| Benkin AS | | 2026 |
| Bentsen Maskin AS | Construction | 2023 |
| Bentzen Holding AS | Real estate | 1988 |
| Berg Eiendom AS | Real estate | 1991 |
| Berg Service A/S | Real estate | 1978 |
| Bergan Maskinsalg Hønefoss AS | Wholesale & retail | 2025 |
| Bergborring AS | Real estate | 2012 |
| Bergen Butikkeiendom Godvik AS | Real estate | 2005 |
| Bergen Butikkeiendom Ulset AS | Real estate | 2021 |
| Bergen Butikkeiendom Valle AS | Real estate | 2017 |
| Bergen Handelsbygg Ulset AS | Real estate | 2014 |
| Berget-Holding AS | Real estate | 2014 |
| Bergheim Forvaltning AS | | 2025 |
| Bergheim Invest AS | Education | 2005 |
| Bergheim Utvikling AS | | 2025 |
| Berglia Holding AS | Real estate | 2010 |
| Bergsveien 6 AS | Real estate | 2022 |
| Bergwerk AS | Administrative & support | 2016 |
| Berntsen Plan & Oppmåling AS | Professional & scientific | 2012 |
| Besenur Invest AS | | 2008 |
| Best Kids AS | Wholesale & retail | 2008 |
| Best Wang AS | Professional & scientific | 2011 |
| Bikolibri Holding AS | Financial services | 2005 |
| Bil Abc AS | Wholesale & retail | 2024 |
| Bil Og Hengerservice AS | Manufacturing | 1999 |
| Bil Og Transport Konsulentene Da | Wholesale & retail | 2004 |
| Bil Park Ans | Transport & logistics | 2001 |
| Bilben Taksering AS | Professional & scientific | 2014 |
| Bilco Hønefoss AS | Wholesale & retail | 1993 |
| Bildeler Ringerike AS | Wholesale & retail | 1989 |
| Bildemontering Ringerike AS | Water & waste | 2011 |
| Bilgården AS | Real estate | 1955 |
| Bilgården AS | Wholesale & retail | 2018 |
| Bilhuset Viken AS | Other services | 2018 |
| Billingstadsletta 48 AS | Real estate | 2018 |
| Bilpleiesenteret AS | Other services | 2009 |
| Bilpleiesenteret Eiendom AS | Other services | 1996 |
| Bilverk AS | Other services | 2025 |
| Bintang AS | Professional & scientific | 2019 |
| Biomangfold Landbruk SA | Manufacturing | 2021 |
| Biometric Games AS | Information & communication | 2011 |
| Bissevov AS | Other services | 2015 |
| Bitmagic AS | Information & communication | 2007 |
| Bjerke & Co. Eiendomsselskap AS | Real estate | 2003 |
| Bjerke Landskap AS | Administrative & support | 2022 |
| Bjerkeli Maskin Og Utleie AS | Administrative & support | 2006 |
| Bjerkseter Consulting AS | Information & communication | 2024 |
| Bjørkedalsvegen 4 AS | Real estate | 1997 |
| Bjørndal Butikkeiendom AS | Real estate | 2006 |
| Bjørnrud AS | Information & communication | 2022 |
| Bjørseth Holding AS | Real estate | 2007 |
| Blanche Beauty AS | Other services | 2022 |
| Blum Norge AS | Wholesale & retail | 2022 |
| Blåbærskogen Barnehage SA | Education | 2002 |
| BM Bil & MC AS | Wholesale & retail | 2022 |
| BM Bil Holding AS | Real estate | 2022 |
| BM Næringseiendom AS | Real estate | 2022 |
| BMH Eiendom AS | Real estate | 2011 |
| BMH Utvikling AS | | 2026 |
| Bo Og Omsorg Eiendom AS | Administrative & support | 2016 |
| Bodø Butikkeiendom AS | Real estate | 2007 |
| Bodø Butikkeiendom Hunstad AS | Real estate | 2009 |
| Boligassist AS | Administrative & support | 2018 |
| Boligblikk AS | Real estate | 2014 |
| Bolkan Trans Hønefoss AS | Transport & logistics | 2013 |
| Bomer Ringerike AS | Professional & scientific | 2021 |
| Bomiljø Ringerike AS | Wholesale & retail | 2003 |
| Bondehagen Motor Mekk Og Moro AS | Wholesale & retail | 2020 |
| Bonnie AS | Information & communication | 2021 |
| Borgar Holding AS | Financial services | 2017 |
| Borger AS | Health & social care | 2014 |
| Borger Bad AS | Real estate | 2005 |
| Borgerenga AS | Financial services | 2005 |
| Bovieran Ringerike AS | Real estate | 2021 |
| BR Tjenester AS | Construction | 2022 |
| Braata Verktøy AS | Professional & scientific | 2025 |
| Braathen Eiendom AS | Real estate | 1975 |
| Brager AS | Transport & logistics | 2005 |
| Brager Bil AS | Administrative & support | 2016 |
| Braka AS | Real estate | 2013 |
| Brandbu Eiendom AS | Real estate | 2007 |
| Brann Og Lås AS | Professional & scientific | 2021 |
| Brann Og Låsservice AS | Administrative & support | 1999 |
| Braseth Invest AS | Professional & scientific | 2017 |
| Brasserie Fengselet AS | Hospitality | 2008 |
| Bratvold Boligventilasjon AS | Construction | 2020 |
| Bratvold Boligventilasjonsservice AS | Construction | 2025 |
| Breienmarka Skog Ans | Agriculture & fishing | 1995 |
| Breivassbu AS | Real estate | 2013 |
| Brix Technology AS | Administrative & support | 2000 |
| Brix.Green AS | Manufacturing | 2013 |
| Brolavi Management AS | Professional & scientific | 2014 |
| Bruget Hønefoss AS | Real estate | 2012 |
| Bruktberget AS | Wholesale & retail | 2012 |
| Bruland Energi AS | Energy | 2001 |
| Bruvik Utvikling AS | Real estate | 2016 |
| Bryggerikjelleren AS | Hospitality | 2019 |
| Brødr Helgesens Eftf AS | Construction | 1984 |
| Brønn Og Energiboring Buskerud AS | Construction | 2002 |
| Brønnspesialisten AS | Professional & scientific | 2022 |