| Bankkvartalet AS | Real estate | 2021 |
| Bankplassen 1A AS | Real estate | 2005 |
| Bankplassen Holding AS | Real estate | 2024 |
| Bankplassen Oslo Eiendom AS | Real estate | 2000 |
| Bankrupt AS | Professional & scientific | 2020 |
| Banks Street AS | Financial services | 2015 |
| Bankshot Holding AS | | 2026 |
| Bankshot Norway AS | Wholesale & retail | 2022 |
| Banktech AS | Information & communication | 2020 |
| Bankveien 10 Eiendomsselskap AS | Real estate | 2005 |
| Bankveien 10 Tomteselskap AS | Real estate | 2005 |
| Bankveien 11 & 14 AS | Real estate | 2008 |
| Bannatyne AS | Real estate | 2006 |
| Banner Import AS | Wholesale & retail | 2014 |
| Banny's House Da | Hospitality | 2010 |
| Bano Holdings AS | | 2023 |
| Banor Holding AS | Transport & logistics | 2021 |
| Banor Transport AS | Transport & logistics | 2019 |
| Banoun AS | | 2023 |
| Banqr AS | Professional & scientific | 2018 |
| Banqsoft AS | Information & communication | 1994 |
| Banquo AS | Professional & scientific | 2016 |
| Bansho AS | Information & communication | 2019 |
| Bant AS | Professional & scientific | 2023 |
| Bantam Digital AS | Professional & scientific | 2019 |
| Bantar Holding AS | Wholesale & retail | 2022 |
| Banyan AS | | 2021 |
| Banzi AS | Real estate | 2003 |
| Baol Eiendom AS | Real estate | 2018 |
| Baoly AS | Information & communication | 2026 |
| Baos Holding AS | Manufacturing | 2025 |
| Bap Capital AS | | 2025 |
| Bapro Solution AS | Professional & scientific | 2022 |
| Bar 2 AS | | 2005 |
| Bar 2028 AS | Hospitality | 2025 |
| Bar Alal AS | Hospitality | 2025 |
| Bar and Beef AS | Hospitality | 2023 |
| Bar and Beyond AS | Hospitality | 2022 |
| Bar Bakke AS | | 2025 |
| Bar Bakke Invest AS | | 2020 |
| Bar Bakke Landskapsarkitekter AS | Professional & scientific | 2006 |
| Bar Bardot AS | Hospitality | 2016 |
| Bar Og Pizzeria Da Paulo Da | Hospitality | 2004 |
| Bar Polar AS | Hospitality | 2014 |
| Bar Sushi Tjuvholmen AS | Hospitality | 2011 |
| Bar Tjuvholmen AS | Hospitality | 2010 |
| Bar Vulkan AS | Hospitality | 2010 |
| Bar-Nathan AS | Health & social care | 2026 |
| Bara AS | Financial services | 2015 |
| Barabas Holding AS | Real estate | 2017 |
| Baracoa Studios AS | Information & communication | 2025 |
| Baraka Holding AS | | 2025 |
| Baraka Invest AS | Wholesale & retail | 2019 |
| Barakagruppen AS | | 2025 |
| Barakat Halal-Kjøtt AS | Wholesale & retail | 2021 |
| Barakuda Holding AS | | 2020 |
| Baransu AS | Health & social care | 2013 |
| Barbarossa Eiendom 2 AS | Real estate | 2013 |
| Barbarossa Eiendom AS | Real estate | 2016 |
| Barber Holding AS | | 2024 |
| Barber&Klipp AS | Other services | 2015 |
| Barberboden AS | Other services | 2026 |
| Barberloungenorway AS | Other services | 2023 |
| Barbershop AS | Wholesale & retail | 2024 |
| Barbershop Vo AS | Other services | 2025 |
| Barberspesialisten AS | Other services | 2025 |
| Barbo Consulting AS | Professional & scientific | 2014 |
| Barbosa Film AS | Information & communication | 2016 |
| Barbros Fotterapi AS | Health & social care | 2020 |
| Barbu Brygge Utleiebygg AS | Real estate | 2013 |
| Barbubukta Eiendomsinvest AS | Real estate | 2017 |
| Barby Gray AS | Wholesale & retail | 2024 |
| Barca Finans AS | | 2016 |
| Barcho AS | Wholesale & retail | 2008 |
| Barcia AS | Professional & scientific | 2025 |
| Barcken Bygg AS | Construction | 2015 |
| Barcode 104 AS | Real estate | 2021 |
| Barcode 113 AS | Real estate | 2021 |
| Barcode 115-125 Holding AS | Real estate | 2008 |
| Barcode 116 AS | Real estate | 2021 |
| Barcode 122 AS | Real estate | 2021 |
| Barcode 124 AS | Real estate | 2021 |
| Barcode 132 AS | Real estate | 2021 |
| Barcode 134 AS | Real estate | 2011 |
| Barcode 135 AS | Real estate | 2021 |
| Barcode Barber Shop AS | Other services | 2024 |
| Barcode Basement AS | Real estate | 2005 |
| Barcode Basement Drift AS | Real estate | 2019 |
| Barcode Butikkdrift AS | Wholesale & retail | 2017 |
| Barcode Hjemmel 1 AS | Real estate | 2005 |
| Barcode Intelligence AS | Professional & scientific | 2013 |
| Barcode Kjøling AS | Energy | 2011 |
| Barcode Portfolio AS | Real estate | 2017 |
| Barcode Pubdrift AS | Hospitality | 2016 |
| Barcode Street Food AS | Hospitality | 2021 |
| Barcontrol Systems AS | Information & communication | 2011 |
| Bard Holding AS | Real estate | 2014 |
| Bardo Computing AS | Information & communication | 2018 |
| Bardoff Invest AS | Real estate | 2007 |
| Bardrift Holding AS | | 2026 |