| Jan Sveistrup Holding AS | | 2020 |
| Jansen Invest Og Drift AS | Real estate | 1999 |
| Jegerpakka Da | Wholesale & retail | 2006 |
| Jim Holding AS | Professional & scientific | 2007 |
| Jimborch AS | | 2021 |
| Johan Hansen Glass & Aluminium AS | Construction | 1916 |
| JT Dream Car AS | Wholesale & retail | 2023 |
| Juletregutta AS | Wholesale & retail | 2022 |
| Juliren Studio AS | Other services | 1981 |
| Kaffeskvetten AS | Hospitality | 2020 |
| KB Quality Inspection AS | Professional & scientific | 2025 |
| Keiserens Nye Herre Og Ungdomsklær Da | Wholesale & retail | 2009 |
| Killingmo & Tønsberg AS | Manufacturing | 1987 |
| Kjellingmoveien 1 AS | Real estate | 2020 |
| Kjellingmoveien 4 AS | Real estate | 2023 |
| Kjøkkenstudio Aurskog AS | Wholesale & retail | 2018 |
| Klostransport AS | Transport & logistics | 2026 |
| Knut Haneborg AS | Agriculture & fishing | 2010 |
| Kongelige Gulv AS | Construction | 2021 |
| Kontakt Elektro AS | Construction | 2022 |
| Kristoffer Byggservice AS | Construction | 2024 |
| KTV - AS | Construction | 2022 |
| KVV Utleie AS | Administrative & support | 2023 |
| Kværnhaugen Eiendom AS | | 2014 |
| L-Spar AS | Real estate | 2012 |
| La Mama AS | Education | 2026 |
| Langrute AS | Wholesale & retail | 2021 |
| Leiepakking AS | Real estate | 1992 |
| LHJ AS | Financial services | 2018 |
| Lierfoss Eiendom Ans | Real estate | 2001 |
| Lierfoss Holding AS | | 2021 |
| Lierfoss Invest AS | Real estate | 2009 |
| Lierfoss Transportsentral AS | Transport & logistics | 2022 |
| Lillestrøm Hundesenter AS | Other services | 2022 |
| Lillestrøm Logistikk AS | Transport & logistics | 2018 |
| Lillestrøm Transport Og Logistikk AS | Transport & logistics | 2022 |
| Linjekvartalet Bolig AS | Real estate | 2012 |
| Llas Holding AS | Transport & logistics | 2022 |
| Luca AS | Real estate | 2019 |
| Luftveien 4 AS | Real estate | 2018 |
| Lunde Transport & Service AS | Transport & logistics | 2023 |
| Lysaker AS | Real estate | 2013 |
| M&R Bakke Holding AS | Real estate | 2013 |
| Marion Reith AS | Health & social care | 2015 |
| Mediehuset Blåne AS | Information & communication | 2025 |
| Mel Asker 13 AS | Real estate | 2024 |
| Mel Heia 37 AS | Real estate | 2022 |
| Mellum AS | Manufacturing | 2006 |
| Mester Bygg & Eiendomsutvikling AS | Construction | 2010 |
| Metmas AS | Wholesale & retail | 2024 |
| Michal Srogoncik AS | Wholesale & retail | 2025 |
| Mikael Håndverker AS | Construction | 2017 |
| Milla Lab AS | Professional & scientific | 2024 |
| Mittegetlokale Brumunddal AS | Real estate | 2022 |
| Mittegetlokale Killingmo AS | Real estate | 2022 |
| MLT AS | Professional & scientific | 2019 |
| MM Bruktbil AS | Wholesale & retail | 2023 |
| Moerveien Utvikling AS | Real estate | 2021 |
| Montasje Reoler AS | Construction | 2023 |
| Monteringsgutta AS | Professional & scientific | 2015 |
| Montør AS | Construction | 2024 |
| Moot Eiendom AS | Real estate | 2004 |
| Morten Haneborg AS | Transport & logistics | 2022 |
| Morten Krogstad Holding AS | Education | 2023 |
| Moto Skaperglede AS | Hospitality | 2025 |
| MRB Holding AS | Wholesale & retail | 2012 |
| Mærli Engineering AS | Professional & scientific | 1991 |
| Møbelmiljø Aurskog AS | Wholesale & retail | 1988 |
| Møllestrøket Holding AS | Real estate | 2026 |
| Møllestrøket Prosjekt AS | Real estate | 2026 |
| Møllestrøket Utvikling AS | Real estate | 2020 |
| N-Sport Da | Wholesale & retail | 2004 |
| N. Mangen Gaard AS | Agriculture & fishing | 2023 |
| Nannestad Eiendom Utvikling AS | Real estate | 2010 |
| Natlink AS | Wholesale & retail | 2023 |
| Navitek AS | Information & communication | 2007 |
| Nedre Haug AS | | 2018 |
| Niklas Eriksen AS | Construction | 2021 |
| Nilssen Assuranse AS | Financial services | 2022 |
| Nitteberg Panorama Holding AS | Real estate | 2015 |
| Norbak AS | Manufacturing | 2014 |
| Nordbrand AS | Professional & scientific | 2024 |
| Nordcraft Solutions AS | Construction | 2026 |
| Nordic Layer AS | Wholesale & retail | 2025 |
| Nordisk Maler AS | Construction | 2026 |
| Nordkraft Siedlecka AS | Manufacturing | 2026 |
| Nordli Invest AS | Construction | 2003 |
| Norgania AS | Wholesale & retail | 2021 |
| Norgårdfoto Ans | Professional & scientific | 2010 |
| Norital AS | Wholesale & retail | 2014 |
| Normex Energy Consultants AS | Real estate | 2002 |
| Norsecraft Geo AS | Professional & scientific | 2010 |
| Norsk Nettskole AS | Education | 2017 |
| Norske Antti AS | Wholesale & retail | 2021 |
| Norske Ski AS | Wholesale & retail | 2014 |
| NS Maskin AS | Construction | 2019 |
| Numerus Finans AS | Professional & scientific | 2019 |
| Ole Brumm Barnehage Aurskog AS | Education | 2014 |
| Ozog Service AS | Construction | 2024 |
| Paddy Sportsreiser AS | Administrative & support | 2010 |