| Miks AS | Professional & scientific | 2013 |
| Mima Skeppa Och Industriservice AB | Manufacturing | 2003 |
| Mimiri AS | Information & communication | 2026 |
| Mitt Bad AS | Construction | 2016 |
| Mitt Tak AS | Construction | 2024 |
| MJT Holding AS | Financial services | 2005 |
| MKS Eiendom AS | Real estate | 2025 |
| Mmollere Holding AS | Real estate | 2017 |
| Mobildata Sarpsborg AS | Wholesale & retail | 2001 |
| Mobile Sarpsborg AS | Other services | 1991 |
| Mocycle Norge AS | Wholesale & retail | 2024 |
| Modström AS | Wholesale & retail | 2012 |
| Modulvegger Østfold AS | Wholesale & retail | 2016 |
| Mohammed Ahmed Esam Dental AS | Health & social care | 2025 |
| Mokastet Holding AS | Information & communication | 1994 |
| Morten Bergerud-Karlsen AS | Construction | 2005 |
| Morten Grasto AS | | 2024 |
| Morten Oliversen AS | Construction | 2008 |
| Mossefossen Ans | Energy | 1985 |
| Mossefossen AS | Energy | 2000 |
| Movearound Norway AS | Professional & scientific | 2024 |
| MR. Bowl Sarpsborg AS | Hospitality | 2022 |
| MRF Sarpsborg AS | Hospitality | 2023 |
| Ms-Bygg AS | Construction | 2022 |
| Mulli Club AS | Wholesale & retail | 2026 |
| Multihandel Norge AS | Wholesale & retail | 2023 |
| Murerfirma Dennis Thomassen AS | Construction | 2017 |
| MVP Invest AS | Real estate | 2022 |
| My Motown AS | Professional & scientific | 2012 |
| Mze Eiendom AS | Real estate | 2026 |
| Møller-Eriksen Invest AS | Professional & scientific | 1998 |
| Møllerhagen Nordli Holding AS | | 2024 |
| Mørk Trafikkskole AS | Education | 2008 |
| N Eiendom AS | Real estate | 2019 |
| N.S Auto AS | Wholesale & retail | 2022 |
| N3PRENØREN AS | Construction | 2013 |
| Nacon AS | Financial services | 2017 |
| Nafziger AS | | 2013 |
| Nails by Design AS | Other services | 2025 |
| Nbi Kompetansepartner AS | Education | 2000 |
| Nedre Glomma Ressurssenter Da | Other services | 2010 |
| Nedre Glomma Øyekirurgi AS | Health & social care | 2020 |
| Nedre Glommen Assuranse AS | Financial services | 2005 |
| Nedre Glommen Eiendom AS | Real estate | 2010 |
| Nedre Glommen Holding AS | Education | 1998 |
| Nellys Tune AS | Hospitality | 2024 |
| Netfit AS | Health & social care | 2020 |
| Network Design Engineer AS | Information & communication | 2023 |
| Next Level Gym Og Fitness AS | Arts & recreation | 2022 |
| Noble Tiny Tales AS | Information & communication | 2026 |
| Nobo Holding AS | | 2025 |
| Nobo Invest AS | Wholesale & retail | 2023 |
| Noe for Nett AS | Information & communication | 2016 |
| Nor-Graphic Limited AS | Wholesale & retail | 1971 |
| Nor-Tech Inspection AS | Real estate | 2005 |
| Norborg Eiendom AS | Real estate | 2025 |
| Norborg Holding AS | Real estate | 2025 |
| Norborg Utleie AS | Real estate | 2026 |
| Norborg Utvikling AS | Real estate | 2022 |
| Norcard Event & Marketplace AS | Arts & recreation | 2023 |
| Nordhagen & Co Holding AS | Other services | 2010 |
| Nordhagen & Co Invest AS | Other services | 2010 |
| Nordhavn Bygg AS | Construction | 1998 |
| Nordhavn Bygg Da | Real estate | 1990 |
| Nordhold AS | | 2026 |
| Nordic Aviation Advisory AS | Transport & logistics | 2026 |
| Nordic Special Project AS | Construction | 2022 |
| Nordisk Revisjon AS | Professional & scientific | 2023 |
| Nordisk-Bygg AS | Construction | 2014 |
| Norditech AS | Information & communication | 2026 |
| Nordli Eiendomsutleie AS | Real estate | 2020 |
| Nordli Sport AS | Wholesale & retail | 2020 |
| Nordli Sport Holding AS | Wholesale & retail | 2024 |
| Nordtug Bil & Eiendom AS | Wholesale & retail | 1996 |
| Norix AS | Wholesale & retail | 2026 |
| Norlat Shipping Ltd AS | Transport & logistics | 1986 |
| Normann Kirkerud Holding AS | | 2022 |
| Norpro Entreprenør AS | Real estate | 2024 |
| Norrak Holding AS | | 2025 |
| Norsk Bil- Og Båtimport AS | Wholesale & retail | 1983 |
| Norsk Mineralutvikling AS | Professional & scientific | 2000 |
| Northern Food Norway AS | Wholesale & retail | 2024 |
| Nortic AS | Professional & scientific | 2012 |
| Norway Fried Chicken AS | Hospitality | 2019 |
| Notabene Music Stand AS | Wholesale & retail | 2017 |
| Nova Scooter AS | Administrative & support | 2026 |
| Novicell No AS | Information & communication | 2018 |
| Np-Holding AS | | 2022 |
| Numerika AS | Professional & scientific | 2014 |
| Nutracell AS | Manufacturing | 1987 |
| Nuwa AS | | 2023 |
| Nuwa Holding AS | Construction | 2023 |
| Nye Cafe Moldebadet AS | Hospitality | 2014 |
| Nye Dickens Sarpsborg AS | Hospitality | 2025 |
| Nye Frisørhuset Hår Og Velvære AS | Other services | 2018 |
| Nye Modena AS | Wholesale & retail | 2010 |
| Nye Neptune Pub AS | Hospitality | 2004 |
| Nye Paradis Pizza AS | Hospitality | 2022 |
| Nye Sarpen Dagligvare AS | Wholesale & retail | 2025 |
| Nye Øa Drift AS | Construction | 2026 |