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| Ipeople AS | Stavanger | 2011 |
| Ipg Contact Solutions NV | 1000 Brussel | 2018 |
| Ipi AS | Stavanger | 2008 |
| Ipl Information Processing Limited | Grove Street Bath Bai 5Lr | 2011 |
| Ips Rangering AS | Langhus | 2013 |
| IPV4 31 Ltd Nuf | N146Qh, London, Southgate | 2010 |
| IPV6 32 Ltd Nuf | N146Qh, London, Southgate | 2011 |
| Iqc AS | Tjøme | 2016 |
| Iras AS | Lillestrøm | 2025 |
| Irent AS | Fyllingsdalen | 2019 |
| Iris Aviation Leasing Limited | D02R296 Dublin 2 | 2019 |
| Iris Thaumas Ltd | Mt-Stj 4011 St Julian'S | 2018 |
| Irish Tourist Board | Oslo | 1999 |
| Irlands Turistkontor | Oslo | 2000 |
| Irma's Vask & Fix AS | Alta | 2015 |
| Irman Development Association Ekonomiske Forening | Stavanger | 2002 |
| Irs Recruitment | Oslo | 2012 |
| Irute Travel Norway AS | Lysaker | 2026 |
| Isa Renhold AS | Drammen | 2020 |
| Isabella Management AS | Setskog | 2009 |
| Isabelle Skontorp Consultor Sosiedad Limitada | Es-03729 Liber Alicante | 2019 |
| Isaksen & Seim Evensen Da | Oslo | 2003 |
| Isaksen Eiendom AS | Sørreisa | 2002 |
| Isaksen Vedlikehold AS | Skien | 2011 |
| Isanor AS | Oslo | 2021 |
| Isar Aerospace Sweden AB | Se-981 37 Kiruna | 2022 |
| Isarpsborg AS | Sarpsborg | 2001 |
| Ischebeck Nordic AS | Spydeberg | 2011 |
| Isdalen Agentur Da | Bergen | 2022 |
| Isdalen Green Transport AS | Rådal | 2014 |
| Ishavsluft AS | Birtavarre | 2024 |
| Isi Renhold AS | Alta | 2003 |
| Islandspesialisten AS | Moss | 2011 |
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| Isoleringsmaskinen Norge AS | Heimdal | 2024 |
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| Isotank AS | Drammen | 2026 |
| Isotek AS | Helleland | 2012 |
| Isps Terminal Sjursøy Nord AS | Oslo | 2005 |
| Iss Facility Services AS | Oslo | 1952 |
| Iss Holding AS | Oslo | 2007 |
| Iss Industri & Skadeservice AB | Se-653 50 Karlstad | 2002 |
| Iss Management AS | Oslo | 2007 |
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| Issy AS | Drammen | 2017 |
| Istep AS | Oslo | 2024 |
| Isverk Holding AS | Drammen | 2023 |
| Ita Travel AS | Bergen | 2022 |
| Italia Partner AS | Bekkestua | 2020 |
| Italiamo AS | Fredrikstad | 2017 |
| Italic Managed Solutions Ltd | Chemsford Cm1 1Sw | 2015 |
| Itaste AS | Bergen | 2024 |
| Itconnect Scandinavia AB | Se-451 43 Uddevalla | 2018 |
| Itec Utleie AS | Larvik | 2022 |
| Iterago AS | Oslo | 2026 |
| Iterio AB | Se-118 60 Stockholm | 2019 |
| Itg Holding AS | Rødberg | 2024 |
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| Itreco Da | Limingen | 2001 |
| Itrollheimen AS | Rindal | 2014 |
| Its Professionals (1004) Limited | Gb-Thetford, Ip25 7Qq | 2019 |
| Itub AS | Ålesund | 2010 |
| Iussisti AS | Hafrsfjord | 2023 |
| Iussisti Invest AS | Hafrsfjord | 2023 |
| Iutleie AS | Samuelsberg | 2022 |
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| Ivaretatt AS | Stavanger | 2013 |
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| Ivema Holding AS | Trondheim | 2006 |
| Iver Westerlund AS | Trondheim | 2023 |
| Iver Workplace AB | Se-721 30 Västerås | 2021 |
| Ivers AS | Meråker | 2019 |
| Iveta Renhold AS | Svinndal | 2024 |
| Ivetas Service AS | Noresund | 2024 |
| Iveti Oppdrag AS | Porsgrunn | 2024 |
| Ivy AS | Oslo | 2024 |
| Iwannago AS | Rennesøy | 2022 |
| Iwg Holdings (Norway) AS | Oslo | 2021 |
| Ixos Software Denmark Filial Af Ixos Software (International) AG Schweiz | 2500 Biel-Bienne 6 | 2000 |
| Izabela Rens AS | Oslo | 2026 |
| Iziquick Produkter AS | Lalm | 2011 |
| Iå Invest AS | Skei I Jølster | 2014 |
| J & J Barlund Holding AS | Lillehammer | 2024 |
| J & M Vedlikehold Da | Rasta | 2001 |
| J & R Utleie Og Tjenester AS | Surnadal | 2026 |
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| J Haukåssveen AS | Sjusjøen | 2003 |
| J Johansen Transport AS | Trofors | 2014 |
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| J&E Sports | 5348La Oss | 2016 |
| J&J Torres Consulting AS | Rasta | 2019 |
| J&R Event AS | Narvik | 2026 |
| J&T Homeservice AS | Tromsø | 2023 |
| J-Byggvakt AS | Verdal | 2024 |
| J-E.T.T AS | Varangerbotn | 2024 |
| J. Berstad Eiendom 2 AS | Bergen | 2023 |