| Asoka AS | Health & social care | 1998 |
| Assi AS | Construction | 2023 |
| At Eiendom Drøbak AS | Real estate | 1996 |
| At Event AS | Administrative & support | 2026 |
| Atg Invest AS | | 2025 |
| ATHENEX360 AS | Information & communication | 2024 |
| Athletix AS | Wholesale & retail | 2020 |
| Atlas Shrugged Advisory AS | Professional & scientific | 2008 |
| Audentia AS | Health & social care | 2005 |
| Audiovision AS | Administrative & support | 2022 |
| Aunoma Holding AS | Real estate | 2010 |
| Aura Hair Drøbak AS | Other services | 2025 |
| Auto Klar AS | Wholesale & retail | 2024 |
| Auto Noor Bilsenter AS | Wholesale & retail | 2022 |
| Auto-Teknikk Drøbak AS | Other services | 2001 |
| Autobilmester AS | Wholesale & retail | 2025 |
| Avi Elektro AS | Construction | 2017 |
| Avi Properties AS | Real estate | 2023 |
| Aviator Holding AS | | 2022 |
| Avicma Invest AS | Financial services | 2016 |
| Avrot AS | Wholesale & retail | 2025 |
| Axel Brun Invest AS | Manufacturing | 2005 |
| B Invest AS | Real estate | 2007 |
| B&K International AS | Wholesale & retail | 2005 |
| B.E.K.K. Event AS | Hospitality | 2015 |
| B30 Holding AS | Real estate | 2020 |
| BA10RI AS | | 2024 |
| Babylon Grill AS | Hospitality | 2018 |
| Backoffice Regnskap Og Rådgivning AS | Professional & scientific | 2005 |
| Bade Consulting AS | Construction | 2007 |
| Bafam Invest AS | | 2025 |
| Balder Construction Development AS | Real estate | 2019 |
| Balder Holding Group AS | Information & communication | 2008 |
| Baltz Invest AS | Real estate | 2022 |
| Baltztek AS | Construction | 2015 |
| Barlind Holding AS | Financial services | 2007 |
| Barnas Plattform AS | Education | 2015 |
| Barneskatter Ski AS | Wholesale & retail | 2021 |
| Barzaria AS | Transport & logistics | 2023 |
| Baste Eiendom Ltd Nuf | Construction | 2006 |
| BB AS | Real estate | 1985 |
| Bbas Holding AS | Construction | 2025 |
| Bbholding AS | | 2026 |
| Be-St Snekkerverksted Ans | Manufacturing | 1991 |
| Bedre Betingelser AS | Professional & scientific | 1999 |
| Bedre Oppvekst AS | Health & social care | 2021 |
| Bedre Plass AS | Real estate | 2017 |
| Bedriftsrådgiver Sandnes AS | Professional & scientific | 2008 |
| Bella Vista Drøbak AS | Hospitality | 2025 |
| Bena Bygg AS | Construction | 2022 |
| Bent Karlsen Holding AS | Wholesale & retail | 2000 |
| Beredskapspartner AS | Wholesale & retail | 2025 |
| Berg-Andersen AS | Wholesale & retail | 1989 |
| Berga AS | Real estate | 2009 |
| Bergem & Røstvold Holding AS | Professional & scientific | 2013 |
| Berve Invest AS | | 2021 |
| Bettman Holding AS | Real estate | 2005 |
| Bfhr AS | Information & communication | 2019 |
| BG Eiendom II AS | Real estate | 2020 |
| Bido Finans AS | Professional & scientific | 2005 |
| Bigbear Communications AS | Information & communication | 2005 |
| Bil & Magnetprodukter AS | Wholesale & retail | 1971 |
| Billing AS | Financial services | 2013 |
| Bimas Invest AS | | 2005 |
| Bio Brokers AS | Wholesale & retail | 2016 |
| Biovita AS | Wholesale & retail | 2006 |
| Bivio AS | Professional & scientific | 2014 |
| Bjela AS | Financial services | 2016 |
| Bjelland Capital I AS | Real estate | 2020 |
| Bjerkeveien Barnehage SA | Education | 2004 |
| Bjønness-Bygg 2 AS | Construction | 2026 |
| Bjønness-Bygg AS | Construction | 1985 |
| Bjørke Holding AS | Information & communication | 2014 |
| Bjørn Gregersen Invest AS | | 2019 |
| BLS AS | Wholesale & retail | 2021 |
| Body Map AS | Wholesale & retail | 2005 |
| Bogstadveien 60 AS | Real estate | 2008 |
| Boldevin AS | | 2021 |
| Boligstyret.No AS | Wholesale & retail | 2014 |
| Boliér AS | Construction | 2017 |
| Boot Room Invest AS | | 2024 |
| Bopartner AS | Real estate | 2009 |
| Bopartner Utvikling AS | Real estate | 2013 |
| Bottles AS | Wholesale & retail | 2022 |
| Bounce AS | Health & social care | 2012 |
| Brabus AS | | 2016 |
| Bradford Holding AS | Financial services | 2012 |
| Brand Store AS | Wholesale & retail | 2019 |
| Brannsæther Bygg & Eiendomsservice AS | Construction | 2020 |
| Brekkeveien 61 AS | Real estate | 1975 |
| Brekkeveien 61 Bolig AS | Real estate | 2021 |
| Brenden & Co Consulting AS | Professional & scientific | 2014 |
| Brenden Eiendom AS | Real estate | 2014 |
| Brendvold Eiendom AS | Real estate | 2012 |
| Bringebærlandet AS | Agriculture & fishing | 2026 |
| Britanniatorget Legesenter Da | Health & social care | 2005 |
| Brom Consulting AS | Wholesale & retail | 2014 |
| Bruktbil Drøbak AS | Wholesale & retail | 2025 |
| Brødrene Hjorteset AS | Real estate | 2006 |
| Bukta Invest AS | Financial services | 2005 |