| Autonomica AS | Information & communication | 2024 |
| Avanti Engineering Holding AS | Financial services | 2008 |
| Avensa AS | Information & communication | 2022 |
| Awati AS | Information & communication | 2021 |
| Axelsen Eiendom AS | Real estate | 1996 |
| Axelssons Takservice AS | Construction | 2024 |
| B-G Entreprenør AS | Construction | 2008 |
| B. Beauty AS | Other services | 2019 |
| B.K Bygg 1 AS | Real estate | 2015 |
| B3 Service AS | Construction | 2024 |
| Bab Transport & Maskin AS | Transport & logistics | 2007 |
| Babettes Compagniet Da | Hospitality | 2011 |
| Bakeriet Invest AS | Real estate | 2005 |
| Bakeriet Mo I Rana AS | Manufacturing | 1988 |
| Bakern Mo I Rana AS | Manufacturing | 2009 |
| Bakst Holding AS | Manufacturing | 2009 |
| Bankbygg Mo AS | Real estate | 2021 |
| Barnehagen Småtroll AS | Education | 2018 |
| Bayern Auto AS | Wholesale & retail | 2012 |
| Bazar AS | Real estate | 2018 |
| BB19 Holding AS | Real estate | 2019 |
| BBG Eiendom AS | Real estate | 2014 |
| Bbrk Holding AS | | 2022 |
| Beauty Lounge by Susanne AS | Other services | 2022 |
| Bechs Hotel & Camping AS | Hospitality | 1990 |
| Bedre Økonomitjenester AS | Professional & scientific | 2013 |
| Bedriftsgata 7 AS | Real estate | 2024 |
| Beld Invest AS | Wholesale & retail | 2021 |
| Beleggsenteret AS | Construction | 1996 |
| Bennettbygget AS | Real estate | 2007 |
| Benz Invest AS | | 2021 |
| Bergene Holding AS | | 2022 |
| Bergets Holding AS | Real estate | 2022 |
| Bernhard Olsen AS | Manufacturing | 1990 |
| Betongflytebrygger AS | Manufacturing | 1994 |
| Bevi Eiendom AS | Real estate | 2023 |
| Bil Pluss Mo I Rana AS | Other services | 2001 |
| Bilalliansen AS | Wholesale & retail | 1998 |
| Bilalliansen Eiendom AS | Real estate | 2013 |
| Bimbo Veikro AS | Hospitality | 2002 |
| Binn Eiendom AS | Real estate | 2014 |
| Bio Carbon Nor AS | Wholesale & retail | 2018 |
| Bioentreprenør AS | Manufacturing | 2007 |
| Biskop Bangs GT. AS | Real estate | 2018 |
| Bjelkelaget AS | Construction | 2023 |
| Bjerkeli Invest AS | Financial services | 2013 |
| Bjynnvika AS | Real estate | 2011 |
| Björklund Pharma AS | Wholesale & retail | 2014 |
| Bjørklund Mek Verksted AS | Manufacturing | 1996 |
| Bjørnådal AS | Wholesale & retail | 2009 |
| Black Lotus Invest AS | | 2021 |
| Blackwater AS | Professional & scientific | 2011 |
| Blikk Utvikling AS | Real estate | 2021 |
| Blomsterbua Selfors AS | Wholesale & retail | 2016 |
| BLP Holding AS | | 2021 |
| Bmi Holding AS | Agriculture & fishing | 2019 |
| Bo Møbler AS | Wholesale & retail | 1986 |
| Bo Service AS | Administrative & support | 2025 |
| Bohag AS | Wholesale & retail | 1993 |
| Bohlin Bolig AS | Real estate | 2019 |
| Bohlin Eiendom AS | Real estate | 2014 |
| Bohlin Gruppen AS | Real estate | 2013 |
| Bohlin Holding AS | | 2021 |
| Bohlin Invest AS | Professional & scientific | 2021 |
| Bohlin Maskin & Transport AS | Transport & logistics | 2014 |
| Bohlin Maskinutleie AS | Administrative & support | 2011 |
| Bohlin Ranenget Eiendom AS | Real estate | 2014 |
| Boligservice Helgeland AS | Real estate | 2025 |
| Bolna AS | Financial services | 1998 |
| Borealex AS | Professional & scientific | 2023 |
| Bork Mo AS | Real estate | 2010 |
| Bosans AS | Professional & scientific | 2018 |
| Bossmo AS | Real estate | 2021 |
| Botn Bygg AS | Real estate | 2021 |
| Botn Eiendomsselskap AS | Real estate | 2022 |
| Botn Elektro AS | Construction | 2021 |
| Botn Holding AS | Construction | 2021 |
| Brattbakkhei Holding AS | Arts & recreation | 2020 |
| Bratthenget AS | Professional & scientific | 2017 |
| Bre Eiendom AS | Real estate | 2018 |
| Brede Nutrition AS | Wholesale & retail | 2025 |
| Breiland Holding AS | | 2026 |
| Breilia Eiendom AS | Real estate | 2016 |
| Breyer Invest AS | | 2025 |
| Brida Eiendom AS | Real estate | 1999 |
| Brilliant Investing AS | | 2019 |
| Brutus Eiendom AS | Real estate | 2011 |
| Brødrene Helland Ans | Transport & logistics | 1994 |
| Brúheimr AS | Professional & scientific | 2025 |
| BT Vika AS | Wholesale & retail | 2005 |
| BTK Eiendom AS | | 2006 |
| Build Up AS | Professional & scientific | 2019 |
| Building the Future AS | Construction | 2022 |
| Building X AS | Real estate | 2018 |
| Bunnpris Båsmoen AS | Wholesale & retail | 1992 |
| Busstopp 9 AS | Real estate | 2022 |
| Bustnes Bygg AS | Construction | 2024 |
| Butikkdrift Ørjan Torbergsen AS | Wholesale & retail | 2022 |
| Byggcon Helgeland AS | Real estate | 2021 |
| Byggmester Bernhard Strandvoll Ans | Construction | 1994 |