| Interferens AS | | 2021 |
| Interflex Medizintechnik GmbH | Construction | 2017 |
| Interhost AS | Information & communication | 2010 |
| Interimleder AS | Professional & scientific | 2001 |
| Interiør Design Academy AS | Professional & scientific | 2025 |
| Interiør Ekspert AS | Construction | 2020 |
| Interiør Invest AS | Wholesale & retail | 2005 |
| Interiør-Galleriet AS | Wholesale & retail | 1987 |
| Interiøragenturer J. Sveen AS | Wholesale & retail | 1982 |
| Interiørarkitekt Hilde Aasbø AS | Professional & scientific | 2018 |
| Interiørdesign AS | Wholesale & retail | 1990 |
| Interiørdesigner Tove Meldgaard AS | Professional & scientific | 2012 |
| Interiørdetalj AS | Wholesale & retail | 1989 |
| Interiørfix AS | Other services | 2022 |
| Interiørplan AS | Professional & scientific | 2021 |
| Interiørrådet AS | Professional & scientific | 2025 |
| Interiørsiden Ans | Professional & scientific | 1999 |
| Interiørtema AS | Wholesale & retail | 1986 |
| Interjob AS | | 2007 |
| Interkreditt Kapital AS | Financial services | 2018 |
| Interkulturelt Samvirke Ik SA | Administrative & support | 2024 |
| Interlab Storm Ans | | 1986 |
| Interlope AS | Professional & scientific | 2012 |
| Interlope Consulting AS | Professional & scientific | 2013 |
| Intermec Technologies AB | Wholesale & retail | 1996 |
| Intermec Technologies European Partnership CV | Wholesale & retail | 2000 |
| Intermediate AS | Professional & scientific | 2021 |
| Internasjonal Kulturbarnehage AS | Education | 2021 |
| Internasjonal Kulturbarnehage Åkeberg AS | Education | 2022 |
| Internasjonal Tours AS | Administrative & support | 2006 |
| International Architectural Solutions Holding Limited | | 2022 |
| International Association of Physics Students | Other services | 2005 |
| International Brands AS | Wholesale & retail | 2021 |
| International Bullies AS | Wholesale & retail | 2015 |
| International Business Machines Corporation Magyarorszagi KFT | Information & communication | 2009 |
| International Business Machines of Belgium | Information & communication | 2009 |
| International Competence Centre Tanzania (Icct AS) | Education | 2005 |
| International Corporate Art AS | Administrative & support | 1989 |
| International Døds Federation AS | Professional & scientific | 2014 |
| International Energy Consortium AS | Professional & scientific | 2013 |
| International Ferry Line Inc Norway | Transport & logistics | 2006 |
| International Holiday Services Da | Real estate | 1993 |
| International Library of Fashion Research AS | Arts & recreation | 2024 |
| International Management Education | Professional & scientific | 2008 |
| International Management Invest AS | Real estate | 2005 |
| International Metal Foam Nordic AS | Professional & scientific | 2024 |
| International Metal Foam Norway AS | Professional & scientific | 2025 |
| International Mining Oil and Gas Solutions AS | Professional & scientific | 2017 |
| International Records Music Company AS | Information & communication | 2017 |
| International Sales and Services BV | Wholesale & retail | 1998 |
| International Technology Management AS | Professional & scientific | 2004 |
| International Trade Advisers AS Erik Holtedahl | Professional & scientific | 1989 |
| International Trading Group Itg AS | Wholesale & retail | 2012 |
| International Vintners AS | Wholesale & retail | 2020 |
| International Wealth Insurance AS | Financial services | 2020 |
| Internet Intelligence House Nordic | Information & communication | 2012 |
| Internet Service AS | Information & communication | 1995 |
| Internet Upside AS | Information & communication | 1997 |
| Internettdebut Da | Education | 2001 |
| Interni Oslo AS | Wholesale & retail | 1975 |
| Interno Bygg & Interiør AS | Construction | 2019 |
| Internova AS | Information & communication | 1996 |
| Internova Aviation - Marine - Surface AS | Wholesale & retail | 1993 |
| Interoil Argentina AS | Real estate | 2018 |
| Interoil Drilling Services AS | Mining & quarrying | 2019 |
| Interoil Exploration and Production ASA | Administrative & support | 2005 |
| Interoil Peru Holding AS | Administrative & support | 2011 |
| Interop AS | Information & communication | 2024 |
| Interpares AS | Professional & scientific | 1999 |
| Interpublic Norway AS | Professional & scientific | 2010 |
| Interpunct AS | | 2025 |
| Intersect AS | Information & communication | 2026 |
| Intersection AS | Wholesale & retail | 2009 |
| Intershop AS | Information & communication | 2002 |
| Intersikt AS | Information & communication | 2024 |
| Intersint AS | Professional & scientific | 2013 |
| Intersolia AS | Information & communication | 2022 |
| Interspeak AS | Professional & scientific | 2017 |
| Intersport Bogstadveien AS | Wholesale & retail | 1982 |
| Interstahler AS | Arts & recreation | 2024 |
| Interstate Media Ans | Information & communication | 1996 |
| Interstate Solutions LLC Nuf | Education | 2019 |
| Interstats AS | Information & communication | 2023 |
| Interstella Invest AS | | 2023 |
| Interstellar Capital AS | | 2018 |
| Intersystem AB | Wholesale & retail | 2014 |
| Intertekst AS | Arts & recreation | 2012 |
| Intertoll Norge AS | Construction | 2021 |
| Intertrade Shipping AS | Real estate | 1982 |
| Intertransport AS | Transport & logistics | 2015 |
| Interval AS | | 2019 |
| Intervalor AB Nuf | Professional & scientific | 2024 |
| Intervin AS | Wholesale & retail | 1966 |
| Intervista AS | Administrative & support | 2015 |
| Interwell Holding 1 AS | Mining & quarrying | 2021 |
| Interwell Holding 2 AS | Mining & quarrying | 2021 |
| Interyards AS | Wholesale & retail | 1995 |
| Intesta Consult AS | Professional & scientific | 2024 |
| Inthema AS | | 2021 |
| Inthemood Film AS | Information & communication | 2021 |