| Industrie AS | Financial services | 2013 |
| Infrapro AS | Information & communication | 2017 |
| Ing Paal Lefdahl Entreprenørforretning AS | Construction | 1990 |
| Innocreate AS | Real estate | 2011 |
| Inspera Gruppen AS | Information & communication | 1999 |
| Inspirea Home AS | Wholesale & retail | 1975 |
| Instrumentteam AS | Wholesale & retail | 2003 |
| Intermezzo Frisør AS | Other services | 1997 |
| International Speech and Language Services AS | Health & social care | 2015 |
| Inveto AS | Real estate | 1998 |
| Inveto Consult AS | Professional & scientific | 2007 |
| Inveto Prosjekt AS | Real estate | 2008 |
| Inyheter AS | Information & communication | 2022 |
| Ipn Holding AS | Real estate | 2018 |
| Iskov Kapital AS | | 2025 |
| Iso Forum AS | Professional & scientific | 2026 |
| Isox AS | Professional & scientific | 2023 |
| Istind Capital AS | | 2021 |
| Italia Partner AS | Administrative & support | 2020 |
| Iterreng AS | Wholesale & retail | 2014 |
| Iterum AS | Information & communication | 2026 |
| Itrade AS | Professional & scientific | 2004 |
| Its a Lie Venture AS | Information & communication | 2016 |
| J. Lyng Holding AS | Information & communication | 2017 |
| Jacek Borg AS | Professional & scientific | 2017 |
| Jale AS | Professional & scientific | 2025 |
| Jamne AS | Professional & scientific | 1987 |
| Janska Invest AS | Real estate | 2005 |
| Jar Bygg AS | Construction | 2012 |
| Jar Bygg Eiendom 1 AS | Real estate | 2024 |
| Jeje Internett Service Ans | Information & communication | 2001 |
| Jessheim Boligutvikling AS | | 2009 |
| JFN Holding AS | Professional & scientific | 2014 |
| JHL Eiendom AS | Real estate | 2024 |
| Joboco AS | Financial services | 2006 |
| Jodin AS | | 2020 |
| Johabo AS | | 2023 |
| Johanne Rogndal AS | Health & social care | 2017 |
| John Rui A/S | Real estate | 1961 |
| John Solo AS | | 2023 |
| Johnny Karlsen AS | Wholesale & retail | 2000 |
| Jojaju Invest AS | | 2020 |
| Jordmorstua Ans | | 1994 |
| Josom 426 Holding AS | | 2023 |
| Jott AS | | 2021 |
| Jumpking AS | Wholesale & retail | 1998 |
| Juterud Invest AS | Real estate | 2005 |
| Jørgensen Marlow Invest AS | Professional & scientific | 2025 |
| K Kvia Holding AS | | 2018 |
| Kadi Invest AS | Real estate | 2013 |
| Kakamo Invest AS | Financial services | 2011 |
| Kalnæs AS | Real estate | 1962 |
| Kan Frisører Bærum AS | Other services | 2024 |
| Karma Invest Eiendom AS | Real estate | 2016 |
| Kathrines Invest AS | Financial services | 2015 |
| Katos Holding AS | | 2023 |
| Katy Invest AS | Real estate | 2017 |
| Kaventure AS | | 2020 |
| Kda Holding AS | Professional & scientific | 2017 |
| Kenai AS | Professional & scientific | 2019 |
| Kenjak AS | Wholesale & retail | 2021 |
| Kethees AS | Real estate | 2019 |
| Kethees Eiendom AS | Real estate | 2008 |
| KG Prosjekt AS | Professional & scientific | 2018 |
| Kikut Investor AS | Professional & scientific | 2021 |
| Kirin Invest AS | Financial services | 2013 |
| Kirkeveien 92 Eiendom AS | Real estate | 2017 |
| Kise Kommunikasjon AS | Professional & scientific | 2017 |
| Kjellsea Invest AS | | 2019 |
| Kjellvika Vann Og Avløp SA | Water & waste | 2019 |
| Kjeveortoped Trond Anders Kristensen AS | Health & social care | 2022 |
| Kjærringa Med Stakken AS | Manufacturing | 2018 |
| KK Bygg & Service AS | Construction | 2020 |
| Klinvest AS | | 2000 |
| Kma Invest AS | Real estate | 2012 |
| Kmrg Holding AS | | 2021 |
| Knutsam AS | Financial services | 2006 |
| Kodemagisk AS | Information & communication | 2026 |
| Komplemento AS | Financial services | 2004 |
| Konsept Helse AS | Health & social care | 2026 |
| Konsili AS | Professional & scientific | 2022 |
| Kraft Bygg Gruppen AS | Real estate | 2025 |
| Kristian Schiander Holding AS | Financial services | 2017 |
| Krogsveen Eiendom AS | Real estate | 1993 |
| KSF Holding AS | Construction | 2024 |
| Kudos AS | Real estate | 2018 |
| Kwms AS | Financial services | 2013 |
| KZN AS | | 2020 |
| L12 Eiendomsmegling AS | Real estate | 2017 |
| La Ravine AS | Wholesale & retail | 2019 |
| Larimda Holding AS | Wholesale & retail | 2007 |
| Lasse Evensen AS | Professional & scientific | 2013 |
| LD Eiendom AS | Real estate | 2019 |
| LD Entreprenør AS | Construction | 2021 |
| Lde Holding AS | Construction | 2020 |
| Leadit AS | Information & communication | 2026 |
| Leebow Racing AS | Administrative & support | 2013 |
| Lefdal Holding Invest AS | Real estate | 2022 |
| Leko Ans | Wholesale & retail | 1990 |
| Lerk Entreprenør AS | Construction | 2022 |