| W/Wolf Fitness NI Ltd | Arts & recreation | 2022 |
| Waabros Ltd | Real estate | 2025 |
| Waka Express Moira Ltd | Hospitality | 2025 |
| Waka Lurgan Ltd | Hospitality | 2024 |
| Waring Homes Ltd | Real estate | 2020 |
| Waringfield Homes Ltd | Real estate | 2025 |
| Waringstown Limited | Construction | 2021 |
| Waringstown Properties Limited | Extraterritorial | 2012 |
| Warmth Ltd | Administrative & support | 2004 |
| Warnock Orthopaedics Ltd | Health & social care | 2012 |
| Warywear Ltd | Wholesale & retail | 2023 |
| WAS (N.I.) Properties Limited | Real estate | 2013 |
| Wasabi Crop Limited | Agriculture & fishing | 2016 |
| Wasme Presence Ltd | Wholesale & retail | 2025 |
| Water on the Left Ltd | Wholesale & retail | 2022 |
| Waterside Moira Ltd | Hospitality | 2022 |
| Watson Contracts Ltd | Construction | 2014 |
| Waugh Property and DEV Co Limited | Real estate | 1963 |
| Wcrt Limited | Arts & recreation | 2020 |
| Wdha Properties Limited | Real estate | 2025 |
| Wearelittlebuds Limited | Wholesale & retail | 2020 |
| Weavers Gate Management Company Limited | Households | 2023 |
| Weavers Wood Management Company Limited | Households | 2005 |
| Webcraftni Ltd | Information & communication | 2021 |
| Webtech Zone Limited | Professional & scientific | 2025 |
| WEE Fins Limited | Education | 2017 |
| WEE Jamaica Ltd | Health & social care | 2023 |
| WEE Maloneys Limited | Hospitality | 2023 |
| WEE Power Ltd | Health & social care | 2020 |
| WEE Smackers Ltd | Hospitality | 2023 |
| Weir & Weir Property Limited | Real estate | 2019 |
| Weir + Weir Architects + Designers Ltd | Construction | 2015 |
| Weld & Go Ltd | Manufacturing | 2018 |
| Welfare and Translation Services Ltd | Public administration | 2024 |
| Wellington Park Investments Ltd | Real estate | 2020 |
| Wenjoyni Ltd | Wholesale & retail | 2025 |
| Wesemann Arnd Ltd | Wholesale & retail | 2024 |
| West END Bakery Portadown Limited | Manufacturing | 2017 |
| Westdown Plant Ltd | Mining & quarrying | 2004 |
| Westland Road 1966 Limited | Extraterritorial | 2014 |
| Westport Equipment (UK) Limited | Administrative & support | 2022 |
| WFN Gym Limited | Arts & recreation | 2023 |
| White Mechanical Design and Systems Ltd | Manufacturing | 2026 |
| White Onyx Recruitment Ltd | Administrative & support | 2026 |
| White Skye Limited | Hospitality | 2023 |
| Whites Speedicook Limited | Manufacturing | 1983 |
| Whiteside Contracts Limited | Construction | 2013 |
| WHR Wealth Management Ltd | Financial services | 2014 |
| Wicked Weeds Ltd | Administrative & support | 2025 |
| Wiffen Publications Limited | Information & communication | 2016 |
| Wild Hawk Ltd | Professional & scientific | 2020 |
| Wild Shore (N.I.) Ltd | Manufacturing | 2021 |
| Wilde Floral Studio Limited | Wholesale & retail | 2023 |
| Wilderness Garden Centre Limited | Wholesale & retail | 2016 |
| Wilkinson's Butchers and Deli Ltd | Wholesale & retail | 2015 |
| Will Scott Developments Limited | Construction | 2003 |
| William R Hamilton Limited | Wholesale & retail | 1973 |
| Willingmur Properties Limited | Real estate | 2024 |
| Willis Property Services Ltd | Construction | 2025 |
| Willow Veterinary Group Limited | Professional & scientific | 2016 |
| Willows Yardworks Ltd | Arts & recreation | 2025 |
| Wilmar LLP | | 2022 |
| Wilson Body Repairs & Plates Ltd | Wholesale & retail | 2026 |
| Wind Partners Ltd | Energy | 2012 |
| Windsor Property Management Ltd | Real estate | 2023 |
| Windyridge Homes Limited | Professional & scientific | 1986 |
| Windyridge Limited | Transport & logistics | 2015 |
| Wise Move Property Ltd | Real estate | 2019 |
| Withers Orthopaedics Limited | Health & social care | 2019 |
| WM Gallery Limited | Extraterritorial | 1997 |
| Wolf Made Ltd | Manufacturing | 2017 |
| Wolfhill Farm Ltd | Water & waste | 2025 |
| WON Solutions Ltd | Professional & scientific | 2025 |
| Woodhouse Property & Maintenance Ltd | Agriculture & fishing | 2025 |
| Woodside Holdco NI | Financial services | 2018 |
| Woodvale Dromara Management Company Limited | Households | 2008 |
| Woodville Gate Management Ltd | Households | 2011 |
| Woodville Mews Management Company Limited | Households | 2004 |
| Woodville Wood Ltd | Agriculture & fishing | 2026 |
| Woolsey Concrete Limited | Extraterritorial | 1992 |
| Woolsey Freight Limited | Transport & logistics | 2007 |
| Woolsey Group (NI) Limited | Financial services | 2015 |
| Woolsey Park Limited | Real estate | 2019 |
| Work Life People Ltd | Professional & scientific | 2025 |
| WR Electrical Services Limited | Construction | 2016 |
| WRM Consultancy Limited | Education | 2014 |
| Wrmcc Properties Ltd | Real estate | 2026 |
| WSD Wellness Centre Ltd | Real estate | 2023 |
| Wyndnrg Limited | Professional & scientific | 2023 |
| Xsre.Me Ltd | Wholesale & retail | 2013 |
| XZ Eastern River Limited | Hospitality | 2018 |
| Yellow Hive Ltd | Real estate | 2023 |
| Yoga Quarter (Belfast) CIC | Arts & recreation | 2021 |
| Yoga Quarter Limited | Arts & recreation | 2017 |
| YOU 1ST Mortgages Ltd | Financial services | 2020 |
| YOU First Kitchen Components Ltd | Wholesale & retail | 2013 |
| Younique Fitness Ltd | Arts & recreation | 2026 |
| Your Daily Coffee Ltd | Wholesale & retail | 2017 |
| YPS Surveys Ltd | Professional & scientific | 2024 |
| Z & a Holdings Limited | Construction | 2024 |