| NH Maskin AS | Kjerrgarden | 1996 |
| NH Melhusbygg AS | Melhus | 2007 |
| Nh-Profil AB Nuf | Oslo | 2016 |
| Nhe Holding AS | Kleppestø | 2017 |
| NHH Holding AS | Straumgjerde | 2023 |
| NHM Bane AS | Bjørkelangen | 2018 |
| Niansi AS | Steinberg | 2023 |
| Nibe Holding AS | Hokksund | 2015 |
| Nibo Trackwelding Team AB Nuf | Se-432 92 Varberg | 2014 |
| Nic Jacobsen Entreprenør AS | Kleppestø | 1990 |
| Nice Design Aps | Dk-6740 Bramming | 2024 |
| Niclas Börjesson | Se-672 93 Årjang | 2017 |
| Nico Blikk & Tak AS | Kristiansand S | 2014 |
| Nico Bygg AS | Randaberg | 2024 |
| Nico Holding AS | Oslo | 2005 |
| Nico Håndverk Malermester Sten Yttervik AS | Fauske | 1990 |
| Nicolaysen Betong AS | Søgne | 2024 |
| Nicomarie Invest AS | Hidrasund | 2019 |
| Nidaros Betong AS | Trondheim | 2022 |
| Nidaros Betong Holding AS | Trondheim | 2022 |
| Nidaros Betongsaging AS | Trondheim | 2025 |
| Nidaros Eiendomsservice AS | Trondheim | 2018 |
| Nidaros Elektro AS | Ranheim | 2018 |
| Nidaros Glass Og Montasje AS | Trondheim | 2020 |
| Nidaros Mur&Flis AS | Tiller | 2026 |
| Nidaros Murerservice AS | Vikhammer | 2012 |
| Nidaros Mursystem AS | Buvika | 2015 |
| Nidaros Vedlikeholdsservice AS | Trondheim | 2005 |
| Nidaros VVS AS | Saksvik | 2023 |
| Nidarosklima AS | Trondheim | 2023 |
| Nidarvoll Byggservice AS | Trondheim | 2008 |
| Nidco Solutions AS | Tolvsrød | 2024 |
| Nidco Solutions Nuf | Tolvsrød | 2014 |
| Nidelv Elektro AS | Heimdal | 2025 |
| Nidelven Bygg AS | Ranheim | 2014 |
| Nidelven VVS AS | Trondheim | 2020 |
| Nider AS | Sellebakk | 2023 |
| Nidheim Industri AS | Trondheim | 2021 |
| Niels F Danielson AS | Kråkstad | 1982 |
| Niels Kristian Veggerby | Dk - 9240 Nibe | 2015 |
| NIELS1 AS | Bangsund | 2023 |
| Nielsen Bygg Da | Oslo | 1991 |
| Nielsen Products Aps | Dk-6040 Egtved | 2012 |
| Nielsen VVS Og Bygg AS | Bergen | 2025 |
| Nig AS | Kristiansand S | 2010 |
| Nigomáhtte AS | Skibotn | 2024 |
| Nijo AS | Surnadal | 2012 |
| Nijo Holding AS | Asker | 2024 |
| Nijo Invest AS | Gamle Fredrikstad | 2013 |
| Nikkeby Multiservice AS | Nikkeby | 2020 |
| Niklas Bekkevold AS | Steinberg | 2022 |
| Niklas Bygg AS | Frogner | 2018 |
| Niklas Eriksen AS | Aurskog | 2021 |
| Niko Entreprenør AS | Fjellhamar | 2026 |
| Nikolaisen Elektro AS | Bø I Vesterålen | 2024 |
| Nikolaisen Maskin AS | Røyse | 2024 |
| Nikolaisen Naturstein AS | Holum | 2018 |
| Nikolaus Izdinsky | Skarnes | 2007 |
| Nikolaysen Rørservice AS | Siggerud | 2026 |
| Niliv AS | Steinkjer | 2021 |
| Nilmar AS | Mauseidvåg | 2018 |
| Nils Berg Invest AS | Oslo | 2005 |
| Nils Fauske AS | Lillehammer | 2016 |
| Nils H Sæther AS | Valderøya | 1986 |
| Nils Inge Tjelta AS | Tjelta | 1992 |
| Nils Kaldahl Anlegg & Transport AS | Nord-Statland | 2004 |
| Nils Kloster AS | Kvinesdal | 1981 |
| Nils Kristoffersen AS | Haslum | 1970 |
| Nils Oma Maskin AS | Bryne | 2018 |
| Nils Petter Øie AS | Hjelset | 2019 |
| Nils Reime Maskin AS | Nærbø | 2005 |
| Nils Vetle Medhus AS | Røldal | 2026 |
| Nils Vågslid AS | Edland | 2008 |
| Nils Åge Strømsjordet Og Sønn AS | Nord-Torpa | 2026 |
| NILS1 Bygg AS | Rørvik | 2024 |
| Nilsane AS | Utvik | 2022 |
| Nilsen & Co AS | Grimstad | 1972 |
| Nilsen & Kjæraas Bygg AS | Sandefjord | 2025 |
| Nilsen & Rismyr Montasje Da | Årnes | 1999 |
| Nilsen & Sandvik AS | Fredrikstad | 2020 |
| Nilsen & Solberg Byggservice AS | Mjølkeråen | 2014 |
| Nilsen & Staal Bygg AS | Tistedal | 2025 |
| Nilsen & Sture Betong AS | Kleppestø | 2004 |
| Nilsen Bygg Kragerø AS | Kragerø Skjærgård | 2016 |
| Nilsen Bygg Og Drift AS | Arnatveit | 2024 |
| Nilsen Bygg Og Vedlikehold AS | Rypefjord | 2025 |
| Nilsen Eiendom AS | Vegårshei | 1996 |
| Nilsen Elektro AS | Horten | 1990 |
| Nilsen Elektro Installasjon AS | Mo I Rana | 2013 |
| Nilsen Entreprenør AS | Vegårshei | 2021 |
| Nilsen Flis Og Håndverkservice AS | Bodø | 2018 |
| Nilsen Frys & Kjøleteknikk AS | Kristiansund N | 2001 |
| Nilsen Hytteutvikling AS | Gvarv | 2020 |
| Nilsen Kran Og Industriservice AS | Gjøvik | 2013 |
| Nilsen Kulde AS | Kristiansund N | 2024 |
| Nilsen Malerservice AS | Rakkestad | 2022 |
| Nilsen Marin Og Maskin AS | Kleppestø | 2022 |
| Nilsen Maskin & Bygg AS | Sande I Vestfold | 2026 |
| Nilsen Maskin AS | Vegårshei | 1995 |
| Nilsen Og Hartveit Tømrerfirma Da | Skien | 2003 |