| 1001 Ting Lillestrøm Ans | | 1989 |
| 111 Holding AS | Wholesale & retail | 2024 |
| 24/7 Bilvask AS | Other services | 2024 |
| 2R Data Og Regnskap AS | Professional & scientific | 1989 |
| 2S Bygg AS | Construction | 2016 |
| 3HUS AS | Construction | 2012 |
| 3K Holding AS | Real estate | 2005 |
| 3M Norge AS | Wholesale & retail | 1961 |
| 4 Eiendom AS | Financial services | 2018 |
| 4 Goblets AS | Hospitality | 2022 |
| 4BIT Games AS | Information & communication | 2015 |
| 4S Business Consulting AS | Professional & scientific | 2020 |
| 9NA Holding AS | | 2021 |
| A C Svarstads Gate Garasjelag SA | Real estate | 1980 |
| A Holdings AS | | 2020 |
| A Management AS | | 2005 |
| A Sports AS | Professional & scientific | 2018 |
| A Til Å Invest AS | Real estate | 2024 |
| A Til Å Regnskap AS | Professional & scientific | 2004 |
| A Til Å-Eiendom AS | | 2024 |
| A+ Words AS | Professional & scientific | 2025 |
| A. Møller Invest AS | Professional & scientific | 2019 |
| A.T Holding AS | | 2026 |
| Aaha AS | | 2023 |
| Aahm Invest AS | Other services | 2021 |
| Aava Holding AS | | 2022 |
| Abc Bil AS | Other services | 2023 |
| Abc Bilsalg AS | Wholesale & retail | 2024 |
| Abc Deler AS | Wholesale & retail | 2024 |
| Abel Tolketjeneste AS | | 2019 |
| Abl Service AS | Construction | 2024 |
| Abu Entreprenør AS | Real estate | 2010 |
| Abzolutt Interiør AS | Real estate | 2024 |
| Accascon AS | | 2022 |
| Accelat AS | Information & communication | 2019 |
| Achieved AS | Information & communication | 2026 |
| Achieved Da | Information & communication | 2016 |
| Ad Infinitum AS | | 2023 |
| Adaptive Edge Technologies AS | Administrative & support | 2022 |
| Adcomer AS | Professional & scientific | 2022 |
| Adec Økonomi AS | Professional & scientific | 2014 |
| Ademin Beauty AS | Other services | 2024 |
| Admin AS | Professional & scientific | 1990 |
| Advokatdirekte AS | Professional & scientific | 2005 |
| Advokatfirmaet Halvorsen & Co AS | Professional & scientific | 2008 |
| Advokatfirmaet Lærum, Lier, Stende & Berven AS | Professional & scientific | 1997 |
| Advokatfirmaet Møller AS | Professional & scientific | 2018 |
| Advokatfirmaet Saar AS | Professional & scientific | 2021 |
| Advokatfirmaet Tønset AS | Professional & scientific | 2011 |
| Advokatfirmaet Økland & Co AS | Professional & scientific | 2024 |
| Ae Finnsnes AS | Real estate | 2019 |
| Ae Harstad Hjelpeselskap AS | Real estate | 2023 |
| Ae Lier AS | Real estate | 2023 |
| Ae Lillehammer AS | Real estate | 2023 |
| Ae Lillehammer Hjelpeselskap AS | Real estate | 2023 |
| Ae Tunga AS | Real estate | 2019 |
| Aer Labs AS | Information & communication | 2025 |
| Afa Depeche Invest AS | Real estate | 2018 |
| Afa Depeche Invest Holding AS | | 2023 |
| Afrinord Consult AS | Professional & scientific | 2026 |
| AG Invest 1 AS | | 2021 |
| Ager Kontor Da | Wholesale & retail | 2007 |
| Agf-Art AS | Arts & recreation | 2018 |
| Agis Fire & Security (Denmark) | Wholesale & retail | 1995 |
| Agri Eiendom AS | Real estate | 2004 |
| Agri Eiendom Stavanger AS | Real estate | 2003 |
| Agros AS | Information & communication | 2022 |
| Ahgt Invest AS | | 2025 |
| Aidartists AS | Information & communication | 2021 |
| Ainnovate AS | Information & communication | 2014 |
| Ajk AS | Real estate | 1971 |
| Ak Bygg Og Montasje AS | Construction | 2023 |
| Aka Group AS | Real estate | 2002 |
| Akershus Byggmesterforretning AS | Construction | 1995 |
| Akershus Connect AS | Information & communication | 2009 |
| Akershus Energi AS | Energy | 1996 |
| Akershus Energi Batteri & Lading AS | | 2026 |
| Akershus Energi Investeringer AS | Professional & scientific | 2016 |
| Akershus Energi Vannkraft AS | Energy | 1996 |
| Akershus Energi Varme AS | Energy | 2001 |
| Akershus Energi Vind AS | Professional & scientific | 2019 |
| Akershus Teknologifond AS | Financial services | 2008 |
| Akershus VVS Eiendom AS | Real estate | 2016 |
| Akram Zalmai Ans | Real estate | 2003 |
| Aksjeklubben Avidus Ans | | 2025 |
| Aksjeselskapet Esperanza | Transport & logistics | 1936 |
| Akuro AS | Construction | 2017 |
| AKV3 AS | Real estate | 2023 |
| Akz Holding AS | | 2024 |
| Alan's Barber Shop AS | Other services | 2023 |
| Alb Byggservis AS | Construction | 2013 |
| Alden Forvaltning AS | Financial services | 2012 |
| Aleksander Sætre Holding AS | Real estate | 2007 |
| Alexander Kiellandsgate 10 AS | Real estate | 2005 |
| Alfa Bolig AS | Real estate | 2022 |
| Alfa Prosjekt AS | Real estate | 2023 |
| Alfaflow AS | Professional & scientific | 2013 |
| Alfasoft AS | Wholesale & retail | 2002 |
| Alfasoft Holding AS | Financial services | 2014 |
| Alfsen Mek. Verksted AS | Manufacturing | 2013 |