| Bunnpris Olderskog AS | Wholesale & retail | 2014 |
| Bygg-Tech Mosjøen AS | Construction | 2012 |
| Bysprinten AS | Arts & recreation | 2021 |
| C M Havigsgt. 12 AS | Real estate | 2003 |
| Cafebaren 2 AS | Hospitality | 2019 |
| Call-It AS | Administrative & support | 2008 |
| Capture AS | Information & communication | 2021 |
| Carpe AS | Financial services | 2014 |
| Causa Nord AS | Professional & scientific | 2017 |
| Cavo Eiendom AS | Construction | 2014 |
| Centralen AS | Wholesale & retail | 2019 |
| Chaplin AS | Wholesale & retail | 1993 |
| CHD Holding AS | | 2025 |
| CHD Visual Effects AS | Information & communication | 2023 |
| Chemitech Consulting AS | Professional & scientific | 2014 |
| Cico Holding AS | Financial services | 2017 |
| Classic Cars Mosjøen AS | Real estate | 2010 |
| Cloudrunner AS | | 2026 |
| CM Havigs Gate 39-41 AS | Real estate | 2015 |
| CM Havigsgt 15 AS | | 1997 |
| Cockerel Games AS | Manufacturing | 2023 |
| Conesso AS | Real estate | 1995 |
| Contrast Marketing Group AS | Professional & scientific | 2025 |
| Cornershop Da | Wholesale & retail | 2009 |
| Cristina Renhold AS | Administrative & support | 2025 |
| Dagsvik Holding AS | Real estate | 2021 |
| Dalamo Eiendom AS | Real estate | 2021 |
| Daleng Og Sønner AS | Transport & logistics | 2020 |
| Daneljordet 13 AS | Real estate | 2020 |
| Daneljordet 15 AS | Transport & logistics | 2017 |
| Daneljordet 2-4 AS | Real estate | 2025 |
| Dantes AS | Financial services | 2005 |
| David Kinsella Productions AS | Information & communication | 2008 |
| DDS Holding AS | | 2025 |
| De-Sign AS | Professional & scientific | 2025 |
| Dele Health Tech AS | Information & communication | 2011 |
| Demmy AS | Construction | 2022 |
| Den Røde Tråd AS | Manufacturing | 2017 |
| Digipilot AS | Information & communication | 2013 |
| Dolstad Barnehage AS | Education | 2015 |
| Dolstad Eiendom AS | Real estate | 1999 |
| Dolstadlia Boliger AS | Real estate | 2017 |
| Dreamscores AS | Arts & recreation | 2015 |
| Drevjavassdragets Forvaltningslag SA | Real estate | 2018 |
| Drevland Eiendom AS | Real estate | 1985 |
| Drevland Holding AS | Real estate | 2008 |
| Driv Media AS | Information & communication | 2022 |
| Dyrhaug Motorservice AS | Manufacturing | 2026 |
| Dyrlegene Mosjøen AS | Professional & scientific | 2020 |
| E-Skjønnhetsstudio AS | Other services | 2024 |
| E. NT Utbygging AS | Construction | 2011 |
| Easyframe AS | Professional & scientific | 2024 |
| Eberg Lås & Sikkerhet AS | Construction | 2021 |
| Egedesgate 28 AS | Real estate | 2007 |
| Egedesgt 38 Ans | Real estate | 1994 |
| Eiendom KR Mosjøen AS | Real estate | 2012 |
| Eiendom Nor AS | Real estate | 1991 |
| Einron Eiendom AS | Real estate | 2015 |
| Elament AS | Information & communication | 2024 |
| Elbrus AS | Financial services | 2008 |
| Elektrikern Mosjøen AS | Construction | 2003 |
| Elektroland AS | Wholesale & retail | 2005 |
| Ellen Style AS | Other services | 2018 |
| Elmar Svendsen AS | Construction | 1995 |
| Elmar Svendsen Eiendom AS | Real estate | 2020 |
| Emira Eiendom AS | Real estate | 1995 |
| Endodontist Veronika Edvardsen AS | Health & social care | 2022 |
| Enduro Eiendom AS | Real estate | 2005 |
| Energifestivalen AS | Arts & recreation | 2026 |
| Enjoy Holding AS | | 2025 |
| Enjoy Mosjøen AS | Real estate | 2014 |
| Entreprenør Sten Turmo AS | Construction | 2008 |
| Entreprenør Team AS | Construction | 1999 |
| Entreprenørteam Eiendom AS | Real estate | 2007 |
| Entrepretor AS | Construction | 1994 |
| Entrepretor Eiendom AS | Real estate | 2007 |
| Equinox Invest AS | Transport & logistics | 2014 |
| Erawan Market Mosjøen AS | Wholesale & retail | 2023 |
| Erlita AS | Professional & scientific | 2026 |
| Eslotter Holding AS | | 2007 |
| Eurobit AS | Wholesale & retail | 2005 |
| Eurot AS | Real estate | 2005 |
| Fabrikkutsalget Mosjøen AS | Wholesale & retail | 1994 |
| Fager Bolig AS | Real estate | 2021 |
| Fagertoppen Holding AS | Administrative & support | 2021 |
| FBN Holding AS | Real estate | 2011 |
| Fearnleys Gate 25 AS | Real estate | 2020 |
| Fearnleysgt 7/9 AS | Real estate | 1994 |
| Festspillene Helgeland AS | Arts & recreation | 2019 |
| FG 23 Eiendom AS | Real estate | 2021 |
| Fiemar AS | Financial services | 2016 |
| Finnskoggata 37 AS | Real estate | 2021 |
| Firkløveret Holding AS | Professional & scientific | 2020 |
| Fjellskog Invest AS | | 2026 |
| Flagholmen Invest AS | | 2006 |
| Forsjord Anlegg Og Maskin Service Ans | Manufacturing | 2007 |
| Forsjord Fiskerivilla | | 1997 |
| Frank Brubakk Transport AS | Transport & logistics | 2006 |
| Franks Holding AS | Professional & scientific | 1998 |
| Fredlund Invest AS | Real estate | 2024 |