| Ibamble AS | Professional & scientific | 2007 |
| Idelink AS | Professional & scientific | 2026 |
| Iform Holding AS | Arts & recreation | 2022 |
| Iform Treningssenter AS | Arts & recreation | 2012 |
| Ilf Consulting Engineers Norway AS | Professional & scientific | 2013 |
| Img Customs AS | Other services | 2026 |
| Img Holding AS | | 2026 |
| Ineos Bamble AS | Manufacturing | 1993 |
| Ineos E&P (Norge) Petroleum DK AS | Mining & quarrying | 1998 |
| Ineos E&P Norge AS | Mining & quarrying | 1971 |
| Ineos Europe AG Nuf | Wholesale & retail | 2011 |
| Ineos Holdings Norge AS | Wholesale & retail | 2007 |
| Ineos Rafnes AS | Manufacturing | 2000 |
| Ineos Sales Norge AS | Wholesale & retail | 2007 |
| Infragrip AS | Information & communication | 2026 |
| Ingebjørg Hansen AS | Real estate | 2012 |
| Inova AS | Wholesale & retail | 1976 |
| Inovyn Europe Limited Norwegian Branch Nuf | Administrative & support | 2017 |
| Inovyn Norge AS | Manufacturing | 2000 |
| Intersport Brotorvet AS | Wholesale & retail | 2021 |
| Investitio AS | Construction | 2019 |
| Involve Invest AS | | 2022 |
| Is Norpolefin Ans | Manufacturing | 1974 |
| Isdammen 22 AS | Real estate | 2022 |
| Isdammen Holding AS | | 2025 |
| Isdammen Marina AS | Real estate | 2008 |
| Isnesheia Va-Drift SA | Water & waste | 2015 |
| IT Advice AS | Professional & scientific | 2008 |
| Jamru Holding AS | Wholesale & retail | 2023 |
| Jan Kjell Rugtvedt Holding AS | Real estate | 2005 |
| JB Bygg Og Rådgivning AS | Professional & scientific | 2020 |
| JDS Holding AS | Real estate | 2016 |
| JK Hus AS | Construction | 2012 |
| JM Byggservice AS | Construction | 2025 |
| JM Byggservice Holding AS | | 2025 |
| Jmeb Eiendom AS | Real estate | 2023 |
| Jmgs Invest AS | | 2022 |
| Joblo Holding AS | Real estate | 2019 |
| Johansen Prosjektstyring AS | Professional & scientific | 2025 |
| Johnsen Elektro AS | Wholesale & retail | 1985 |
| Jome Invest AS | Construction | 2016 |
| Jordon AS | Professional & scientific | 2017 |
| Jordon Consulting AS | Professional & scientific | 2022 |
| JTM - Bygg AS | Construction | 2022 |
| Kaasa Vekst AS | | 2019 |
| Kafe La Bellas AS | Hospitality | 2018 |
| Kastheia Vann Og Avløpslag SA | Water & waste | 2017 |
| Kawaii Sushi AS | Hospitality | 2015 |
| KC Drift AS | Construction | 2019 |
| KDF Holding AS | | 2022 |
| Kimas Eiendom AS | Real estate | 2003 |
| Kimerud Holding AS | Financial services | 2009 |
| Kimerud Service AS | Manufacturing | 1998 |
| Kiøsterud Begravelsesbyrå AS | Other services | 2021 |
| Kjeldal Elektro AS | Construction | 2005 |
| Kjesan Consult AS | Professional & scientific | 2014 |
| Kjl-Consulting AS | Construction | 2022 |
| Kjøya Hyttegrend AS | Real estate | 2005 |
| Kjøya Hytteutvikling AS | Real estate | 2005 |
| KK Marine AS | Manufacturing | 2006 |
| KL Elektro AS | Construction | 2019 |
| Kleppseter Anlegg AS | Construction | 2018 |
| KLL Invest AS | Construction | 2018 |
| Komplett Hjemmefiksing AS | Administrative & support | 2026 |
| Kongholm Boligutleie AS | Real estate | 2018 |
| Kose Holding AS | Wholesale & retail | 2021 |
| Krabberødveien 8 AS | Real estate | 1965 |
| Kristensen Invest AS | Real estate | 2016 |
| KRT AS | Real estate | 2021 |
| Krusty Holding AS | Construction | 2016 |
| Kvikk Utleie AS | Administrative & support | 2012 |
| Kystklinikken AS | Health & social care | 2019 |
| La Vela AS | Hospitality | 2023 |
| Lac Holding AS | Manufacturing | 1997 |
| Lande Boring AS | Construction | 2021 |
| Lande Brønnboring AS | Construction | 2011 |
| Langesund Rør AS | Construction | 1983 |
| Langmyhr Consulting AS | Professional & scientific | 1989 |
| Lauritsen Maling & Gulvsliping AS | Construction | 2024 |
| Lauritsen Maling Og Gulvsliping Ans | Construction | 2019 |
| Leoma AS | | 2022 |
| Leoma Prosjekt AS | Professional & scientific | 2023 |
| Liengen Kittilsen Skog Ans | Agriculture & fishing | 2005 |
| Liff Holding AS | | 2024 |
| Limbus Holding AS | Professional & scientific | 2012 |
| Litana Ir Ko Nuf | Construction | 2013 |
| Lom Holding AS | | 2020 |
| Longer Life AS | Health & social care | 2021 |
| LRK Drift Og Service AS | Administrative & support | 2026 |
| Lssr Holding AS | | 2020 |
| LUDVIQX1 Holding AS | | 2020 |
| Lundekroken 25 AS | Real estate | 2007 |
| Lundsett & Walle Dykkerservice AS | Construction | 1980 |
| Lys Ide AS | Professional & scientific | 1990 |
| M&S Gruppen AS | Professional & scientific | 2020 |
| M.S Forvaltning AS | Professional & scientific | 2012 |
| Ma-Invest AS | Information & communication | 2005 |
| Magnus Reiser AS | Transport & logistics | 2001 |
| Majestetix Invest AS | Information & communication | 2020 |
| Majo Invest AS | | 2024 |