| Myresto Ltd | Information & communication | 2022 |
| Mysolarpower NI Limited | Construction | 2025 |
| N & C Plant Sales Ltd | Wholesale & retail | 2025 |
| N & PW Mcadam Auto Repairs Ltd | Wholesale & retail | 2013 |
| N - MAC Developments Ltd | Construction | 2011 |
| N S J Properties Limited | Construction | 2012 |
| N T Accountancy Services Ltd | Professional & scientific | 2016 |
| N&S Mcmurray Holdings Ltd | Financial services | 2026 |
| N&S Properties (N.I.) Ltd | Real estate | 2018 |
| N. Rogers Plumbing & Heating Ltd | Construction | 2021 |
| Nacl Ltd | Manufacturing | 2026 |
| Nadur Ltd | Wholesale & retail | 2025 |
| Nafi Aesthetics Ltd | Other services | 2025 |
| Naiscoil C.L. | Education | 2025 |
| NAK Chasewood Ltd | Wholesale & retail | 2024 |
| Nantuckets Lurgan Limited | Hospitality | 2021 |
| Nantuckets Portadown Limited | Hospitality | 2021 |
| Napsco Limited | Extraterritorial | 1973 |
| Natalie’S Delights Ltd | Manufacturing | 2024 |
| Nathan Clarke Contracts Ltd | Professional & scientific | 2024 |
| Natural Equine Salt Therapy Ltd | Other services | 2021 |
| Natural Salt Therapy Limited | Health & social care | 2019 |
| Nature Tots Ltd | Education | 2026 |
| Nautic Assets Ltd | Real estate | 2024 |
| ND Childcare Limited | Health & social care | 2018 |
| Ndeavour Consultants Ltd | Professional & scientific | 2020 |
| NDR Flooring Ltd | Construction | 2024 |
| NEC Property Limited | Real estate | 2020 |
| Neil Casey Ltd | Financial services | 2022 |
| Neil Mcmullan Ltd | Wholesale & retail | 2003 |
| Neil Rooney Scaffolding Ltd | Construction | 2016 |
| Neill Holdings Ltd | Financial services | 2024 |
| Nelson Matthews Precision Engineering Limited | Manufacturing | 2017 |
| Nemesis Automotive Ltd | Wholesale & retail | 2025 |
| Nesbitt Property Rentals Ltd | Real estate | 2023 |
| Nestled Property Management Ltd | Households | 2024 |
| Net-Finity Holdings Ltd | Professional & scientific | 2014 |
| Neville Singular Limited | Information & communication | 2016 |
| New Creation Design and Print Ltd | Professional & scientific | 2010 |
| New GEN Build Ltd | Construction | 2013 |
| New Leaf Kitchens & Bedrooms Ltd | Professional & scientific | 2014 |
| New Yazu Ltd | Hospitality | 2022 |
| New YOU Plan Limited | Wholesale & retail | 2012 |
| New YUM YUM 2026 Ltd | Hospitality | 2026 |
| New YUM YUM Limited | Hospitality | 2024 |
| Newforge Waste Management Systems Ltd | | 1992 |
| Newgen Services Craigavon | Other services | 2020 |
| Newmac Construction Ltd | Construction | 2016 |
| Newport Developments Ltd | Construction | 2014 |
| Nexa Pro Ltd | Arts & recreation | 2023 |
| Nfhl Holdings Limited | Financial services | 2025 |
| Nhcp Ltd | Real estate | 2024 |
| NI Broadcast Solutions Limited | Information & communication | 2012 |
| NI Car Sales Ltd | Wholesale & retail | 2019 |
| NI Connexions Training Ltd | Education | 2024 |
| NI Custom Import Services Ltd | Wholesale & retail | 2024 |
| NI Lasertech Ltd | Manufacturing | 2023 |
| NI Legal Solutions Limited | Administrative & support | 2025 |
| NI Property Investments Ltd | Real estate | 2018 |
| NI Rentals Ltd | Real estate | 2023 |
| NI Running Hub Ltd | Wholesale & retail | 2020 |
| NI Safety Limited | Administrative & support | 2026 |
| NI Suzuki Group Ltd | Education | 2026 |
| Niagro Limited | Wholesale & retail | 2006 |
| Niamh Designs Ltd | Manufacturing | 2024 |
| Niche Financial Limited | Financial services | 2009 |
| Nicholson Green Management Company Limited | Households | 2015 |
| Nicholson Ventures Limited | Information & communication | 2012 |
| Nicmor N.I. Limited | Other services | 2025 |
| Nifed Ltd | Information & communication | 2018 |
| Nightingale Analytics Ltd | Information & communication | 2017 |
| Ninajack Limited | Wholesale & retail | 2024 |
| Nitoday Group Ltd | Information & communication | 2020 |
| Nivs (Craigavon) Limited | Wholesale & retail | 2025 |
| NJC NI Holdings Ltd | Real estate | 2025 |
| Njrrfg Ltd | Professional & scientific | 2024 |
| NL Properties Limited | Real estate | 2000 |
| NMC Actuarial Limited | Financial services | 2013 |
| Nmcs Solutions Ltd | Professional & scientific | 2021 |
| NMG Electrical NI Limited | Construction | 2024 |
| NMG Enterprises Portadown Ltd | Wholesale & retail | 2026 |
| NO 19 Properties Ltd | Real estate | 2025 |
| Nobound Trading Ltd | Manufacturing | 2024 |
| Noel Burns Hairdressing Limited | Other services | 2014 |
| Noel Miskimmons Limited | Construction | 2003 |
| Nookify Limited | Transport & logistics | 2023 |
| Nordens Online Ltd | Wholesale & retail | 2023 |
| Nordic Contracts Ltd | Extraterritorial | 2014 |
| Nornironvapes Ltd | Wholesale & retail | 2019 |
| North of Ireland Karting Association Ltd | Arts & recreation | 2024 |
| Northern Community Capital Ltd | Professional & scientific | 2026 |
| Northern Distributors Limited | Wholesale & retail | 2002 |
| Northern Ireland HEN Rescue Ltd | Agriculture & fishing | 2012 |
| Northern Ireland Kidney Research Fund Limited | Health & social care | 2004 |
| Northtech Fire & Security Ltd | Administrative & support | 2017 |
| Norton Cross Limited | Real estate | 2004 |
| NOT One Iota Ltd | Construction | 2013 |
| NOT2GRAND Limited | Wholesale & retail | 2025 |
| Novablack Limited | Financial services | 2025 |
| Novoa Ltd | Wholesale & retail | 2026 |