| BFT AS | Real estate | 2013 |
| Bij Holding AS | Professional & scientific | 2019 |
| Bil & Invest AS | Real estate | 2016 |
| Bil Direkte AS | Wholesale & retail | 2015 |
| Bilyard AS | Wholesale & retail | 2025 |
| Binzel Norge AS | Wholesale & retail | 1995 |
| Bitflow Solutions AS | Information & communication | 2017 |
| BJ Borgersen AS Takstforretning | Real estate | 1984 |
| Bjarv AS | | 2003 |
| Bjerkedok Holding AS | Real estate | 2013 |
| Bjørg's Cafe AS | Hospitality | 2005 |
| Bjørn Borgersen Eiendom AS | Real estate | 2005 |
| Bjørn Borgersen Holding AS | Real estate | 2005 |
| Bjørnerud Invest AS | Professional & scientific | 2020 |
| Bjørnerud Takst AS | Professional & scientific | 2016 |
| BK Varmeteknikk AS | Construction | 2011 |
| BL Media AS | Information & communication | 2004 |
| Bodutleie Avdeling Drammen AS | Real estate | 2019 |
| Bodutleie Avdeling Loesmoen AS | Administrative & support | 2025 |
| Bogen Revisjon AS | Professional & scientific | 2023 |
| Bolig-Service AS | Construction | 2012 |
| Boosterpakker AS | Wholesale & retail | 2024 |
| Borge Butikk AS | Wholesale & retail | 1989 |
| Borge Installasjon AS | Construction | 1989 |
| Bovs - Bygg Og Våtromsspesialisten AS | Real estate | 2024 |
| Box Boligstyling AS | Professional & scientific | 2017 |
| BR Blikk AS | Construction | 2017 |
| BR Nordic Trading AS | Wholesale & retail | 2025 |
| Bra Rør AS | Construction | 2021 |
| Braleker AS | Wholesale & retail | 2013 |
| Brattensborg Holding AS | Real estate | 2017 |
| Brekkelia AS | Real estate | 2010 |
| Brerus Holding AS | | 2018 |
| Bright Smile AS | Wholesale & retail | 2020 |
| Brinchen & Mykland AS | Construction | 2023 |
| Britt Og Jans Kompass Ans | Health & social care | 1998 |
| Brorer AS | Professional & scientific | 2023 |
| Brudeli Green Mobility AS | Professional & scientific | 2019 |
| Brudeli Tech Holding AS | Professional & scientific | 2001 |
| Bruhjørnet Eiendom AS | Real estate | 1997 |
| Bråten Bilco AS | Other services | 1982 |
| Bråten Brønn Og Energiboring AS | Construction | 2020 |
| Bræin Holding AS | | 2021 |
| Brødrene Amundsen AS | Real estate | 2000 |
| Brødrene Katrud AS | Construction | 1994 |
| BT Recycling AS | Construction | 2014 |
| Buskerud Bil Demontering AS | Wholesale & retail | 2018 |
| Buskerud Fyr & Flamme AS | Wholesale & retail | 1994 |
| Buskerud Gjenvinning AS | Construction | 2001 |
| Buskerud Inneklima AS | Construction | 2026 |
| Buskerud Kulde AS | Construction | 2000 |
| Buskerud Ventilasjonsrens AS | Administrative & support | 2025 |
| Buskerud-Vestfold Kjøleservice AS | Construction | 2026 |
| Bygg-Samordning AS | Construction | 2000 |
| Byggfokus AS | Construction | 2011 |
| Byggmester Svein Bakke AS | Real estate | 1997 |
| Byggmuskler.No AS | Arts & recreation | 2022 |
| Byggtema AS | Real estate | 2005 |
| Bykvartalet AS | Real estate | 2022 |
| BZH Holding AS | | 2025 |
| Bån Eiendom AS | Real estate | 2019 |
| Bån Holding AS | Real estate | 2019 |
| Bøndenes Hus Hokksund AS | Real estate | 2013 |
| Cad Partner AS | Professional & scientific | 2003 |
| Caravan Supply AS | Wholesale & retail | 2010 |
| CB Service & Installation AS | Construction | 2016 |
| CBJ AS | Construction | 2005 |
| CBJ Investment AS | | 2024 |
| Central Auto AS | Other services | 2024 |
| Central Auto Avd Antirust AS | Other services | 2020 |
| Central Auto Eiendom AS | Real estate | 2025 |
| Central Auto Holding AS | Other services | 2024 |
| Chon Ji Taekwondo Academy AS | Education | 2013 |
| Christian Iv's Vei 31 AS | Real estate | 2017 |
| Christiansen Ole Petter AS | Education | 1977 |
| Claras AS | Wholesale & retail | 2018 |
| Comteq AS | Wholesale & retail | 2023 |
| Cortilina AS | | 2023 |
| Cover Group AS | Construction | 2024 |
| Cross Eiendom AS | Real estate | 2022 |
| Curium AS | Financial services | 2005 |
| Cyze AS | Information & communication | 2024 |
| D3I Invest AS | Real estate | 2012 |
| Dahler Holding AS | | 2020 |
| Dahlmann Byggteknikk AS | Construction | 2025 |
| Dammen Eiendom AS | Real estate | 2007 |
| Damvegen 2 Eiendom AS | Real estate | 2010 |
| Darbu Boligprosjekt AS | Real estate | 2012 |
| Darbu Va-Anlegg AS | Water & waste | 2017 |
| DB Håndverker AS | Construction | 2024 |
| DC Networks AS | Construction | 2012 |
| Dcml AS | | 2024 |
| Delaware Eiendom AS | Real estate | 2024 |
| Detailers Club Norway AS | Information & communication | 2015 |
| Din Fabrikk AS | Professional & scientific | 2016 |
| Din Frisør TLS AS | Other services | 2014 |
| Ditt Hagemiljø AS | Wholesale & retail | 2017 |
| Dosp AS | Manufacturing | 2025 |
| Dosp Holding AS | | 2025 |
| Dosp Vestby AS | Real estate | 2025 |