| Beerenberg Industri AS | Construction | 1995 |
| Beerkshare Honeyway AS | | 2025 |
| Beha Sport 2. Etg AS | Real estate | 2008 |
| Beha Sport AS | Wholesale & retail | 1998 |
| Beha-Hedo Marine AS | Manufacturing | 1988 |
| Beha-Kvartalet Eiendom AS | Real estate | 2018 |
| Bergsli AS | Wholesale & retail | 2012 |
| Berten Holding AS | | 2011 |
| Bertrand Holding AS | | 2023 |
| Betong Og Anleggsteknikk AS | Transport & logistics | 2022 |
| Bi-A AS | Financial services | 2005 |
| Bi-T AS | Financial services | 2005 |
| Biedermann AS | Professional & scientific | 2021 |
| Bilbingen AS | Wholesale & retail | 2018 |
| Bildeler Porsgrunn AS | Other services | 2001 |
| Bildesign AS | Wholesale & retail | 2005 |
| Bilfinger Norway AS | Manufacturing | 2005 |
| Bilhav AS | Wholesale & retail | 2026 |
| Bilmateriell Grenland AS | Wholesale & retail | 2002 |
| Bilmg Holding AS | Wholesale & retail | 2022 |
| Bilutleie Grenland AS | Administrative & support | 1995 |
| Bio Jæren AS | Manufacturing | 2022 |
| Birkhans AS | Wholesale & retail | 2011 |
| Birtedalen Utvikling AS | Real estate | 2020 |
| Biti Da | Wholesale & retail | 1997 |
| Bittelillevennen Da | Wholesale & retail | 2005 |
| Bizzy Hamburgerbar Ans | Hospitality | 1989 |
| Bjerketvedt Ferdigplen AS | Agriculture & fishing | 1994 |
| Bjønnveien 23 AS | Real estate | 2015 |
| Bjønnveien Holding AS | Real estate | 2014 |
| Bjønnveien Næringspark AS | Real estate | 2017 |
| Bjørka Invest AS | Professional & scientific | 2015 |
| Bjørkedal Invest AS | Financial services | 2005 |
| Bjørkedal Montessori Skole SA | Education | 2010 |
| Bjørkly Holding AS | Real estate | 2005 |
| Bjørkøya Hytter AS | Real estate | 2020 |
| Bjørndalsjordet 1 AS | Real estate | 2024 |
| Bjørndalsveien 4 AS | Real estate | 2006 |
| Bjørns Reklame Ans | | 1994 |
| Bjørnstad Eiendom AS | Real estate | 2026 |
| Bjørntvedt Holding AS | Real estate | 2007 |
| BK Investering AS | | 2022 |
| Bko Holding AS | Hospitality | 2017 |
| Blaatime AS | Professional & scientific | 2018 |
| Blekebakkveien Eiendom AS | Real estate | 2005 |
| Blend Or Cut AS | Other services | 2021 |
| Blink Fysioterapi AS | Health & social care | 2023 |
| Blink Helse AS | Health & social care | 2021 |
| Blossome AS | Other services | 2024 |
| Blue Corner Grill Da | Hospitality | 2003 |
| Blue Power AS | Administrative & support | 2021 |
| Blue Power Holding AS | Administrative & support | 2021 |
| Blå Kurer AS | Transport & logistics | 1991 |
| Bne Holmestrand Bolig AS | Real estate | 2018 |
| Bo-Partner AS | Real estate | 2006 |
| Boatx AS | Wholesale & retail | 2023 |
| Bolig & Fasade AS | Construction | 2025 |
| Boligringen AS | Real estate | 2007 |
| Bonafide AS | Real estate | 2005 |
| Borgeraas & Myrholt AS | Professional & scientific | 2023 |
| Borgeåsvg 11 AS | Financial services | 2013 |
| Borsodi Holding AS | | 2022 |
| Bortech AS | Construction | 1992 |
| Borutstyr AS | Wholesale & retail | 2021 |
| Bos Utbygging AS | Real estate | 2019 |
| Bostad Holding AS | | 2026 |
| Bosøk AS | Professional & scientific | 2025 |
| BPT AS | Other services | 2024 |
| Brada Da | Wholesale & retail | 2005 |
| Brage Lykke AS | Real estate | 2020 |
| Braki Invest AS | | 2023 |
| Brandbu Helsebygg AS | Health & social care | 1997 |
| Bratsberg AS | Real estate | 2007 |
| Bratsberg Eiendom Drift AS | Real estate | 2007 |
| Bratsberg Holding AS | Real estate | 2021 |
| Bratsberg Næring AS | Real estate | 2013 |
| Bratsberg Næringseiendom AS | Real estate | 2014 |
| Brattås Utbygging AS | Real estate | 2019 |
| Bredbånds Spesialisten Ans | Information & communication | 2001 |
| Breidablikklia Utbygging AS | Real estate | 2022 |
| Brenna 7 AS | Real estate | 2021 |
| Brenna 8 AS | Real estate | 2018 |
| Brevik Bolig AS | | 2021 |
| BRH Holding AS | Wholesale & retail | 2005 |
| Brillane AS | | 2025 |
| Brodering AS | Wholesale & retail | 2019 |
| Brokelandsheia Øst 2 AS | Real estate | 2014 |
| Brua Servicenter AS | Wholesale & retail | 2005 |
| Brubakken AS | Manufacturing | 1974 |
| Brubakken Holding AS | Wholesale & retail | 2008 |
| Brubakken Rental AS | Administrative & support | 2020 |
| Bryns Blomster AS | Agriculture & fishing | 1994 |
| Bryns Eiendom AS | Real estate | 1987 |
| Brødrene Andersen Stillasutleie AS | Administrative & support | 1999 |
| Brødrene Evensen Eiendom AS | Real estate | 2022 |
| Brødrene Evensen Holding AS | Real estate | 2022 |
| Brødrene Hansen Eiendom AS | Construction | 1999 |
| Brødrene Hansen Transport AS | Transport & logistics | 1998 |
| Brødrene Johnsen Invest AS | Construction | 2005 |
| Brødrene Lauritsen Eiendom AS | Real estate | 2014 |