| Inlink AS | Administrative & support | 2005 |
| Inm Invest AS | | 2026 |
| Innskuddspensjonstjenester AS | Information & communication | 2014 |
| Innspurten Eiendom AS | | 2025 |
| Innspurten Utvikling AS | | 2023 |
| Insanity Holding AS | | 2026 |
| Inter-Gastro AS | Wholesale & retail | 2005 |
| Interpress Norge AS | Wholesale & retail | 2001 |
| Inwestnor Sp.Z.O.O Nuf | Construction | 2016 |
| Iras AS | Administrative & support | 2025 |
| Irfan Holding AS | | 2024 |
| Isakveien 18/20 AS | Real estate | 2009 |
| Ittar AS | Wholesale & retail | 2026 |
| Ivan Transport AS | Transport & logistics | 2025 |
| J & T Eiendom AS | Real estate | 2026 |
| J&Co Storgata AS | Hospitality | 2025 |
| J&J Investment AS | Real estate | 2008 |
| J&J Kløvertunet E AS | Real estate | 2022 |
| J.A.S Holding AS | | 2025 |
| Jaa 1 Holding AS | | 2021 |
| Jakhelln AS | Construction | 1969 |
| Jakhelln Bioenergi AS | Professional & scientific | 2009 |
| Jakhelln Entreprenør AS | Construction | 1996 |
| Jakhelln Logistikk AS | Transport & logistics | 2001 |
| JAKOBS1 Invest AS | Professional & scientific | 2014 |
| Jamay AS | Hospitality | 2025 |
| Jansen Musikk Ans | Wholesale & retail | 1991 |
| Jarle & Bjørnar Fluefiske AS | Wholesale & retail | 1991 |
| Jass Bygg AS | Construction | 2020 |
| JBN AS | Professional & scientific | 2015 |
| JBN Rentals AS | Administrative & support | 2024 |
| JBN Services AS | Professional & scientific | 2014 |
| JCJ Holding AS | | 2023 |
| Je-Byggeadministrasjon AS | Professional & scientific | 2017 |
| Jeni Invest AS | | 2022 |
| Jensen & Co AS | Wholesale & retail | 1986 |
| JH Spårservice AS | Construction | 2014 |
| JK Livin AS | Health & social care | 2019 |
| Jmtb Holding AS | | 2022 |
| Jo Invest AS | Real estate | 2006 |
| Johnsen Og Gulliksen Ans | Administrative & support | 2003 |
| Join Rådgivning AS | Professional & scientific | 2024 |
| Jonas Liesgate 42 AS | Real estate | 1990 |
| Jop Holding AS | | 2005 |
| Joss AS | Manufacturing | 2006 |
| Jot Invest AS | Financial services | 2005 |
| JPF AS | Professional & scientific | 2019 |
| Jsa Holding AS | Financial services | 2008 |
| JSS Bygg AS | Construction | 2018 |
| Julie Fossum Skjølberg AS | | 2021 |
| Junior Eiendom AS | Real estate | 2021 |
| Junol AS | Information & communication | 2005 |
| Jølsen Eiendom 3 AS | Real estate | 2020 |
| Jølsen Eiendom 5 AS | Real estate | 2024 |
| Jølsen Miljøpark AS | Manufacturing | 2004 |
| Jølsenveien 26 AS | Real estate | 2020 |
| K Business Consulting AS | Professional & scientific | 2021 |
| K Gulden Ans | Construction | 1988 |
| K&R Paulsberg AS | Education | 2025 |
| K. E. Onstad Holding AS | Real estate | 2005 |
| K4 Group AS | Administrative & support | 2016 |
| Kainaat Invest AS | Hospitality | 2017 |
| Kalbakken Senter AS | Real estate | 2002 |
| Kales Airline Services AS | Transport & logistics | 1999 |
| Kanalveien Handel AS | Wholesale & retail | 2026 |
| Kaos Consulting AS | Professional & scientific | 2017 |
| Kari-Jannes Salong AS | Other services | 1986 |
| Karius AS | | 2026 |
| Karl Jensen AS | Manufacturing | 2008 |
| Kasu Eiendom AS | Real estate | 2024 |
| Kasu Holding AS | Professional & scientific | 2023 |
| Kasu Regnskap AS | Professional & scientific | 2024 |
| Katc Invest AS | Real estate | 2022 |
| Kaupang Eiendom AS | Real estate | 2022 |
| Kaupang Sales AS | Professional & scientific | 2023 |
| Kaur Holding AS | Health & social care | 2022 |
| Kavma AS | Professional & scientific | 2026 |
| Kavma Invest | Financial services | 2016 |
| Keibot AS | Real estate | 2013 |
| Keiser Fruktmarked AS | Wholesale & retail | 1998 |
| Kenbra Holdning AS | Real estate | 2024 |
| Kent F Invest AS | | 2026 |
| Kentaur Invest AS | | 2023 |
| Keser Internasjonal Holding AS | Real estate | 2022 |
| KESER1 AS | Wholesale & retail | 2022 |
| Keune Haircosmetics Norway AS | Wholesale & retail | 2024 |
| Kevin Berghagen AS | | 2024 |
| KGB Trading AS | Real estate | 2013 |
| Kidane Taxi Da | Transport & logistics | 2025 |
| Kino's Lillestrøm AS | Hospitality | 2015 |
| Kioskdrift Sørumshagen AS | Wholesale & retail | 2026 |
| Kirkeparken Næringseiendom AS | Real estate | 2019 |
| Kiropraktor Asmyhr AS | Health & social care | 2020 |
| Kishore Invest AS | | 2026 |
| KJ Byggservice AS | Construction | 2016 |
| Kjedehuset AS | Construction | 2023 |
| Kjedehuset Handel AS | Construction | 2025 |
| Kjeksrud Holding AS | | 2019 |
| Kjeller Innovasjon AS | Professional & scientific | 1995 |
| Kjeller Vest 14 AS | Real estate | 2019 |