| Intelliserve AS | Sandnes | 2021 |
| Intellistream AS | Sola | 2023 |
| Intellitech AS | Oslo | 2016 |
| Intellitix Europe KFT | Hu-1143 Budapest | 2019 |
| Intellitix Limited | London Nw1 3Er | 2013 |
| Intello Group AS | Oslo | 2019 |
| Intelnord AS | Drammen | 2022 |
| Intelpro Intellectual Properties AS | Sætre | 2023 |
| Intelpro Investment Company AS | Sætre | 2023 |
| Intempus | Dk-2100 København Ø | 2015 |
| Intendit Aps | 8600 Silkeborg | 2002 |
| Intensjonell Utvikling AS | Trondheim | 2025 |
| Intentus AS | Søvik | 2008 |
| Inteq Solutions AS | Halden | 2026 |
| Inter Entertainment AS | Tromsø | 2024 |
| Inter Media Design Ans | Lundersæter | 2000 |
| Inter Pro Data AS | Oslo | 2012 |
| Inter-Consulting Europe (UK) Ltd | Oslo | 2007 |
| Intera Invest AS | Sandvika | 2019 |
| Interactive Innovations AS | Kristiansand S | 2010 |
| Interactive Intelligence, Inc. | Indiana 46204 | 2013 |
| Interactive Management Solutions Ltd | Rg27 8Ag | 2010 |
| Interactive Security International AB Nuf | Se-432 41 Varberg | 2025 |
| Interactive Software AS | Oslo | 1995 |
| Interago AS | Oslo | 2014 |
| Interago Holding AS | Oslo | 2024 |
| Interak AS | Nesøya | 2011 |
| Interatrade AS | Molde | 2016 |
| Interbe AS | Oslo | 2022 |
| Intercab AS | Kristiansand S | 2020 |
| Intercare AS | Ålesund | 2007 |
| Intercode AS | Tønsberg | 2018 |
| Interdata AS | Åsen | 1995 |
| Interestia AS | Oslo | 2000 |
| Interface Communication AS | Slattum | 2026 |
| INTERFERENS HOLOGRAFISK DA Museum Galleri Studio | Hamar | 1989 |
| Intergraph Belgium | Asker | 2014 |
| Intergraph Consulting PVT Ltd | 500003 Secunderabad A P 444 | 2008 |
| Intergraph Corporation | Asker | 2014 |
| Intergraph Norge AS | Sandnes | 1983 |
| Interhost AS | Oslo | 2010 |
| Interica Ltd | Gb-Tn22 1Ql Uckfield, East Sussex | 2016 |
| International Business Machines Corporation | 10504 New York | 2008 |
| International Business Machines Corporation Magyarorszagi KFT | Oslo | 2009 |
| International Business Machines of Belgium | Oslo | 2009 |
| International Business Machines SA | Es-28002 Madrid | 2017 |
| International Development Partners AS | Tønsberg | 2005 |
| International Distribution Service & Publishing Publishing Ans | Slemmestad | 1996 |
| International Records Music Company AS | Oslo | 2017 |
| Internet Intelligence House Nordic | Oslo | 2012 |
| Internet Marketing Consult AS | Tofte | 2002 |
| Internet Service AS | Oslo | 1995 |
| Internet Upside AS | Oslo | 1997 |
| Internetname IP Limited | Leigh On See Ss9 2Sa | 2011 |
| Internett Partner AS | Stabekk | 1995 |
| Internettopplysningen AS | Ski | 2004 |
| Internia AS | Drag | 2014 |
| Internova AS | Oslo | 1996 |
| Internsystem Consulting AS | Fredrikstad | 2012 |
| Interonline AS | Kokstad | 2006 |
| Interop AS | Oslo | 2024 |
| Interplay-Sports AS | Son | 2011 |
| Interprt AS | Trondheim | 2023 |
| Interra AS | Slependen | 2004 |
| Interrobang AS | Ski | 2024 |
| Interroll Nordic A/S | Dk-6260 Hvidovre | 2017 |
| Intersect AS | Oslo | 2026 |
| Intershare AS | Kristiansand S | 2021 |
| Intershop AS | Oslo | 2002 |
| Intersikt AS | Oslo | 2024 |
| Intersoft Management Systems AS | Lysaker | 1987 |
| Intersolia AS | Oslo | 2022 |
| Intersolution AS | Sarpsborg | 2016 |
| Interstate Media Ans | Oslo | 1996 |
| Interstats AS | Oslo | 2023 |
| Interweb Media AS | Hagan | 2015 |
| Intety AS | Tromsø | 2020 |
| Intheblue AS | Mauseidvåg | 2013 |
| Inthemood Film AS | Oslo | 2021 |
| Intility AS | Oslo | 2000 |
| Intime Nordic AS | Barkåker | 2021 |
| Intin AS | Førde | 2014 |
| Intoconsult AS | Borgen | 2018 |
| Intoinvest Holding AS | Borgen | 2012 |
| Intola Holding AS | Strømmen | 2022 |
| Intola Konsult AS | Strømmen | 2022 |
| Intostocks AS | Søgne | 2016 |
| Intoto AS | Kvinesdal | 2018 |
| Intracloud AS | Mo I Rana | 1995 |
| Intrahouse AS | Ålesund | 2000 |
| Intrahouse Data Centers AS | Kirkenes | 2021 |
| Intrahouse Glomfjord AS | Kirkenes | 2021 |
| Intrapods AS | Glomfjord | 2021 |
| Intrapoint AS | Oslo | 1999 |
| Intraport AS | Alta | 2015 |
| Intrapublish AS | Ålesund | 2000 |
| Intraspider AS | Ålesund | 2000 |
| Intrepix B.V. Nuf | Flatdal | 2025 |
| Intro Helse AS | Stavanger | 2023 |
| Intro Operating AS | Hjelmås | 2026 |