| Betong & Asfalt-Tjenester AS | Construction | 2020 |
| Bevegdeg AS | Education | 2023 |
| Beveo Kiropraktikk Og Fysioterapi Da | Health & social care | 2021 |
| Beø AS | Real estate | 2024 |
| BF Eiendom Invest AS | Real estate | 2019 |
| BGF Forvaltning AS | | 2026 |
| Bgs-Bygg AS | Construction | 2016 |
| BGT Holding AS | Wholesale & retail | 2015 |
| BH Bil AS | Wholesale & retail | 2022 |
| Bi-B AS | Real estate | 2005 |
| Bi-M AS | Professional & scientific | 2007 |
| Biamp Europe Nuf | Professional & scientific | 2017 |
| Big Leap Consult & Invest AS | Professional & scientific | 2013 |
| Bil Centeret AS | Wholesale & retail | 2021 |
| Bilbo A/L | | 1959 |
| Bilbrødrene AS | Wholesale & retail | 2020 |
| Bilfix Da | Other services | 2003 |
| Bilfreak AS | Wholesale & retail | 2023 |
| BILINNREDER1 AS | Other services | 2024 |
| Bilinnredern AS | Other services | 2008 |
| Bilkjøp Støhlmacher & Co Ans | Wholesale & retail | 1989 |
| Bilmesser.No AS | Administrative & support | 2026 |
| Bilskadesenteret Telemark AS | Other services | 2004 |
| Bilskadespesialisten AS | Other services | 2004 |
| Bilteam AS | Other services | 2019 |
| Bilvask Invest AS | Professional & scientific | 2021 |
| Bio Eiendom AS | Real estate | 2006 |
| Biome AS | Professional & scientific | 2020 |
| Bionor Laboratories AS | Professional & scientific | 1996 |
| Birger Holding AS | Financial services | 2005 |
| Birgit Holding AS | | 2019 |
| Birk Bygg AS | Construction | 2006 |
| Birk Eiendom AS | Real estate | 2011 |
| Bits & Hills AS | Information & communication | 2022 |
| Bivrost Eiendom AS | Real estate | 2022 |
| Bivrost Holding AS | Real estate | 2019 |
| Bix Eiendom Holding AS | | 2020 |
| Bjemcach AS | | 2021 |
| Bjerkeley Holding AS | | 2024 |
| Bjerkelund Express Service AS | Transport & logistics | 2012 |
| Bjerva Eiendom AS | Real estate | 1998 |
| Bjerva Holding AS | Real estate | 2005 |
| Bjerva Products AS | Professional & scientific | 2019 |
| Bjonvik AS | Wholesale & retail | 2013 |
| Bjorstaddalen Næring AS | Transport & logistics | 2014 |
| Bjåen Egeland Invest AS | Construction | 2012 |
| Bjåland Eiendom AS | Real estate | 2024 |
| Bjørbekk Eiendom AS | Real estate | 1983 |
| Bjørbekk Elektro AS | Construction | 2007 |
| Bjørbekk Holding AS | Real estate | 2006 |
| Bjørge Karosseri AS | Other services | 1988 |
| Bjørkelund Utvikling AS | Real estate | 2020 |
| Bjørkelund Vest AS | | 2025 |
| Bjørn Danielsen Holding AS | Construction | 2012 |
| Bjørn Furuheim AS | Construction | 2006 |
| Bjørn Håkonsen AS | | 1988 |
| Bjørn Håkonsen Regnskap AS | Professional & scientific | 2024 |
| Bjørn Rørvik Invest AS | | 2024 |
| Bjørnback AS | Construction | 2008 |
| Bjørndalen Pukkverk AS | Mining & quarrying | 2003 |
| Bjørnegården 1 AS | Real estate | 2021 |
| Bjørnfeld Bygg AS | Construction | 2020 |
| Bjørnfeld Invest AS | Real estate | 2020 |
| Bjørns AS | Professional & scientific | 2016 |
| Bjørnstjerne Bjørnsons Veg 45 AS | Real estate | 2024 |
| Bjørntvedt Eiendom AS | Real estate | 2023 |
| Bjørntvedt Invest AS | Real estate | 2021 |
| Bjørntvedtvegen 150 Syd AS | Real estate | 2013 |
| Bjørntvedtvegen 156 AS | Real estate | 2020 |
| BL Holding AS | Financial services | 2015 |
| Black Cloud AS | Construction | 2014 |
| Blekebakkvegen 1 AS | Real estate | 2017 |
| Blekebakkvegen 3 AS | Real estate | 2007 |
| Blekebakkvegen 5 Eiendom AS | Real estate | 2014 |
| Blekebakkvegen 5 Gjærhuset AS | Real estate | 2016 |
| Blikkenslager Frank Valhovd Andersen AS | Construction | 2011 |
| Blikkenslager Kvelland AS | Construction | 2013 |
| Blikkenslager Lauritzen AS | Construction | 2002 |
| Blikkenslager Morten Valhovd Andersen AS | Construction | 2014 |
| Blixen Tours Norway AS | Administrative & support | 2014 |
| Blomsterbudet Da | Transport & logistics | 1995 |
| Blomsterdrift Gallefos AS | Wholesale & retail | 2010 |
| Blomsterslottet AS | Wholesale & retail | 2025 |
| Bloom Collective AS | Professional & scientific | 2025 |
| Blue Jeans AS | Wholesale & retail | 1989 |
| Bluegrass AS | Financial services | 2014 |
| Bluesky Mondan AS | Hospitality | 2025 |
| Bluesteel Holding AS | Information & communication | 2017 |
| Blå Kors Klinikk Skien AS | Health & social care | 1978 |
| Blå Skyer Eiendom AS | Real estate | 2015 |
| BM Lindefjeld AS | Construction | 2020 |
| BMG Holding AS | | 2020 |
| BN Familierådgivning AS | Health & social care | 2013 |
| Bna Holding AS | | 2005 |
| Boat Lift Nuf | Manufacturing | 2023 |
| Bobbleheads Norge AS | Wholesale & retail | 2016 |
| Bolig Design AS | Professional & scientific | 2024 |
| Boligbyggelagenes Boservice AS | Administrative & support | 2001 |
| Boligentreprenøren AS | Construction | 2020 |
| Boligentreprenøren Holding AS | Administrative & support | 2020 |