| Anders Bruce Holding AS | Financial services | 2005 |
| Aniesta Sport AS | Wholesale & retail | 2020 |
| Anixter Norge Ans | Wholesale & retail | 1997 |
| Anker Handel AS | Professional & scientific | 2018 |
| Anleggsgartner Armand Iversen AS | Administrative & support | 2016 |
| Annebe Asker AS | Wholesale & retail | 2015 |
| Ans Hobby-Bua Brdr Kase | | 1990 |
| ANS L K Senteret | Real estate | 1988 |
| Antennaco Norway AS | Professional & scientific | 2025 |
| Antikk Møbelrestaurering AS | Other services | 1998 |
| Antiquus Boutique&Café AS | Wholesale & retail | 2026 |
| Antivo IT TMS AS | Information & communication | 2017 |
| Apex AI AS | Information & communication | 2026 |
| Apex-Holding AS | Wholesale & retail | 2023 |
| Appdrift AS | Information & communication | 2026 |
| Appelsin Media AS | Information & communication | 2021 |
| Appkon AS | Professional & scientific | 2022 |
| Appoint AS | Administrative & support | 2010 |
| Approved Brands AS | Wholesale & retail | 2019 |
| April AS | Professional & scientific | 2019 |
| Aq Compute Norway AS | Information & communication | 2022 |
| Aqua Alarm AS | Professional & scientific | 2016 |
| Aram Investeringen AS | Real estate | 2025 |
| Arba Holding AS | Real estate | 2005 |
| Arbeidsfellesskapet Bes Skaaret Ans | Construction | 2018 |
| Arbeidsfellesskapet SL Skaaret Ans | Construction | 2025 |
| Arbengrat Invest AS | | 2020 |
| Archway AS | Professional & scientific | 2015 |
| Arctic Exploration AS | Professional & scientific | 2022 |
| Arctic Motion AS | Professional & scientific | 2025 |
| Arel Da | Professional & scientific | 2010 |
| Ares AS | Professional & scientific | 1997 |
| Ark Eiendom AS | Real estate | 1993 |
| Arkhimedes AS | Professional & scientific | 2002 |
| Arkinova AS | Professional & scientific | 2005 |
| Armalie AS | Professional & scientific | 2017 |
| Armatec AS | Wholesale & retail | 1990 |
| Arne Wenger JR Og Jørn Wenger Ans | Agriculture & fishing | 1996 |
| Arpi Holding AS | Administrative & support | 2000 |
| AS Barnas Hus Gullhella | Education | 1971 |
| AS Bedriftskontakt | Professional & scientific | 1978 |
| AS Best AS | | 2024 |
| AS Folkehallen På Risenga | Arts & recreation | 2021 |
| AS Hofstadgaten 60 | Real estate | 2022 |
| AS Mecana | Professional & scientific | 1944 |
| AS Strøm Invest | Real estate | 1974 |
| Asah AS | Financial services | 2009 |
| Ask Bolig AS | Real estate | 2019 |
| Ask Bygg Entreprenør AS | Construction | 2024 |
| Ask Frisør AS | Other services | 2019 |
| Ask Interiør AS | Wholesale & retail | 2014 |
| Askar Holding AS | Professional & scientific | 2005 |
| Asker & Bærum Grunnmur AS | Construction | 2019 |
| Asker & Bærum Klinikken AS | Real estate | 2015 |
| Asker & Bærum VVS AS | Construction | 2014 |
| Asker Advokatkontor AS | Professional & scientific | 2015 |
| Asker AI Consult AS | Information & communication | 2020 |
| Asker Arkitektkontor AS | Professional & scientific | 2025 |
| Asker Auto Care AS | Other services | 2024 |
| Asker Bandage AS | Wholesale & retail | 2024 |
| Asker Barber Shop AS | Other services | 2021 |
| Asker Begravelsesbyrå AS | Other services | 2020 |
| Asker Bilutleie AS | Administrative & support | 1982 |
| Asker Blomster AS | Wholesale & retail | 1986 |
| Asker Båt Og Motorservice AS | Manufacturing | 1996 |
| Asker Contract Manufacturing AS | Manufacturing | 2022 |
| Asker Couture AS | Manufacturing | 2020 |
| Asker Driftsmateriell Nuf | Wholesale & retail | 2004 |
| Asker Eiendomsmegling AS | Real estate | 2022 |
| Asker Eiendomsutleie AS | Real estate | 2005 |
| Asker Eiendomsutvikling AS | Real estate | 2019 |
| Asker El-Installasjon AS | Construction | 2025 |
| Asker Elektriske AS | Construction | 2008 |
| Asker Elektriske Eiendom AS | Real estate | 1976 |
| Asker Elektro Diesel AS | Other services | 1989 |
| Asker Estetikk & Gynklinikk AS | Health & social care | 2025 |
| Asker Fargehandel AS | Wholesale & retail | 2024 |
| Asker Fargehandel Holding AS | | 2024 |
| Asker Fotballfest AS | Administrative & support | 2023 |
| Asker Fys Med AS | Health & social care | 2011 |
| Asker Fysikalsk Helse AS | Health & social care | 2026 |
| Asker Glassmesterforretning AS | Construction | 1982 |
| Asker Golfbane AS | Real estate | 1993 |
| Asker Gro AS | Hospitality | 2013 |
| Asker Gull Sølv Ur AS | Wholesale & retail | 1995 |
| Asker Hageservice AS | Administrative & support | 2014 |
| Asker Helse Ans | Health & social care | 2003 |
| Asker Helsesenter AS | Health & social care | 2020 |
| Asker Herreekvipering-Bauer AS | Wholesale & retail | 1963 |
| Asker Herrefrisør AS | Other services | 2022 |
| Asker Hud Og Velvære AS | Other services | 2018 |
| Asker Hydraulikk AS | Manufacturing | 2017 |
| Asker Håndverk Bolig AS | Real estate | 2021 |
| Asker Håndverk Gruppen AS | Construction | 2011 |
| Asker Industri Service AS | Professional & scientific | 2025 |
| Asker IT Consulting AS | Information & communication | 2014 |
| Asker Kattehotell AS | Agriculture & fishing | 2012 |
| Asker Kebabhus AS | Hospitality | 2019 |
| Asker Kompetanse AS | Health & social care | 2025 |
| Asker Konferansesenter AS | Real estate | 2000 |