 2015 |
| Woodgate Apartments (NO2) Development Management Company Limited | Real estate | 2013 |
| Woodgate NO1 Apartments Management Co Ltd | Real estate | 2011 |
| Woodlands Trading Ltd | Hospitality | 2023 |
| Woods Academy Limited | Education | 2025 |
| Woods Fuels Ltd | Wholesale & retail | 2019 |
| Woods Holdings IRL Limited | Financial services | 2022 |
| Woodside Residential Investments Ltd | Construction | 2021 |
| Woodvale Estates Management Limited | Construction | 2017 |
| Woodvale Storage Limited | Real estate | 2021 |
| Worldwide Corporate Advisors LLP (N.I.) Ltd | Extraterritorial | 2022 |
| Wowsie Safety Solutions Ltd | Construction | 2022 |
| Wrenchsoft Ltd | Information & communication | 2025 |
| WSI Group Ltd | Financial services | 2021 |
| Wyatt Mcateer Contracts Ltd | Construction | 2003 |
| Wynncroft Properties Limited | Real estate | 2002 |
| X Essentials Ltd | Wholesale & retail | 2026 |
| XCAV8 Construction (NI) Ltd | Construction | 2017 |
| XMG Construction Limited | Construction | 2021 |
| XMG Furniture Ltd | Manufacturing | 2021 |
| Xupinbo Limited | Wholesale & retail | 2024 |
| Yamazakis Ltd | Transport & logistics | 2024 |
| Yellow Rock Sanctuary CIC | Hospitality | 2023 |
| Yenwod Ltd | Hospitality | 2014 |
| Yes-Eu Limited | Wholesale & retail | 2023 |
| YEW Coffee Ltd | Hospitality | 2025 |
| YEW Tree Dental Practice Limited | Health & social care | 2013 |
| YEW Tree Developments & Investments Ltd | Real estate | 2005 |
| YEW Tree Estates Ltd | Real estate | 2004 |
| YEW Tree Safety Limited | Health & social care | 2024 |
| Yilmaz Ahmet Ltd | Wholesale & retail | 2024 |
| YM Nutrition Ltd | Administrative & support | 2023 |
| Yohan Newry Limited | Real estate | 2015 |