| Walltech Group Ltd | Construction | 2025 |
| Walltech Plastering & Drylining Ltd | Construction | 2017 |
| WAN Properties Limited | Real estate | 2010 |
| Washington House Unlimited | Financial services | 2019 |
| WC Transport Services Ltd | Wholesale & retail | 2011 |
| WE Sway Limited | Transport & logistics | 2005 |
| Web Design (N.I.) Ltd | Information & communication | 2023 |
| Whelan Transport Ltd | Transport & logistics | 2021 |
| Whisper Properties Limited | Professional & scientific | 1999 |
| Whitewater Holdings Limited | Real estate | 2021 |
| Whitsitt Development Company Limited | Construction | 1975 |
| WHR Holdings Armagh Ltd | Financial services | 2025 |
| Wild Hare Coffee Roasters Ltd | Hospitality | 2019 |
| Willdekko Ltd | Transport & logistics | 2006 |
| Willow Wisp Ltd | Arts & recreation | 2020 |
| Willowbank & Farm Properties Ltd | Construction | 2023 |
| Wilson Maintenance Ltd | Administrative & support | 2021 |
| Wine Label Ltd | Extraterritorial | 2006 |
| Wishart Transport Ltd | Transport & logistics | 2016 |
| WJM Fisheries Ltd | Agriculture & fishing | 2024 |
| Wmpb | Manufacturing | 2016 |
| WMT Solutions Ltd | Administrative & support | 2008 |
| Woad Raming Ltd | Wholesale & retail | 2025 |
| Woods Supermarkets (Tandragee) Limited | Wholesale & retail | 2002 |
| Woods Supermarkets Limited | Wholesale & retail | 2001 |
| Woolsey Redman Limited | Real estate | 1997 |
| Wrench Monkey Ltd | Wholesale & retail | 2019 |
| WRM Farm Produce Limited | Transport & logistics | 2016 |
| WS Livingstone & Sons Ltd | Agriculture & fishing | 2020 |
| WTW Developments Limited | Administrative & support | 2017 |
| Wylie Ruddell Ltd | Professional & scientific | 2012 |
| XCJ Consultancy Ltd | Professional & scientific | 2018 |
| Xenos Holdco Limited | Professional & scientific | 2021 |
| Xport Transport Limited | Transport & logistics | 2017 |
| Yan-M Ltd | Construction | 2025 |
| Yarno Holland Contracts Limited | Manufacturing | 2003 |
| Yellow Door at Hillsborough Castle Ltd | Hospitality | 2018 |
| Yelroc Property Group Ltd | Real estate | 2025 |
| Yummy House 2025 Ltd | Hospitality | 2025 |
| Zammo Solutions Ltd | Construction | 2020 |
| Zavmobile Ltd | Wholesale & retail | 2026 |
| Zwecker Engineering Limited | Construction | 2022 |
| Zwecker Holdings Limited | Financial services | 2020 |