| NGC Hospitality Ltd | Real estate | 2020 |
| NI Autolease Limited | Wholesale & retail | 2022 |
| NI Cars Ltd | Wholesale & retail | 2021 |
| NI Legal Search Company Limited | Professional & scientific | 2020 |
| NI Leisure Services Ltd | Wholesale & retail | 2024 |
| NI Properties Limited | Real estate | 2001 |
| NIC Ruaidhrí Ltd | Agriculture & fishing | 2020 |
| Nifoods Ltd | Hospitality | 2012 |
| Nirox Limited | Wholesale & retail | 2023 |
| Nixon Construction Management Limited | Construction | 2019 |
| NKB Electrical Services Ltd | Construction | 2017 |
| NL Competitions NI Ltd | Arts & recreation | 2025 |
| NMC Ortho Ltd | Health & social care | 2026 |
| NMD Studio Ltd | Professional & scientific | 2026 |
| NMK Construction Services Ltd | Construction | 2021 |
| NO More Ladders Limited | Administrative & support | 2019 |
| Noage Energy Ltd | Energy | 2004 |
| Noble Freight NI Limited | Transport & logistics | 2018 |
| North East Printing Ltd | Wholesale & retail | 2024 |
| North South Logistics Ltd | Transport & logistics | 2021 |
| North West Carriers Ltd | Transport & logistics | 2015 |
| North West Consultancy Ltd | Professional & scientific | 2021 |
| North West Data Ltd | Information & communication | 2023 |
| North West Safety Solutions Ltd | Construction | 2025 |
| North West Trading N. Ireland Limited | Wholesale & retail | 2010 |
| Northbank Risk Management Limited | Financial services | 2016 |
| Northern Refrigeration Services (Belleek) Ltd | Energy | 2011 |
| Northern Smokehouse Ltd | Manufacturing | 2015 |
| NPM Machinery Ltd | Administrative & support | 2021 |
| NT Medica Ltd | Health & social care | 2026 |
| Nude Lashes Ltd | Wholesale & retail | 2023 |
| Nwest Transport Limited | Wholesale & retail | 2016 |
| NWF Feeds Limited | Wholesale & retail | 2017 |
| O'Doherty's Ltd | Hospitality | 2022 |
| O'Malley Farms Ltd | Agriculture & fishing | 2020 |
| O'Reilly Developments Limited | Construction | 2004 |
| Oak and Rose Ltd | Real estate | 2025 |
| Oakdrum Ltd | Construction | 2023 |
| Oakwood Childcare Limited | Health & social care | 2014 |
| Occidentis Ltd | Wholesale & retail | 2018 |
| Ocean Mile Investments Limited | Real estate | 2022 |
| ODD Shoes Limited | Health & social care | 2013 |
| Odessa CL Limited | Other services | 2017 |
| OGD Aerospace Limited | Professional & scientific | 2015 |
| OHS Management Company Ltd | Households | 2012 |
| OJK Commercial Limited | Professional & scientific | 2025 |
| Olcote Properties Ltd | Real estate | 2022 |
| Old Henry Street Management Company Limited | Households | 2014 |
| Oldbrier Limited | Real estate | 2003 |
| OLS Draincare Ltd | Water & waste | 2024 |
| ON Record Productions Limited | Information & communication | 2026 |
| Optical Prime Ltd | Wholesale & retail | 2023 |
| Opus Limited | Professional & scientific | 2015 |
| Orchid Nails Limited | Other services | 2022 |
| P O Maguire and Associates Ltd | Health & social care | 2019 |
| P&K Murphy Contracts Limited | Construction | 2018 |
| P&M Contracts Ltd | Construction | 2023 |
| P&S Boyle Farms Ltd | Agriculture & fishing | 2021 |
| P. J. Flanagan & Co Ltd | Professional & scientific | 2012 |
| P.Axente Framework Ltd | Construction | 2026 |
| P.D.H. (Midway) Limited | Wholesale & retail | 2010 |
| P.D.H. (Newtownbutler) Limited | Wholesale & retail | 2021 |
| P.D.H. Stores Limited | Wholesale & retail | 2010 |
| P.G. Clarke & SON Ltd | Administrative & support | 2013 |
| P.J. Treacy & Sons Limited | Construction | 1997 |
| PA Love Ltd | Hospitality | 2019 |
| Paget Properties Ltd | Real estate | 1995 |
| Palmbush Spar Ltd | Wholesale & retail | 2025 |
| Pamar Properties Ltd | Real estate | 2024 |
| PAR4OUR Limited | Professional & scientific | 2016 |
| PAR5IVE Ltd | Professional & scientific | 2021 |
| Parke Developments Ltd | Real estate | 2006 |
| Parkinson Properties (NI) Limited | Professional & scientific | 2005 |
| Parkinson's Support | Health & social care | 2012 |
| Paswe Transport Ltd | Transport & logistics | 2025 |
| Pathfinder Heritage Trust Limited | Arts & recreation | 2015 |
| Pathways to Emotional Freedom CIC | Professional & scientific | 2025 |
| Patton Rainey Stenson Limited | Professional & scientific | 2022 |
| Paul & Sabrina Gamble Ltd | Real estate | 2018 |
| Paul Hughes Pharmacy Ltd | Wholesale & retail | 2021 |
| Paul Mcgowan Financial Services Ltd | Financial services | 2013 |
| PAW by Four Ltd | Wholesale & retail | 2026 |
| PC Farms Limited | Agriculture & fishing | 2014 |
| Peanut Head Productions Ltd | Arts & recreation | 2026 |
| Pearl Mahon Limited | Hospitality | 2011 |
| Peco Transport Limited | Transport & logistics | 2025 |
| Pelde Ltd | Hospitality | 2020 |
| Peloros Limited | Manufacturing | 2015 |
| People Recruit Limited | Professional & scientific | 2021 |
| People Services Limited | Administrative & support | 2000 |
| Pet Parcels Ltd | Professional & scientific | 2017 |
| Peter Brown Consulting Ltd | Information & communication | 2013 |
| Peter Mulrone Financial Planning Ltd | Financial services | 2024 |
| Petrol Smith Automotive Ltd | Wholesale & retail | 2026 |
| PFC Contracts NI Limited | Construction | 2023 |
| PGD Construction Limited | Construction | 2017 |
| PGD Consultancy Limited | Professional & scientific | 2025 |
| PGD Property Investments Ltd | Real estate | 2021 |
| PGG Commercials Ltd | Wholesale & retail | 2026 |
| Philip Turner Hairdressing Ltd | Other services | 2011 |