| Secper (NI) Limited | Administrative & support | 2013 |
| Select Kitchen Components Ltd | Wholesale & retail | 2014 |
| Sheeny Developments Limited | Real estate | 2005 |
| Shelbourne Motors (Newry) Limited | Wholesale & retail | 2018 |
| SHR Fibre Ltd | Wholesale & retail | 2023 |
| Sitara Morgan Limited | Wholesale & retail | 2011 |
| Sixt Consulting Limited | Information & communication | 2014 |
| SK Car Transport Ltd | Transport & logistics | 2018 |
| Skip Hire Holdings Ltd | Extraterritorial | 2016 |
| Sligo Road Developments Limited | Construction | 2006 |
| Smyth Estates Limited | Real estate | 2021 |
| Smyth Group (N.I) Limited | Financial services | 2021 |
| Smyth Properties (N.I) Limited | Real estate | 2021 |
| Soccer Indoors Ltd | Arts & recreation | 2014 |
| Source DB Ltd | Manufacturing | 2024 |
| Sports Merchandising Ireland Ltd | Wholesale & retail | 2004 |
| Sprayrite Agri Ltd | Agriculture & fishing | 2012 |
| Springco (N.I.) Limited | Manufacturing | 1954 |
| Springfort Precision Engineering Ltd | Professional & scientific | 2018 |
| Springlake Developments Limited | Construction | 2005 |
| ST Marks Holdings Ltd | Other services | 2020 |
| ST. Francis Private Care Home Limited | Health & social care | 2017 |
| Statement of Intent Limited | Wholesale & retail | 2012 |
| Static Industrial Coatings Ltd | Manufacturing | 2015 |
| Stevenson Transport Limited | Transport & logistics | 2020 |
| Stilrum LLP | | 2025 |
| Stonebridge Firewood Limited | Wholesale & retail | 2018 |
| Stonehatch Holdings Ltd | Real estate | 2019 |
| Strawhill Estate Limited | Real estate | 2005 |
| Studio SIXTY3 Architect Ltd | Professional & scientific | 2022 |
| Sunnyside Construction Ltd | Construction | 2023 |
| Sunrise Dairies Limited | Extraterritorial | 2003 |
| Sustain Community Limited | Education | 2020 |
| Svaja Retail Ltd | Wholesale & retail | 2016 |
| T & H Jameson Limited | Extraterritorial | 2014 |
| Talkpoint Portadown Limited | | 1998 |
| Tastisnax Foods Limited | Extraterritorial | 1992 |
| Technidrive Limited | Professional & scientific | 2013 |
| Terrain TEK Ltd | Extraterritorial | 2019 |
| THE Agent (N.I.) Ltd | Real estate | 2020 |
| THE Butcher Shop Portadown Ltd | Wholesale & retail | 2017 |
| THE Chip Wagon Limited | Hospitality | 2025 |
| THE Cookery Nook Bakeries & Coffee Shops Ltd | Manufacturing | 2014 |
| THE Florentine Take Away Ltd | Hospitality | 2012 |
| THE Head O' the Road Ltd | Hospitality | 2017 |
| THE North Armagh Motorcycle and Car Club (OFF Road Section) Limited | Arts & recreation | 2011 |
| THE Property Spot N.I. Ltd | Real estate | 2018 |
| THE Warehouse Gym (N.I.) Limited | Arts & recreation | 2016 |
| Thompson Travel International Ltd | Administrative & support | 2014 |
| THT Logistics Limited | Transport & logistics | 2020 |
| TJ Salt Holdings Ltd | Financial services | 2023 |
| TK Touring Limited | Arts & recreation | 2011 |
| Toasted Wood Limited | Manufacturing | 2019 |
| Toberhewny Developments LLP | | 2021 |
| Tomax Ltd | Real estate | 2021 |
| Total Trees Ltd | Administrative & support | 2023 |
| Treen Property Ltd | Real estate | 2025 |
| Truck & Trailer Maintenance Ltd | Wholesale & retail | 2022 |
| Turkington Holdings Limited | Real estate | 1999 |
| Turkington Properties Limited | Real estate | 2014 |
| Tyremaster and Auto Repairs Ltd | Wholesale & retail | 2025 |
| UK Shearling Company Ltd | Manufacturing | 2023 |
| Ulster Carpet Mills Engineering (R&D) Limited | Financial services | 1996 |
| Unch Ltd | Hospitality | 2015 |
| United Group Export and Import Limited | Wholesale & retail | 2020 |
| United Quad Racing Limited | Arts & recreation | 2026 |
| Unity 21 Ltd | Wholesale & retail | 2023 |
| Universal Meat Company | Wholesale & retail | 1985 |
| UQ Trading Limited | Real estate | 2022 |
| USA Ireland Youth Sports CIC | Education | 2026 |
| V P Jebb Ltd | Extraterritorial | 2012 |
| Vara Trading Limited | | 2003 |
| Vehicle Screens Limited | Administrative & support | 2005 |
| Viking Partners T/A O'Hara's More Than Coffee Limited | Hospitality | 2017 |
| VW Aesthetics Ltd | Other services | 2025 |
| W.D. Irwin & Sons (Portadown) Limited | Manufacturing | 2013 |
| Walk on Therapy Limited | Health & social care | 2023 |
| Walker Mcdonald LLP | | 2020 |
| Wallace Packaging Holdings Limited | Financial services | 2021 |
| Walldith Properties 1 Limited | Real estate | 2023 |
| Walldith Properties 2 Limited | Real estate | 2023 |
| Walldith Properties 3 Limited | Real estate | 2023 |
| Walldith Properties Holdings 1 Limited | Financial services | 2023 |
| Walldith Properties Holdings 2 Limited | Financial services | 2023 |
| Walldith Properties Holdings 3 Limited | Financial services | 2023 |
| Walldith Properties Holdings Limited | Financial services | 2023 |
| Watson Autos Limited | Wholesale & retail | 2026 |
| Well Balanced Minds Ltd | Public administration | 2025 |
| Wg.Sap Ltd | Construction | 2025 |
| White Co. Laundry Ltd | Administrative & support | 2024 |
| White Light N.I Limited | Health & social care | 2024 |
| Wilson Traders Ltd | Hospitality | 2025 |
| Wilson's Foodstores Ltd | Wholesale & retail | 2020 |
| Wilsons Foodstore (Carn) Ltd | Wholesale & retail | 2022 |
| Windyridge Investments Limited | | 2006 |
| WIT Distribution Ltd | Wholesale & retail | 2023 |
| Wright Fit N.I Limited | Arts & recreation | 2022 |