| Jemis AS | Financial services | 2011 |
| Jenkins AS | Information & communication | 2019 |
| Jet Holding AS | Financial services | 1998 |
| JM Jenssen Maskin AS | Construction | 2010 |
| Jojema AS | Health & social care | 2024 |
| Jon Haugland Bygg AS | Construction | 2020 |
| Jon Tore Sand AS | Transport & logistics | 2017 |
| Joy Helse AS | Wholesale & retail | 2017 |
| JPH 289 Holding AS | | 2023 |
| JTB AS | | 2025 |
| Justbolig AS | Real estate | 2023 |
| Kaarstad Kapital AS | | 2025 |
| Kapitalens Krokodille AS | Professional & scientific | 2023 |
| Kapta AS | Professional & scientific | 2024 |
| KAPTEIN1 Invest AS | Financial services | 2014 |
| Karwat Bygg Gruppen AS | Construction | 2018 |
| KB Lysovate AS | | 2023 |
| Kenaj AS | Transport & logistics | 2025 |
| KHF Consulting AS | Information & communication | 2024 |
| KHF Invest AS | Information & communication | 2020 |
| Ki-Senteret Oslo Limited Nuf | Education | 2010 |
| Kjero Invest AS | Real estate | 2018 |
| Klerck & Gjerstad Eiendom AS | Real estate | 2022 |
| Klubbgutta Da | Wholesale & retail | 2004 |
| Kochar AS | Hospitality | 2021 |
| Komo House AS | | 2023 |
| Korslund Holding AS | | 2024 |
| Kovo Mimak AS | Information & communication | 2012 |
| KRS Resolute Holdings AS | | 2025 |
| Krystallklart Budskap AS | Education | 2011 |
| Ksce Holding AS | | 2024 |
| Kurder King AS | Arts & recreation | 2005 |
| Kvark Bryggeri Da | Manufacturing | 2015 |
| L. Talmont Domus Bygg AS | Construction | 2020 |
| Langeby Holding AS | | 2021 |
| Lars Vethe Holding AS | | 2023 |
| Leann Holding AS | | 2008 |
| Lei En Lur Lærd AS | Professional & scientific | 2023 |
| Lian Finance AS | | 2024 |
| Lille Haveli Heggedal AS | Hospitality | 2023 |
| Lilygarden AS | Information & communication | 2019 |
| Liv Hjemmesykepleie AS | Health & social care | 2025 |
| Lotterud Holding AS | Real estate | 2022 |
| Lutt AS | | 2022 |
| Lux Kosmetiske Klinikk AS | Other services | 2025 |
| M.O Holding AS | Construction | 2021 |
| Ma Horses AS | Real estate | 2025 |
| Maf Invest AS | | 2025 |
| Mahalo Invest AS | | 2025 |
| Mamu Corporation Ans | Wholesale & retail | 2007 |
| Manorella AS | Wholesale & retail | 2025 |
| Manuellterapeut Og Fysioterapeut Kristin Sjo-Nilsen AS | Health & social care | 2018 |
| Mappers AS | Manufacturing | 2022 |
| Marand AS | Construction | 2023 |
| Marse Beauty AS | Other services | 2024 |
| Martas Cafe AS | Manufacturing | 2025 |
| Martin Rønning AS | Construction | 2003 |
| Mathco Drilling Tools AS | Professional & scientific | 1992 |
| Mathea AS | Wholesale & retail | 2018 |
| Matisa AS | Hospitality | 2022 |
| MBD Holding AS | | 2026 |
| MBL Holding AS | Agriculture & fishing | 2021 |
| Me Media AS | Administrative & support | 2022 |
| Megram AS | Information & communication | 2019 |
| Mehdi Pharma AS | | 2026 |
| Mel Asker 10 AS | Real estate | 2024 |
| Mel Asker 15 AS | Real estate | 2024 |
| Mel Asker 16 AS | Real estate | 2024 |
| Membran Entreprenør AS | Construction | 2019 |
| Memogroup AS | Information & communication | 2016 |
| Mesterbolig Og Byggtjeneste AS | Construction | 2002 |
| MHK Consulting AS | Other services | 2022 |
| Mika Bygg AS | Construction | 2022 |
| Mitt Regnskap AS | Professional & scientific | 2020 |
| Mke Revisjon AS | Professional & scientific | 2022 |
| Mmhomex Norge AS | Real estate | 2015 |
| Mo Byggservice AS | Construction | 2021 |
| Mobuko AS | Professional & scientific | 1935 |
| Moen Graving Og Utleie AS | Construction | 2015 |
| Mudball AS | | 2026 |
| Murtett AS | Wholesale & retail | 2018 |
| Mutandis AS | Professional & scientific | 2019 |
| Myhra AS | Construction | 1988 |
| Mørch-Jensen AS | Health & social care | 2020 |
| Namespace AS | Financial services | 2018 |
| Nature and Health AS | Health & social care | 2026 |
| Nautical Consultants Ans | | 1993 |
| Navnelapper AS | Manufacturing | 2012 |
| Nedre Plankedalen Vann & Avløpslag SA | Water & waste | 1999 |
| Nela AS | Administrative & support | 2026 |
| Nelly's Da | Hospitality | 2007 |
| Nessem Eiendom AS | Real estate | 2026 |
| Nextrawave AS | Information & communication | 2006 |
| Nilsen Trepleie AS | Agriculture & fishing | 2014 |
| Nokimed AS | Health & social care | 2012 |
| Nor Konstruksjon AS | Professional & scientific | 2021 |
| Nordac AS | Wholesale & retail | 2016 |
| Nordic Service Support AS | Real estate | 2025 |
| Nordly AS | Professional & scientific | 2021 |
| Norsk Byggstandard AS | Construction | 2022 |