| Ballkeeper AS | Wholesale & retail | 2025 |
| Baltic Exchange Norge AS | Wholesale & retail | 1989 |
| Balut AS | Professional & scientific | 2011 |
| Bambus Familieklinikk AS | Health & social care | 2015 |
| Banksia AS | | 2024 |
| Banor Utvikling AS | Construction | 2021 |
| Bar Humor Da | Professional & scientific | 2000 |
| Barcelona Guy Names Da | Professional & scientific | 2000 |
| Barnas Hule Da | Wholesale & retail | 2004 |
| Barstad-Ølnes Invest AS | Financial services | 2016 |
| Bbjerknes Holding AS | | 2021 |
| Bblykke AS | | 2023 |
| BCH AS | Real estate | 2021 |
| Beabeth AS | | 2024 |
| Beauty Unlimited AS | Other services | 2020 |
| Beautyno Da | Professional & scientific | 1999 |
| Bed and Breakfast - Konsertarrangementer Da | Professional & scientific | 2000 |
| Beis & Maling & Lakk Da | Professional & scientific | 2000 |
| Bekk Elektro AS | Construction | 2026 |
| Beolis AS | | 2018 |
| Beren AS | Real estate | 2013 |
| Berge Molinari Invest AS | Financial services | 2016 |
| Bergenstorgetno Da | Information & communication | 2000 |
| Berghaugen Helsesenter Da | Professional & scientific | 2000 |
| Bergsaker Invest AS | | 2025 |
| Bergtor Invest AS | Real estate | 2006 |
| Bid Og Konkurs Da | Professional & scientific | 2000 |
| Bie Arkitektur AS | Professional & scientific | 2026 |
| Big Bear Consult AS | Information & communication | 2020 |
| Biht Holding AS | | 2021 |
| Bil Jakt Og Kvinner Da | Professional & scientific | 2000 |
| Bingo Fuel AS | | 2021 |
| Bio-Trio Whiskey Da | Professional & scientific | 2000 |
| Biofedora AS | Wholesale & retail | 2013 |
| Biofedora Nuf | Wholesale & retail | 2016 |
| Biosmartec AS | | 2010 |
| Bislet Bikini Bryllup Da | Information & communication | 2000 |
| Bislet T-Shirt Og Utstyrsmagasin Da | Professional & scientific | 2000 |
| Bislet Trim Og Tolk Da | Professional & scientific | 2000 |
| Bislett Urter Og Parafin Da | Professional & scientific | 2000 |
| Biørnstad Holding AS | | 2024 |
| Bjørn Authén AS | Professional & scientific | 2019 |
| Bjørn Invest AS | | 2021 |
| Blekk & Blikk Band Da | Professional & scientific | 2000 |
| Blond Og Sprit Da | Professional & scientific | 2000 |
| Blue Duck AS | Information & communication | 2020 |
| Blue Lemon AS | | 2020 |
| Blueberry Photography AS | Education | 2019 |
| Bluesky AS | Manufacturing | 2023 |
| Blunk Agency AS | Wholesale & retail | 2021 |
| Blåsen AS | Real estate | 2016 |
| Boa Takst AS | Professional & scientific | 2016 |
| Boddern AS | Financial services | 2017 |
| Bodyno Da | Wholesale & retail | 1999 |
| Bok Magi Da | Information & communication | 2000 |
| Bokami AS | Information & communication | 2020 |
| Bolina AS | Wholesale & retail | 1986 |
| Bolverket Holding AS | | 2024 |
| Bomiljø AS | Real estate | 2017 |
| Bomskudd Topp 10 Da | Professional & scientific | 2000 |
| Bonka Commercial Management AS | Professional & scientific | 2025 |
| Bonordic AS | Wholesale & retail | 2012 |
| Bonson AS | Real estate | 2009 |
| Borg & Bigum Norge AS | Wholesale & retail | 1951 |
| Borka Consulting AS | Professional & scientific | 2009 |
| Boulder Holding AS | Wholesale & retail | 2005 |
| Boxo AS | Wholesale & retail | 2021 |
| Boxton Management AS | Professional & scientific | 2016 |
| Boy Cinza Da | Professional & scientific | 2000 |
| BPS Bekkestua Parkettsliperi AS | Construction | 2012 |
| Brandy Mobler Da | Professional & scientific | 2000 |
| Brawon Bygg AS | Construction | 2020 |
| Breaking Formation AS | Information & communication | 2026 |
| Bremer Consulting AS | Professional & scientific | 2019 |
| Bromarf Holding AS | | 2022 |
| Brus Holding AS | | 2022 |
| Bryngel IT AS | Information & communication | 2018 |
| Brødrene Kolstad AS | Wholesale & retail | 1933 |
| Brødrene Kolstad Installasjon AS | Construction | 1998 |
| Bursdagno Da | Professional & scientific | 2000 |
| Busi Holding AS | Wholesale & retail | 2024 |
| Businessno Da | Information & communication | 1999 |
| By the Pond Da | Wholesale & retail | 2007 |
| Bygg Bulinski AS | Construction | 2022 |
| Bygge-Bo AS | Real estate | 1989 |
| Byggreform AS | Construction | 2013 |
| Bærum Bil & Eiendom AS | Other services | 2018 |
| Bærum Bunad Og Makeup Da | Information & communication | 2000 |
| Bærum Rørservice AS | Construction | 2007 |
| Bærums Verk Rørleggerbedrift AS | Construction | 2010 |
| C.T.Kvaalen Holding AS | | 2025 |
| Ca Auto Finance Norge AS | Wholesale & retail | 2015 |
| Cab & Pollen Agency Da | Professional & scientific | 2019 |
| Cacem Holding AS | Financial services | 1987 |
| Caelum AS | Real estate | 2006 |
| Cafe Colombiano Scandinavia AS | Wholesale & retail | 2022 |
| Cahoma Invest AS | | 2024 |
| Calle Andersen Murmester AS | Construction | 2016 |
| Cama Reform AS | Wholesale & retail | 2025 |
| Camilla Abry AS | Professional & scientific | 2022 |