| Boligforum AS | Construction | 1995 |
| Bolton Byggsenter AS | Wholesale & retail | 2017 |
| Bolyhus AS | Professional & scientific | 2017 |
| Bonsai AS | Wholesale & retail | 2024 |
| Book Apartments AS | Hospitality | 2018 |
| Borgar Kittilsen AS | Real estate | 2011 |
| Borgar Kittilsen Eiendom AS | Real estate | 2010 |
| Borgar Kittilsen Holding AS | Other services | 2005 |
| Borgar Kittilsen Verksted AS | Other services | 2004 |
| Borgegrenda Utvikling AS | Real estate | 2019 |
| Borgen Holding AS | Other services | 2018 |
| Borgen-Eiendom AS | Real estate | 2020 |
| Borgersen Eiendom AS | Real estate | 1985 |
| Borgertun Eiendomsutvikling AS | Real estate | 2016 |
| Borgeskogen Sør AS | Real estate | 2020 |
| Borgestad Bolig AS | Real estate | 2026 |
| Borgestad Bygg AS | Construction | 2014 |
| Borgestad Eiendomsutvikling AS | Real estate | 2014 |
| Borgestad Gård AS | Agriculture & fishing | 2017 |
| Borgestadgrillen AS | Hospitality | 2017 |
| Borgesterner AS | | 2019 |
| Borgeåsen Blomster AS | Wholesale & retail | 2006 |
| Borgeåsen Fysikalske Institutt Eiendom AS | Real estate | 2017 |
| Borgeåsen Fysikalske Institutt Holding AS | Real estate | 2017 |
| Borgeåsen II AS | Real estate | 2009 |
| Borgeåsen Legesenter Da | Health & social care | 2002 |
| Borgum Eiendom AS | Real estate | 2017 |
| Borkman AS | Administrative & support | 2022 |
| Bot Eiendom AS | Real estate | 2021 |
| Botten Invest AS | | 2019 |
| Bovieran Falkum AS | Real estate | 2021 |
| BR Utvikling AS | Financial services | 2018 |
| BR. Skilbred Landbruk AS | Agriculture & fishing | 2004 |
| Bra Helse AS | Health & social care | 2007 |
| Bra Taksering AS | Real estate | 2025 |
| Brann Og Førstehjelpskurs AS | Education | 2024 |
| Branningeniøren AS | Professional & scientific | 2006 |
| Brannteknikk Grenland AS | Professional & scientific | 2002 |
| Bratsberg Amt Holding AS | Financial services | 2005 |
| Bratsberg Amt Invest AS | Real estate | 2006 |
| Bratsberg Autosenter AS | Wholesale & retail | 2003 |
| Bratsberg Brygge Invest AS | Manufacturing | 2005 |
| Bratsberg Finans AS | Real estate | 2012 |
| Bratsberg Landmandsforretning AS | Real estate | 1988 |
| Bratsberg Len Holding AS | Financial services | 2016 |
| Bratsberg Maskin AS | Construction | 2021 |
| Bratsberg- Rønningen Gård Da | Agriculture & fishing | 2018 |
| Bratsbergkleiva Eiendom AS | Real estate | 2016 |
| Brauti Holding AS | Health & social care | 2014 |
| Bravebu AS | Hospitality | 2022 |
| Breckenridge AS | | 2021 |
| Brede Og Bjørns Elektroservice AS | Other services | 1994 |
| Breitind Forlag AS | Information & communication | 2023 |
| Brekke Barnehage SA | Education | 1994 |
| Brekke Eiendom AS | Real estate | 1993 |
| Brenne Og Algrøy Interiør & Boligstyling AS | Professional & scientific | 2018 |
| Brikkenerd AS | Wholesale & retail | 2025 |
| Brodahl Invest AS | | 2026 |
| Brog Stine Og Nina Ans | Agriculture & fishing | 1995 |
| Bromely Holding AS | Financial services | 2016 |
| Bromsl AS | | 2026 |
| Brua Bilverksted AS | Other services | 2013 |
| Brubergåsen AS | Real estate | 2025 |
| Bruktbil 24-7 AS | Wholesale & retail | 2024 |
| Bruktbilxpress AS | Wholesale & retail | 2022 |
| Brynhildsen Fjellsprengning AS | Construction | 2005 |
| Brystlomma AS | Wholesale & retail | 2024 |
| Brødr Berg Eiendom AS | Wholesale & retail | 2005 |
| Brødr Berg Stenindustri AS | Wholesale & retail | 1994 |
| Brødrene Eie Glass Og Tre AS | Construction | 1977 |
| Brødrene Henriksen Eiendom AS | Real estate | 2019 |
| Brødrene Henriksen Transport AS | Transport & logistics | 2013 |
| Brødrene Johnsen Elektroservice AS | Construction | 2004 |
| Brødrene Reiersen Flis Og Mur AS | Construction | 2011 |
| Brødrene Thorsen AS | Construction | 1993 |
| BS Drift AS | Health & social care | 2022 |
| BS Solutions AS | Professional & scientific | 2018 |
| BSP Bygg AS | Construction | 2019 |
| BTJ Invest AS | Wholesale & retail | 2021 |
| BTR Motor AS | Wholesale & retail | 2022 |
| Btsg Media AS | Information & communication | 2017 |
| Bucketlist Holding AS | Transport & logistics | 2017 |
| Buer Eiendom AS | Real estate | 2021 |
| Buer Utemiljø AS | Wholesale & retail | 2010 |
| Buers Boligutleie AS | Real estate | 2024 |
| Buers Grave Transport AS | Construction | 1995 |
| Buers Holding AS | Construction | 2024 |
| Buffalo Grill Ans | Hospitality | 2000 |
| Bugten Sandtak AS | Mining & quarrying | 1997 |
| Buketten AS | Wholesale & retail | 2014 |
| Bumblebee Invest AS | Professional & scientific | 2020 |
| Bunad Hilde AS | Manufacturing | 2016 |
| Bunad Og Bøll Da | Manufacturing | 2023 |
| Bunker Invest AS | | 2024 |
| Business Garden AS | Real estate | 2022 |
| Butikkdrift Mehari Tsegay AS | Wholesale & retail | 2023 |
| Butikkdrift Mehari.T AS | Wholesale & retail | 2026 |
| Butikkdrift Skien AS | Wholesale & retail | 2015 |
| Butikkpartner AS | Professional & scientific | 2008 |
| Buvill Invest AS | Professional & scientific | 2015 |