| Arne Olav Lund A/S | Construction | 1965 |
| B Bolig AS | Real estate | 2022 |
| B Næring AS | Real estate | 2022 |
| B&K Produksjon Og Utleie AS | Administrative & support | 2016 |
| B. Børresen Eiendom AS | Construction | 2004 |
| B.Boligtakst AS | Real estate | 2023 |
| B.K. Piene AS | Financial services | 2005 |
| B1 Næringspark AS | Real estate | 2022 |
| B4 Næringspark AS | Real estate | 2022 |
| Baber 399 Holding AS | | 2023 |
| Bach Johansen Håndverk AS | Construction | 2013 |
| Bach Skuggedal AS | Administrative & support | 2023 |
| Bad Flis & Restaurering Da | Construction | 2007 |
| Bakersmia Cafe AS | Hospitality | 2024 |
| Bakkebygrenda Barnehage SA | Education | 1988 |
| Balozi AS | Real estate | 2007 |
| Baltic Deal AS | Administrative & support | 2017 |
| Bamyr Holding AS | | 2025 |
| Barcompagniet AS | Information & communication | 2016 |
| Barepia AS | Professional & scientific | 2023 |
| Barkåker Eiendom 2 AS | Real estate | 2019 |
| Bas Kunst AS | Wholesale & retail | 1997 |
| Bassengutstyr AS | Wholesale & retail | 2015 |
| Bassengutstyr Pettersen Holding AS | Real estate | 2015 |
| Bastant Eiendom AS | Real estate | 1987 |
| Batteri.No AS | Wholesale & retail | 2004 |
| Bawa AS | Real estate | 2004 |
| Baxt AS | Wholesale & retail | 1995 |
| Baxt Gruppen AS | Wholesale & retail | 2017 |
| BBG 5 Notodden AS | Real estate | 2010 |
| BBV AS | Other services | 2023 |
| Beauty Lab AS | Other services | 2022 |
| Becc AS | | 2024 |
| Bedehuset Mat AS | Hospitality | 2015 |
| Bedko AS | Information & communication | 2011 |
| Bedre Flyt AS | Professional & scientific | 2021 |
| Bedriftshelsen AS | Health & social care | 1987 |
| Bekkelund & Knutsen AS | Manufacturing | 2003 |
| Bella Rosa Jamshid Og Ezat Ans | Hospitality | 2001 |
| Belman Production | Wholesale & retail | 2005 |
| Bengtssons Maskin AB Filial Nuf | Wholesale & retail | 2019 |
| Benjamin Tvedten AS | | 2025 |
| Benji Holding AS | Other services | 2021 |
| Bentepettersen AS | Wholesale & retail | 2024 |
| Berge Godt & Grønt AS | Agriculture & fishing | 2001 |
| Bergeløkka AS | Real estate | 2008 |
| Bergene Holm Eiendom AS | Real estate | 2016 |
| Berglem AS | | 2020 |
| Bergsala Aktiebolag Nuf | Wholesale & retail | 2026 |
| Bergsala AS | Wholesale & retail | 1946 |
| Bergslia AS | Professional & scientific | 2022 |
| Bernhardsen Hage Og Maskin Service AS | Wholesale & retail | 2020 |
| Bernina Sysenter Da | Wholesale & retail | 1992 |
| Berserker AS | Wholesale & retail | 2019 |
| Bertas Eiendom AS | Hospitality | 2001 |
| Berthelsen Industrisenter AS | Wholesale & retail | 1991 |
| Beslag Giganten AS | Wholesale & retail | 2024 |
| Best Bilpleie 1 AS | Other services | 2025 |
| Best Choice AS | Real estate | 2015 |
| Best Choice Eiendom AS | Real estate | 2022 |
| Best Teleprodukter AS | Wholesale & retail | 1995 |
| Beste Bolig AS | Real estate | 2022 |
| Bestsource AS | Wholesale & retail | 2021 |
| Beto Bygg & Eiendom AS | Real estate | 2006 |
| Beto Regnskap AS | Professional & scientific | 2022 |
| Betthov Holding AS | | 2025 |
| Bevola Norge AS | Wholesale & retail | 1997 |
| BFB Eiendom AS | Real estate | 2020 |
| Bga Holding AS | Professional & scientific | 2007 |
| Bga Prosjekt AS | Professional & scientific | 2006 |
| Bibliotek-Systemer A/S | Information & communication | 1988 |
| Bigsee AS | Education | 2022 |
| Bikuben Eiendom AS | Real estate | 1968 |
| Bil Rep AS | Other services | 2005 |
| Bilberging 24 AS | Transport & logistics | 2017 |
| Bildebloggen AS | Transport & logistics | 2024 |
| Billigabo.No AS | Information & communication | 2023 |
| Billy Markiser AS | Wholesale & retail | 2024 |
| Bilmeta AS | Wholesale & retail | 2019 |
| Bilpleiesenteret Larvik AS | Other services | 2014 |
| Bilrutene Østre Halsen Rekkevik Ans | Real estate | 1971 |
| Biozin Holding AS | | 2017 |
| Bisjord Fus Barnehage AS | Education | 2018 |
| Bistro Istanbul AS | Hospitality | 2024 |
| Bit by Bit IT AS | Information & communication | 2025 |
| Bjerke Samdrift Ans | Agriculture & fishing | 2011 |
| Bjørnestad Foundation AS | Real estate | 2018 |
| Bjørnø Maskin AS | Construction | 2001 |
| BKC Industriteam AS | Real estate | 2006 |
| Blafro Service AS | Professional & scientific | 2007 |
| Blafro Tools AS | Professional & scientific | 2002 |
| Blefjell Bygg AS | Construction | 2022 |
| Blefjell Holding AS | Construction | 2020 |
| Blefjell Hytteeiendom AS | Real estate | 2022 |
| Blefjell Hytteselskap AS | Construction | 2018 |
| Blefjell Hytteutleie AS | Real estate | 2019 |
| Blefjell Hytteutvikling AS | Real estate | 2019 |
| Blefjelltunet AS | Real estate | 2019 |
| Bleivik Hse & Project Management AS | Professional & scientific | 2009 |
| BLG Invest AS | Real estate | 2016 |