| 100BIRDIES AS | Arts & recreation | 2026 |
| 3M3A Global AS | Professional & scientific | 2019 |
| A2 Partner AS | Professional & scientific | 2012 |
| Aakob Holding AS | Information & communication | 2022 |
| AB Investment AS | Professional & scientific | 2005 |
| Abili AS | Real estate | 2014 |
| Abs Invest AS | Real estate | 2004 |
| Aceza Solutions AS | Professional & scientific | 2023 |
| Aconcagua AS | Financial services | 2011 |
| Advanced International Management AS | Professional & scientific | 2000 |
| Advokat Mollestad Oppegaard AS | Professional & scientific | 2017 |
| Advokatfirma Capri AS | Professional & scientific | 2009 |
| Advt AS | | 2019 |
| Ae Finans AS | Real estate | 2018 |
| Ae Holdings AS | | 2023 |
| Ae Ventures AS | Real estate | 2013 |
| Affinitet AS | Professional & scientific | 2020 |
| Again and Again AS | Wholesale & retail | 2026 |
| Akershus Gourmet AS | Hospitality | 2025 |
| Alien Film AS | Education | 2000 |
| Alinea Holding AS | Financial services | 2005 |
| Allivo AS | Real estate | 2025 |
| Alme Invest AS | Financial services | 2013 |
| Altiora Capital AS | | 2025 |
| Am Halaas Holding AS | | 2020 |
| Amanpuri AS | Real estate | 2014 |
| Amatu AS | Information & communication | 2023 |
| Amborg AS | | 2022 |
| Amland Spesialist Legetjenester AS | Health & social care | 1995 |
| Amphytron Invest AS | Real estate | 2007 |
| Amra Holding AS | Real estate | 2021 |
| Ancasco AS | | 2017 |
| Andbek AS | Professional & scientific | 2006 |
| Anterior AS | Information & communication | 2026 |
| Anton Invest AS | Wholesale & retail | 2004 |
| Anunnaki Invest AS | Real estate | 2021 |
| Aoc Holding AS | | 2015 |
| Appletify AS | Information & communication | 2015 |
| Aprosess AS | Professional & scientific | 2005 |
| Aramco AS | Professional & scientific | 2009 |
| Arenfeldtsvei 12 AS | Real estate | 2014 |
| Arjo AS | Real estate | 2021 |
| Arnico Holding AS | Real estate | 2019 |
| Artes AS | Real estate | 2024 |
| AS Curlingbaner | Arts & recreation | 1973 |
| AS Servo | Real estate | 1957 |
| AS Servotrading | Wholesale & retail | 1981 |
| AS Strømstangen Boligselskap | Households | 1950 |
| AS Øya | Real estate | 1949 |
| Asker Boligeiendom AS | Real estate | 2019 |
| Askim Bedriftsmegling AS | Professional & scientific | 1999 |
| Asmar AS | Real estate | 2021 |
| Atlas Trading AS | Real estate | 2009 |
| Avenco AS | Wholesale & retail | 2005 |
| Axon Invest AS | Health & social care | 2014 |
| B10 Consulting AS | Professional & scientific | 2016 |
| B10 Holding AS | Professional & scientific | 2016 |
| Balnagown Holding AS | | 2023 |
| BASE8 AS | | 2024 |
| Baubo Worldwide AS | | 2026 |
| Bauta Studios AS | Professional & scientific | 2023 |
| Becks Invest AS | | 2021 |
| Beco AS | Real estate | 1993 |
| Belleza Invest AS | | 2018 |
| Berdal AS | | 2021 |
| Bergenstjerna Kapital AS | Information & communication | 2024 |
| Berglind Invest AS | Real estate | 2006 |
| Bergly Invest AS | Financial services | 2004 |
| Bergrådveien 13 Eiendom & Finans AS | Real estate | 1969 |
| Bergrådveien 13 Invest AS | Real estate | 2011 |
| Bergshammeren AS | Financial services | 2009 |
| Bergshammeren Holding AS | | 2023 |
| Bernstein Invest AS | Real estate | 2015 |
| Bibadum AS | Health & social care | 2006 |
| Biotic AS | Health & social care | 2014 |
| Birk Investment AS | Financial services | 2005 |
| Birk Venture AS | Financial services | 2010 |
| Birkelunden Spillekiosk Ans | Wholesale & retail | 1985 |
| Bitte Holding AS | | 2020 |
| Bjelke Consulting AS | Financial services | 2005 |
| Bjørbu Holding AS | Real estate | 1997 |
| Bjørum AS | Real estate | 1998 |
| Bleikvin AS | Financial services | 2005 |
| Bliki AS | | 2019 |
| Blue AS | Information & communication | 2004 |
| Body Green AS | Wholesale & retail | 2018 |
| Bohan & Co AS | Professional & scientific | 2005 |
| Bojo Industries AS | Construction | 2005 |
| Bojo Invest AS | Construction | 2017 |
| Bojo Re AS | Real estate | 2017 |
| Bojo Shipping AS | Construction | 2013 |
| Bond AS | Professional & scientific | 2026 |
| Borkenveien 20-24 Holding AS | Real estate | 2025 |
| Boscon AS | | 2020 |
| Box Holding AS | Wholesale & retail | 2007 |
| Bratsberg Invest AS | Real estate | 2005 |
| Bratsberg Kapital AS | Real estate | 2020 |
| Braut Holding AS | | 2020 |
| Brint AS | | 2020 |
| Briskebyveien 38 Da | Real estate | 1995 |