| Asala Holding AS | Wholesale & retail | 2018 |
| Asfaltspesialistene AS | Construction | 2022 |
| Asgeir Holding AS | Real estate | 2020 |
| ASK123 AS | Wholesale & retail | 2020 |
| Asker Og Bærum BS Teknikk AS | Other services | 1995 |
| ASV8 AS | Real estate | 2022 |
| At&T Invest AS | Real estate | 2010 |
| Atal Holding AS | Health & social care | 2023 |
| Atelier Online AS | Wholesale & retail | 2020 |
| Athena Kurs Og Internkontroll AS | Professional & scientific | 2024 |
| Athletic Records AS | Information & communication | 2013 |
| Athletic Sound AS | Information & communication | 1984 |
| Atvendo AS | Professional & scientific | 2022 |
| Audax Invest AS | Wholesale & retail | 2023 |
| Auensen Bygg AS | Construction | 2012 |
| Auensen Maskinentreprenør AS | Construction | 2012 |
| Aurora Borealis Investment Holding AS | Real estate | 2017 |
| Auto C AS | Wholesale & retail | 2021 |
| Auto-Rekvisita AS | Wholesale & retail | 1989 |
| Autohaven AS | Wholesale & retail | 2025 |
| Avante Auto AS | Wholesale & retail | 2026 |
| Ayolaz AS | Hospitality | 2019 |
| Ayouchi AS | Information & communication | 2025 |
| Ayvo AS | Professional & scientific | 2025 |
| B&B Eiendomsutvikling Da | Real estate | 2005 |
| B18 Invest AS | | 2022 |
| Back at IT AS | | 2023 |
| Back Me Up AS | | 2019 |
| Bae Holding AS | | 2024 |
| Bam Consulting AS | Professional & scientific | 2023 |
| Banesupport AS | Professional & scientific | 2018 |
| Bankbygget Wiels Plass AS | Real estate | 1996 |
| Bar Bahalim AS | Hospitality | 2022 |
| Bare Thoresen AS | Real estate | 2005 |
| Bari Invest AS | Wholesale & retail | 2014 |
| Basisfot Halden AS | Health & social care | 2015 |
| Batho AS | | 2011 |
| BD Bygg AS | Construction | 2026 |
| Beamik Holding AS | Professional & scientific | 2025 |
| Beauty by Helene AS | Other services | 2026 |
| Berby Herregård AS | | 2025 |
| Berg Gjenvinning AS | Wholesale & retail | 2007 |
| Berg Idd Og Aremark Regnskapslag SA | Professional & scientific | 1994 |
| Berg Sparebank | Financial services | 1915 |
| Berga Bygg AS | Real estate | 2019 |
| Berger Data Da | Information & communication | 1997 |
| Berglyhallen Møbelhus AS | Wholesale & retail | 2006 |
| Bergsmark Gård Ans | Agriculture & fishing | 2019 |
| Bergstrøm Invest AS | | 2012 |
| Bergstrøm Kjøtt Og Delikatesse AS | Manufacturing | 2001 |
| Bergøy Eiendom AS | Real estate | 2021 |
| Bergøy Kapital AS | | 2021 |
| Bespoke Norway AS | Manufacturing | 2021 |
| Best Melk Samdrift Da | Agriculture & fishing | 2002 |
| Betocut AS | Construction | 2006 |
| BFB AS | Arts & recreation | 2020 |
| Bia Holding AS | | 2019 |
| Bico Ans | Wholesale & retail | 1991 |
| Biddr AS | Information & communication | 2026 |
| Big Invest AS | Real estate | 2005 |
| Big Time Music Da | Arts & recreation | 2014 |
| Bigge Holding AS | Real estate | 2015 |
| Bil & Fritid AS | Administrative & support | 1990 |
| Billboard Bandit AS | Hospitality | 2022 |
| Billebakken Terrasse 29 AS | Real estate | 2020 |
| Billigmarkedet AS | Wholesale & retail | 2023 |
| Billington Eiendom AS | Real estate | 1923 |
| Billingtons Jernvareforretning AS | Wholesale & retail | 1991 |
| Biltrio AS | Wholesale & retail | 2013 |
| Bimco AS | Real estate | 2018 |
| Binspired AS | Education | 2019 |
| Binspired Solutions AS | Real estate | 2020 |
| Bisgaards Skapelse AS | Health & social care | 2022 |
| Bislet Trading AS | Administrative & support | 1986 |
| Bislingen Maskin AS | Construction | 2016 |
| Bisseberg Gård Ans | Agriculture & fishing | 2020 |
| Bitpark AS | Information & communication | 2017 |
| Bjerge Holding AS | | 2021 |
| Bjerge Invest AS | Financial services | 2014 |
| Bjerke Falch Invest AS | | 2026 |
| Bjerkeveien 9 AS | Real estate | 1949 |
| Bjørn Holand AS | Construction | 2019 |
| Bjørn Torp AS | Wholesale & retail | 2004 |
| Bjørndalen Utvikling AS | Real estate | 2020 |
| Blakaj AS | Transport & logistics | 2015 |
| Blikk Media AS | Professional & scientific | 2022 |
| Blikkenslager Frode Dahl AS | Construction | 2019 |
| BLM Auto AS | Wholesale & retail | 2022 |
| Blueberry AS | | 2026 |
| Bo D Petersson Åkeri AB | Administrative & support | 2006 |
| Bo-Hus Eiendom AS | Real estate | 2007 |
| Bobo AS | Real estate | 1988 |
| Body Boutique Halden Ans | Wholesale & retail | 1996 |
| Bohusflyg AB | Manufacturing | 2011 |
| Bolig for Deg AS | Real estate | 2021 |
| Boligbyggelagene Halden Og Moss Sydenboliger AS | Real estate | 2003 |
| Bolstad Mat AS | Wholesale & retail | 2026 |
| Bombus Holding AS | Real estate | 2016 |
| Borg Bygg AS | Real estate | 1986 |
| Borgergata 11 AS | Real estate | 2019 |