| Idexa AS | Professional & scientific | 2026 |
| Idexx Laboratories Norge AS | Professional & scientific | 2011 |
| Idiac Bidco AS | | 2025 |
| Idiac Midco AS | | 2025 |
| Idiac Mipco AS | | 2025 |
| Idiac Topco AS | | 2025 |
| Idig AS | Information & communication | 2005 |
| Idl Handel AS | Transport & logistics | 2024 |
| Idl Solution AS | | 2021 |
| Idlandia AS | Health & social care | 2022 |
| Idlewild Semiconductor AS | Information & communication | 2024 |
| Idm AS | | 2024 |
| Idme Holding AS | | 2021 |
| Idntfy Me AS | Wholesale & retail | 2023 |
| Idobara AS | | 2026 |
| Idol Looks AS | Professional & scientific | 2021 |
| Idol the Lord of Hair AS | Other services | 2015 |
| Idon AS | Professional & scientific | 1988 |
| Idrettens Forsikringsselskap AS | Financial services | 2025 |
| Idrettens Helsesenter AS | Health & social care | 2009 |
| Idrettsakademiet AS | Education | 2020 |
| Idrettsveien 1 Utvikling AS | | 2019 |
| Idrettsveien 2 AS | Real estate | 2023 |
| Idro AS | | 2023 |
| Idsø Invest AS | Financial services | 2008 |
| Idun AS | | 2022 |
| Idun Fus Barnehage AS | Education | 2019 |
| Idur AS | Information & communication | 2024 |
| Idur Cape Selection AS | Wholesale & retail | 2026 |
| Idyia AS | | 2019 |
| Idås Holding AS | | 2021 |
| Idé Hob AS | Wholesale & retail | 2012 |
| Idée Fixe Film AS | Information & communication | 2012 |
| Idéfix Invest AS | Real estate | 2006 |
| Idékapital Growth Horizon AS | Financial services | 2022 |
| Idékapital Investment Management AS | Financial services | 2022 |
| Ie Bygg AS | Construction | 2021 |
| Ie Holding AS | | 2024 |
| Ie North Sea AS | Mining & quarrying | 2026 |
| Ieb AS | | 2020 |
| Iec Telecom Norway AS | Wholesale & retail | 2005 |
| Ieg Investment Banking AS | Professional & scientific | 2020 |
| Ieh Invest AS | | 2023 |
| Iem Invest AS | Real estate | 2015 |
| Iett AS | Wholesale & retail | 2019 |
| Ieu Møbel Invest AS | Real estate | 2006 |
| Ieva AS | Health & social care | 2025 |
| Iexpert AS | Other services | 2021 |
| If Consulting AS | | 2023 |
| If Else AS | Information & communication | 2015 |
| If Finans Nuf | | 2022 |
| If IT Services Nuf | Financial services | 2001 |
| If Livsforsikring Nuf | Financial services | 2005 |
| If Services Nuf | Administrative & support | 2017 |
| If Skadeforsikring Nuf | Financial services | 1999 |
| Ifa Olorun Da | Wholesale & retail | 2024 |
| Ifg Holding AS | Real estate | 1966 |
| Ifkgøteborg AS | | 2024 |
| Ifm Electronic AS | Wholesale & retail | 2021 |
| Ifo Forvaltning Da | | 2026 |
| Ifpi Norge AS | Other services | 1990 |
| Ifra Ans | Education | 2004 |
| Ifront AS | Information & communication | 2000 |
| Ifront Karriere AS | Education | 1996 |
| Ifront Kompetanse AS | Education | 2020 |
| Iftikhar Capital AS | Real estate | 2026 |
| Ifw AS | Construction | 2010 |
| Ifø Electric AS | Wholesale & retail | 2002 |
| Ig 235 Holding AS | | 2023 |
| IG57 IT AS | Information & communication | 2020 |
| Igb AS | | 2021 |
| Ige Invest AS | Real estate | 2012 |
| Igeo AS | Professional & scientific | 2016 |
| Iggy AS | Professional & scientific | 2023 |
| Iggy Holding AS | | 2020 |
| Igi Nordic AS | Financial services | 2009 |
| Igital AS | Information & communication | 2024 |
| Igk Regnskap AS | Professional & scientific | 2006 |
| Igland Holding AS | | 2021 |
| Iglo Invest AS | | 2015 |
| Igloo Eiendom Ans | Real estate | 1993 |
| Igloocar Norge AS | Wholesale & retail | 2015 |
| Igm AS | Education | 2013 |
| Ign Invest AS | Professional & scientific | 2018 |
| Ign VVS AS | Construction | 2014 |
| Ignease Norway AS | Construction | 2026 |
| Ignexa AS | | 2025 |
| Ignis AS | | 2025 |
| Igniscon AS | Financial services | 2013 |
| Ignist AS | Professional & scientific | 2021 |
| Ignite Partners AS | | 2025 |
| Ignite Procurement AS | Information & communication | 2017 |
| Igniva AS | Professional & scientific | 2017 |
| Ignora(S)Mus Corporation AS | | 2021 |
| Ignorantus AS | Information & communication | 2020 |
| Igo AS | Professional & scientific | 2000 |
| Igp AS | | 2026 |
| Igree AS | Information & communication | 2025 |
| Igroc AS | Real estate | 1998 |
| Igroc Consulting AS | Professional & scientific | 2020 |