| Bjarne Holen Utvikling Og Drift AS | Information & communication | 2019 |
| Bjeff Kommunikasjon Da | Arts & recreation | 2021 |
| Bjerkan Holding AS | Real estate | 2020 |
| Bjerkan Stav Advokatfirma AS | Professional & scientific | 2013 |
| Bjerke Hydro AS | Professional & scientific | 2013 |
| Bjorkaas Eiendom AS | Real estate | 2025 |
| Bjornsiv AS | Health & social care | 2021 |
| Bjugntorget AS | Real estate | 2015 |
| Bjølin Holding AS | Financial services | 2011 |
| Bjørgo Holding AS | | 2025 |
| Bjørkhaugen Transport Og Utleie AS | Transport & logistics | 2018 |
| Bjørkhaugvegen 27 AS | Real estate | 1995 |
| Bjørkmyrtunet Utvikling AS | Real estate | 2017 |
| Bjørn a Fossum AS | Real estate | 2010 |
| Bjørn Indergård Invest AS | Construction | 2005 |
| Bjørn Krogstad AS | Real estate | 2008 |
| Bjørn Magnussen AS | Arts & recreation | 2025 |
| Bjørn Rønne Invest AS | Financial services | 2005 |
| Bjørn Smeby AS | | 2021 |
| Bjørn Stallares Gate 5 AS | Real estate | 2018 |
| Bjørnar Oust AS | Administrative & support | 2015 |
| Bjørnar Oust Holding AS | | 2023 |
| Bjørndalen 1-3 AS | Real estate | 2012 |
| Bjørnebo AS | Real estate | 2004 |
| Bjørnebo Holding AS | | 2011 |
| BJØRNEBY5 Holding AS | | 2026 |
| Bjørnen Eiendom AS | Real estate | 2001 |
| Bjørni Invest AS | Real estate | 2001 |
| Bjørnnes AS | Information & communication | 2007 |
| Bjørnstad AS | Real estate | 2004 |
| Bjørnungan Holding AS | | 2019 |
| Bjørset Holding AS | Information & communication | 2021 |
| BK Byggsøk AS | Construction | 2005 |
| BK Eiendom AS | | 2016 |
| BK Horisont Eiendom AS | Real estate | 2025 |
| BK Maskin AS | Construction | 2022 |
| BK Parkering AS | Transport & logistics | 2020 |
| BK Solo AS | | 2019 |
| BK Utleie AS | Real estate | 2020 |
| Bke Maling Og Snekkerservice AS | Construction | 2022 |
| Blaa Kapital AS | Professional & scientific | 2016 |
| Blaahval Eiendom AS | Real estate | 2013 |
| Blaane Film AS | Information & communication | 2018 |
| Blaane Produksjon AS | Information & communication | 2024 |
| Blaasenborg Holding AS | Real estate | 2009 |
| Blaasmo Holding AS | Real estate | 2021 |
| Blaasmo Invest AS | | 2019 |
| Black Monday Holding AS | Financial services | 2016 |
| Black Sea Rental AS | Administrative & support | 2015 |
| Blackjack AS | Construction | 2014 |
| Blackmeno AS | Wholesale & retail | 2024 |
| Blakstad Elektro AS | Construction | 2016 |
| Blanktjern Coaching AS | Professional & scientific | 2022 |
| Blanktjern Holding AS | Professional & scientific | 2014 |
| Blekk & Blod AS | Real estate | 2010 |
| Blekkan Eiendom AS | Real estate | 2015 |
| Blekkhus AS | Real estate | 2023 |
| Blekkunst AS | Arts & recreation | 2019 |
| Blikkenslagerservice AS | Construction | 2014 |
| Blikø Tekstil Og Design AS | Wholesale & retail | 2023 |
| Blims Tech AS | Information & communication | 2016 |
| Blind Høne AS | Financial services | 2024 |
| Blinde Bonde & Babe AS | Wholesale & retail | 2017 |
| Bling Design Studio AS | Other services | 2017 |
| Blinklys Da | Professional & scientific | 2005 |
| Blix Arkitektkontor AS | Professional & scientific | 1998 |
| Blixrudi Holding AS | | 2020 |
| BLK Holding AS | | 2025 |
| Blodstrupmoen Holding AS | Wholesale & retail | 2021 |
| Blokkheim AS | Real estate | 2010 |
| Blokksberg Finans AS | | 2026 |
| Blokksberg Holding AS | | 2025 |
| Bloksberg Frisør AS | Other services | 2012 |
| Blomkvartalet Bolig AS | Real estate | 2020 |
| Blomm Holding AS | | 2020 |
| Blomster I Byhaven AS | Wholesale & retail | 2008 |
| Blomster På Byåsen AS | Wholesale & retail | 2005 |
| Blomsteraaen AS | Wholesale & retail | 2008 |
| Blomstertorget Trondheim AS | Wholesale & retail | 2005 |
| Blomsøy Borgan Da | Professional & scientific | 2001 |
| Blonde Rose Da | Arts & recreation | 2026 |
| Bloodpc AS | Wholesale & retail | 2026 |
| Bloomlet Technologies AS | Information & communication | 2024 |
| Blow AS | Other services | 2005 |
| Blue Iguana AS | Professional & scientific | 2024 |
| Blue Skies Holding AS | | 2024 |
| Bluebird AS | | 2024 |
| Bluecask AS | Information & communication | 2014 |
| Bluecirc AS | Professional & scientific | 2017 |
| Blueprint Holding AS | | 2016 |
| Blueprint Music AS | Information & communication | 2022 |
| Blues for the Red Sun AS | Information & communication | 2015 |
| Bluesette Holding AS | Arts & recreation | 2024 |
| Bluesette Media AS | Arts & recreation | 2012 |
| Bluestreak Innovations AS | Information & communication | 2024 |
| Blueye Robotics AS | Professional & scientific | 2015 |
| Blussuvollsbakken 20 AS | Real estate | 2012 |
| Blusuvold Kapital AS | Professional & scientific | 2016 |
| Blusuvollsbakken Holding AS | Financial services | 2005 |
| Bly Holding AS | | 2026 |