| Boligbygg AS | Professional & scientific | 1998 |
| Boliglyst Asker Og Drammen AS | Real estate | 2025 |
| Bom AS | | 2024 |
| Bondi VVS AS | Construction | 2016 |
| Bonkers AS | Information & communication | 2024 |
| Bonsy AS | Information & communication | 2018 |
| Boostenergy AS | Professional & scientific | 2025 |
| Boresight and Alignment Solutions AS | Professional & scientific | 2021 |
| Borgen Elektriske AS | Construction | 2012 |
| Borgeskogen Energi AS | Energy | 2024 |
| Borgeskogen Nord AS | Real estate | 2018 |
| Borgeskogen Øst Tomt 11 AS | Real estate | 2022 |
| Borgeskogen Øst Tomt 12 AS | Real estate | 2022 |
| Borgeskogen Øst Tomt 15 AS | Real estate | 2022 |
| Borgeskogen Øst Tomt 16 AS | Real estate | 2022 |
| Borgeskogen Øst Tomt 17 AS | Real estate | 2022 |
| Borgeskogen Øst Tomt 18 AS | Real estate | 2022 |
| Borgeskogen Øst Tomt 19 AS | Real estate | 2022 |
| Borgeskogsvingen 15 AS | Real estate | 2019 |
| Bortimotalterfett AS | Professional & scientific | 2024 |
| Bos Invest AS | Real estate | 2018 |
| Boxs Arkitektstudio AS | Professional & scientific | 2022 |
| BPS AS | Professional & scientific | 2014 |
| BR Malerservice AS | Construction | 2024 |
| Braathen & Finvold Da | Professional & scientific | 2009 |
| Braathen Truckservice AS | Manufacturing | 1989 |
| Bragernes Parkering AS | Real estate | 2014 |
| Bragernes Torg 1 AS | Real estate | 2006 |
| Bragernes Torg 10 AS | Real estate | 2017 |
| Bragernes Torg 12 AS | Real estate | 2019 |
| Bragernes Torg 8 AS | Real estate | 1987 |
| Brahaug AS | Professional & scientific | 2017 |
| Brakar Holding AS | | 2020 |
| Branten Utvikling AS | Professional & scientific | 2022 |
| Braskeståva Invest AS | Information & communication | 2005 |
| Bratlie Eiendom AS | Real estate | 2025 |
| Brattbakk Bilit Holding AS | | 2022 |
| Bravura AS | Mining & quarrying | 2013 |
| Breez AS | Wholesale & retail | 2025 |
| Breflow AS | Information & communication | 2026 |
| Brennesland AS | Professional & scientific | 2021 |
| Briberg Invest AS | | 2022 |
| Bright & Early AS | Professional & scientific | 1990 |
| Bright People Rekruttering & Bemanning AS | Administrative & support | 2012 |
| Brightbid Norge AS | Information & communication | 2021 |
| Brodin Holdings AS | | 2023 |
| Brodwall Berge Holding AS | Health & social care | 2024 |
| Brooks Sports AB | Professional & scientific | 2024 |
| Brsk Invest AS | Information & communication | 2022 |
| Brutus Invest AS | Real estate | 1994 |
| Bsure AS | Information & communication | 2022 |
| BSV Investment Group AS | | 2017 |
| Buggeberget AS | Wholesale & retail | 2021 |
| Buildex AS | Information & communication | 2026 |
| Building Bits AS | Information & communication | 2026 |
| Bulken Invest AS | Financial services | 2006 |
| Bull Sarhan AS | | 2021 |
| Burgerpelle AS | Hospitality | 2021 |
| Bus Invest 1 AS | Financial services | 2015 |
| Buskerud Elektro AS | Construction | 2017 |
| Buskerudveien Bolig AS | Real estate | 2016 |
| Buskerudveien Bolig II AS | Real estate | 2018 |
| Buskerudveien Bolig III AS | Real estate | 2018 |
| Buskerudveien Bolig IV AS | Real estate | 2021 |
| Buskerudveien Bolig V AS | Real estate | 2022 |
| Buskerudveien Eiendom AS | Real estate | 2016 |
| Butikkdrift Larsen AS | Wholesale & retail | 2019 |
| Butikkdrift Ramaki AS | Wholesale & retail | 2026 |
| Buzz Aldrin AS | Real estate | 2006 |
| BVN9 AS | Real estate | 2022 |
| BWT Birger Christensen AS | Construction | 1962 |
| By:Songs AS | Arts & recreation | 2014 |
| Bygdøy Allè 59 AS | Real estate | 1980 |
| Bygg Grant AS | Construction | 2024 |
| Bygg Og Tømrerfirma Hoff Dybvik AS | Construction | 2010 |
| Bygg Vision Norge AS | Construction | 2015 |
| Bygg-Alex AS | Construction | 1998 |
| Byggmester Tor Tveit AS | Construction | 2005 |
| Byggmestern Asker AS | Construction | 2010 |
| Båstadmyra Barnehage SA | Education | 1994 |
| Bæksøm AS | Wholesale & retail | 2015 |
| Bøckmann AS | | 2024 |
| Børresens Byrå AS | | 2024 |
| Caco Eiendom AS | Real estate | 2018 |
| Caman AS | Professional & scientific | 2025 |
| Camana AS | Real estate | 1993 |
| Cambi ASA | Professional & scientific | 1996 |
| Cambi Group AS | Professional & scientific | 2006 |
| Cambi Solutions AS | Professional & scientific | 1986 |
| Cambi Technology AS | Professional & scientific | 2012 |
| Camreach AS | Information & communication | 2025 |
| Camros AS | Professional & scientific | 2015 |
| Canaro AS | Professional & scientific | 2026 |
| Caoz AS | Wholesale & retail | 2003 |
| Carbon Holding AS | | 2022 |
| Carbon Twelve AS | Professional & scientific | 2021 |
| Cardio Nordic AS | Wholesale & retail | 2019 |
| Caresafe AS | Manufacturing | 2023 |
| Carm-E Holdings AS | | 2021 |
| Carpet on Net AS | Wholesale & retail | 2005 |