| Ingvald Ystgaards Veg 13B AS | Real estate | 1985 |
| Ingvald Ystgaardsv. 15 AS | Real estate | 2006 |
| Ingvald Ystgaardsvei 23 AS | Real estate | 2005 |
| Ingvald Ystgaardsvei 3B AS | Real estate | 2013 |
| Ingvaldes AS | | 2022 |
| Ingvar Bones AS | Wholesale & retail | 1941 |
| Ingvill Øvsthus Holding AS | | 2022 |
| Inicon AS | Information & communication | 2013 |
| INIT4U Accounting AS | Professional & scientific | 2022 |
| INIT4U AS | | 2025 |
| INIT4U Consulting AS | Professional & scientific | 2022 |
| Initial Force AS | Professional & scientific | 2006 |
| Initio Invest AS | | 1993 |
| Injeksjonsspesialisten AS | Health & social care | 2014 |
| Inmind AS | Professional & scientific | 2024 |
| Inmitto AS | | 2021 |
| Innherredsveien 103 AS | Real estate | 1999 |
| Innherredsveien 12 - 14 II AS | Real estate | 2014 |
| Innherredsveien 14 Ans | Real estate | 1996 |
| Innherredsveien 14 II AS | Real estate | 2022 |
| Innherredsveien 22 AS | Real estate | 2018 |
| Innherredsveien 24 AS | Real estate | 2016 |
| Innherredsveien 48 AS | Real estate | 2019 |
| Innherredsveien 61 AS | Real estate | 2008 |
| Innherredsveien 73 AS | Real estate | 2003 |
| Innherredsveien 86 D AS | Real estate | 2016 |
| Innherredsveien 9 AS | Real estate | 2009 |
| Innherredsveien Eiendom AS | Real estate | 2017 |
| Innofi AS | Professional & scientific | 2016 |
| Innoteam AS | Professional & scientific | 2016 |
| Innovakapital AS | Water & waste | 2012 |
| Innovation Invest AS | | 2012 |
| Innovation Jba AS | Professional & scientific | 2014 |
| Innovative Development & Marketing AS | Professional & scientific | 2000 |
| Innovative Science Projects AS | Professional & scientific | 1996 |
| Innovel AS | Professional & scientific | 2016 |
| Innovive AS | Professional & scientific | 2024 |
| Innredning AS | Wholesale & retail | 2008 |
| Innsep AS | Professional & scientific | 2011 |
| Innsikten Eiendom Singsaker AS | Real estate | 2004 |
| Ino AS | Professional & scientific | 2017 |
| Inorbit Technologies AS | Information & communication | 2025 |
| Inord Eiendom AS | Real estate | 2015 |
| Inoventure AS | | 2015 |
| Inovo AS | Professional & scientific | 2017 |
| Inphase Solutions AS | Professional & scientific | 2019 |
| Inro Invest AS | Financial services | 2005 |
| Insight Sales AS | Professional & scientific | 2015 |
| Insolventia Holding AS | | 2024 |
| Insperiment AS | Financial services | 2018 |
| Inspira Visjon AS | Arts & recreation | 2013 |
| Inspired Group AS | Wholesale & retail | 2020 |
| Instalsos AS | Construction | 2023 |
| Instat AS | Professional & scientific | 1989 |
| Insted AS | Real estate | 2021 |
| Institute for Neutral Energy - Dizens AS | Health & social care | 1999 |
| Institutt for Manuell Terapi Trondheim AS | Health & social care | 2003 |
| Instrat AS | Administrative & support | 2000 |
| Intakt Bilskade Drift AS | Other services | 2023 |
| Intakt Bilskade Holding AS | Other services | 2022 |
| Intakt Bilskade Trondheim AS | Other services | 2010 |
| Intakt Midt AS | Administrative & support | 2020 |
| Intakt Møre AS | | 2025 |
| Intakt Nord AS | | 2024 |
| Intakt Nordvest AS | Other services | 2024 |
| Intakt Sør AS | Other services | 2024 |
| Intakt Vest AS | Other services | 2020 |
| Intakt Øst AS | Other services | 2021 |
| Intco Power AS | Professional & scientific | 2025 |
| Intecom AS | Administrative & support | 2019 |
| Integrated Optoelectronics AS | Manufacturing | 2003 |
| Integrated Solar AS | Professional & scientific | 2008 |
| Intensjonell Holding AS | Professional & scientific | 2024 |
| Intensjonell Utvikling AS | Information & communication | 2025 |
| Intent AS | Professional & scientific | 2021 |
| Inter AS | Financial services | 2005 |
| Inter Management AS | Real estate | 1989 |
| Inter Regnskap AS | Professional & scientific | 2006 |
| Inter-Holding AS | Real estate | 2014 |
| Interbox-Tak Og Fasadevask | Administrative & support | 2003 |
| Intercon AS | Wholesale & retail | 1981 |
| Interform AS | Manufacturing | 1992 |
| Intergaard AS | Real estate | 2014 |
| Interinvest AS | Real estate | 2007 |
| Interiørfoto AS | Professional & scientific | 2023 |
| Intermed AS | Wholesale & retail | 2024 |
| International Development Norway AS | Professional & scientific | 2010 |
| International Merchandiser AS | Wholesale & retail | 2020 |
| Internkontroll AS | Health & social care | 2024 |
| Interprt AS | Information & communication | 2023 |
| Intersport Leangen AS | Wholesale & retail | 2023 |
| Intersport Lefstad AS | Wholesale & retail | 2023 |
| Intertech AS | Wholesale & retail | 2024 |
| Into Your Soul AS | Education | 2024 |
| Intro Music AS | Professional & scientific | 2008 |
| Inv Da | | 2023 |
| Inveco AS | Professional & scientific | 1993 |
| Inventas AS | Professional & scientific | 2007 |
| Invera AS | Information & communication | 2025 |
| Invera Construction AS | Information & communication | 2025 |