| Alex Trafikkskole AS | Education | 2021 |
| Alexa Nor AS | Real estate | 2017 |
| Alf Rishovd AS | Real estate | 1994 |
| Alfa Entreprenør AS | Real estate | 2024 |
| Alfa Royal AS | Information & communication | 2021 |
| Alfa Solskjerming AS | Wholesale & retail | 2005 |
| Alfr. Andersen Eiendom AS | Real estate | 2006 |
| Alice Helena Holding AS | | 2023 |
| Aljoa AS | Information & communication | 2014 |
| All Golf Services Norge AS | Construction | 2021 |
| Allabreve AS | Information & communication | 2006 |
| Allehånde AS | | 2026 |
| Alliance Smart Renhold AS | Administrative & support | 2026 |
| Allium AS | Real estate | 2005 |
| Allmennlegeklinikken AS | Health & social care | 2025 |
| Allmennlegeklinikken Da | Health & social care | 2000 |
| Allsorts Norge AS | Education | 2011 |
| Allumgården AS | Real estate | 1982 |
| Alm Invent AS | Information & communication | 2018 |
| Alminvest AS | | 2021 |
| Almond Group AS | Real estate | 2016 |
| Alpa Eiendomsselskap AS | Professional & scientific | 2013 |
| Alpa Økonomi AS | Professional & scientific | 2008 |
| Alpe Invest AS | Financial services | 2017 |
| Alpenhaus Norge AS | Professional & scientific | 2023 |
| Alphalink AS | Wholesale & retail | 2008 |
| Alstad-Rygg Holding AS | Financial services | 2016 |
| Alt Annet AS | Hospitality | 2010 |
| Alt Asiatisk AS | Arts & recreation | 2023 |
| Alt I Armering AS | Construction | 2019 |
| Alt I Automatisering Limited Nuf | Education | 2013 |
| Altele AS | Wholesale & retail | 2012 |
| Alternativ Drenering AS | Construction | 2020 |
| Altimont AS | Construction | 2013 |
| Altitude Wines AS | Wholesale & retail | 2024 |
| Altrent AS | Administrative & support | 2020 |
| Alunor AS | Wholesale & retail | 2007 |
| Alvens AS | Administrative & support | 2013 |
| Am Partner AS | Arts & recreation | 1994 |
| Amadeus Musikk Drammen AS | Wholesale & retail | 2006 |
| Amanor AS | Administrative & support | 2018 |
| Amb Shoe Consulting AS | Financial services | 2007 |
| Ambiente Consulting AS | Professional & scientific | 2024 |
| Ambition Profile Academy AS | Professional & scientific | 2025 |
| Amedia Annonse Buskerud Og Vestfold AS | Professional & scientific | 2022 |
| Amedia Kundesenter AS | Information & communication | 2003 |
| Ameln Holding AS | | 2023 |
| Ameloni Consult AS | Professional & scientific | 2023 |
| Amerikansk Politikk AS | Arts & recreation | 2024 |
| Amerikanske MC Deler AS | Wholesale & retail | 2024 |
| Amesto Accounthouse Drammen Holding AS | Professional & scientific | 2017 |
| Amesto Accounthouse Sør AS | Professional & scientific | 2013 |
| Amh Consult AS | Professional & scientific | 2005 |
| Amigos Barbershop AS | Other services | 2023 |
| Amore AS | Hospitality | 2021 |
| Amp Holding AS | | 2020 |
| Amp Isolering AS | Construction | 2013 |
| Ampliora AS | Administrative & support | 2026 |
| Ams Utvikling AS | Professional & scientific | 2024 |
| Amseco AS | Construction | 2025 |
| Amseco Holding AS | Construction | 2016 |
| Amthosa Consulting AS | Professional & scientific | 2011 |
| Amtm Blomsgt 22 AS | Real estate | 1981 |
| Amtmand Aallsgt. 85 AS | Real estate | 2011 |
| Amtmann Blomsgate 6-8 AS | Real estate | 2018 |
| Ancient Wines AS | Wholesale & retail | 2024 |
| Andebuveien 78 AS | Real estate | 2005 |
| Anders Kvarme AS | Health & social care | 2017 |
| Anders O. Wang Holding AS | Real estate | 2015 |
| Ando Holding AS | | 2025 |
| Andorsrud Holding AS | Real estate | 2005 |
| Andr Thorkildsen Husfliden AS | Wholesale & retail | 1944 |
| Andreas Hartz AS | Administrative & support | 2018 |
| Andreassen Eiendomsutvikling AS | Real estate | 2020 |
| Andreassen Elektro AS | Construction | 2004 |
| Andrè Solvang Racing AS | Arts & recreation | 2021 |
| Anetme AS | | 2024 |
| Angelica Westerberg AS | Education | 2026 |
| Angell-Invest AS | | 2021 |
| Angstroem AS | Information & communication | 2018 |
| Anicic Invest AS | | 2020 |
| Animation & Crafts AS | Health & social care | 2025 |
| Anle AS | Administrative & support | 2015 |
| Anleggsgartner Bjørn T Bjerknes AS | Administrative & support | 2018 |
| Anleggsgartnermester Øivind Kofstad AS | Administrative & support | 2000 |
| Anmano Holding AS | Financial services | 2018 |
| Anna-Lisa Entertainment AS | Arts & recreation | 2025 |
| Anna-Sofie AS | Professional & scientific | 2026 |
| Anne Invest AS | | 2023 |
| Annes AS | Wholesale & retail | 2025 |
| Annwa Holding AS | | 2026 |
| Ans Bøckmann & Markussen Voksenopplæring | Education | 1989 |
| Ans Nedre Storgt 14 | | 1989 |
| Ans Steenland | | 1989 |
| Ans Trimmen Fysikalske | Health & social care | 1991 |
| Ans Øvre Storg 54 | | 1989 |
| Ansatt I Mjøndalen Apotek AS | Administrative & support | 2018 |
| Anshi AS | Wholesale & retail | 2024 |
| Anthonie Opsahl Schnell Holding AS | | 2025 |
| Anton Engensvei 3 AS | Real estate | 2023 |