| 123 Regnskap AS | Professional & scientific | 2023 |
| 2ABRA AS | Professional & scientific | 2022 |
| 2TAL AS | Construction | 1989 |
| A & B Holding AS | | 2020 |
| A Kristiansen Holding AS | Financial services | 2011 |
| A Nilsen AS | Construction | 2021 |
| A Sørensen AS | Transport & logistics | 2019 |
| A-B Trafikkskole AS | Education | 2013 |
| A. Hoaas Holding AS | Wholesale & retail | 2018 |
| A.K. Snekring AS | Construction | 2016 |
| A12 Eiendom AS | Real estate | 2013 |
| A2BUS AS | Transport & logistics | 2008 |
| A390 Prosjekt AS | Real estate | 2021 |
| Aarja Health AS | Wholesale & retail | 2020 |
| Aarja Health Holding AS | Wholesale & retail | 2021 |
| Aas Blooming AS | Other services | 2025 |
| Abos AS | Real estate | 2021 |
| Abreu Holding AS | | 2021 |
| Abs Ønh AS | Health & social care | 2024 |
| Ac Service AS | Construction | 2022 |
| Adamsen Holding AS | Real estate | 2020 |
| Adas Bygg AS | Construction | 2022 |
| Adas Invest AS | | 2025 |
| Advanti & Partners Alta AS | Real estate | 2020 |
| Advokat Espen Simonsen AS | Professional & scientific | 2015 |
| Advokat Gisle Loso AS | Professional & scientific | 2010 |
| Advokat Jørn Eikanger AS | Professional & scientific | 2005 |
| Advokat Kjetil H. Nilsen AS | Professional & scientific | 2006 |
| Advokat Line Hammari AS | Professional & scientific | 2005 |
| Advokatfirmaet Hegg & Co AS | Professional & scientific | 2005 |
| Advokatselskapet Hoaas AS | Professional & scientific | 2020 |
| Ae Kapital AS | Other services | 2020 |
| Ae Motor & Bilservice AS | Other services | 2021 |
| Afe AS | Real estate | 2010 |
| Afl Holding AS | Mining & quarrying | 2018 |
| Afrodite Beautysalong Og Parfymeri AS | Other services | 1998 |
| Aft Entreprenør AS | Construction | 2020 |
| Agel Eiendom AS | Real estate | 1981 |
| Ahol-Holding AS | | 2021 |
| Aili AS | Other services | 2026 |
| Aim for Active AS | Health & social care | 2011 |
| Aja Eiendom AS | Real estate | 2022 |
| Ak Kristensen AS | Real estate | 2021 |
| Ak Maskin AS | Construction | 2024 |
| Akr Eiendom AS | Real estate | 2011 |
| Aksa El AS | Construction | 2020 |
| Aksa Hjem AS | Information & communication | 2020 |
| Aksa Vann AS | Energy | 2020 |
| Aksis Arbeidsinkludering AS | Health & social care | 2022 |
| Aksis AS | Health & social care | 1970 |
| Aksis Kompetanse AS | Health & social care | 2022 |
| Akt Eiendom Alta AS | Real estate | 2017 |
| Aktiv Kiropraktikk AS | Health & social care | 2012 |
| Akvanorth AS | Agriculture & fishing | 2022 |
| Akvanorth Farm AS | Agriculture & fishing | 2022 |
| Akvanorth Øksfjord AS | Agriculture & fishing | 2022 |
| AL365 Eiendom AS | Real estate | 2025 |
| Alattio Holding AS | | 2026 |
| Albbas AS | Information & communication | 1998 |
| Alexandersen Eiendom AS | Real estate | 2005 |
| Alfheimvegen 1B AS | Real estate | 2020 |
| Alfon Kåre Engro AS | Wholesale & retail | 1994 |
| Algiz AS | Information & communication | 2022 |
| Alice Alta AS | Wholesale & retail | 2004 |
| Allvet AS | Professional & scientific | 2016 |
| Allvet Dyresykehus AS | Professional & scientific | 2014 |
| Alma Halses Vei 1 AS | Real estate | 2017 |
| Alma Utvikling AS | Professional & scientific | 2026 |
| Alsèn Holding AS | Real estate | 2016 |
| Alt a Rør AS | Construction | 2004 |
| Alt'A Solskjerming AS | Wholesale & retail | 2020 |
| Alta Adventure AS | Arts & recreation | 2016 |
| Alta Aktivum AS | Other services | 2004 |
| Alta Anlegg & Industriservice AS | Manufacturing | 2020 |
| Alta Anlegg AS | Construction | 2023 |
| Alta Arena Utvikling AS | Real estate | 2012 |
| Alta Aurora Apartments AS | Real estate | 2025 |
| Alta Autoservice AS | Other services | 2017 |
| Alta Bedriftsmassasje AS | Other services | 2014 |
| Alta Begravelsesbyrå AS | Other services | 2000 |
| Alta Bergingssenter Ans | Transport & logistics | 2005 |
| Alta Bergningssenter AS | Transport & logistics | 2017 |
| Alta Billakkering AS | Other services | 1987 |
| Alta Bilutleie Ans | Administrative & support | 1991 |
| Alta Bilvask Og Bilpleie AS | Other services | 2020 |
| Alta Blikk AS | Construction | 2006 |
| Alta Blomster Og Dekor AS | Wholesale & retail | 2020 |
| Alta Bowling Senter AS | Arts & recreation | 2005 |
| Alta Burger Restaurant AS | Hospitality | 2026 |
| Alta Bygg AS | Construction | 2016 |
| Alta Byggservice AS | Construction | 2018 |
| Alta Caravan AS | Wholesale & retail | 2007 |
| Alta Dyreklinikk AS | Professional & scientific | 2020 |
| Alta Dyreklinikk Eiendom AS | Real estate | 2002 |
| Alta Eiendom AS | Real estate | 2022 |
| Alta El AS | Construction | 1997 |
| Alta Elektro AS | Construction | 2008 |
| Alta Elhandel AS | Wholesale & retail | 2025 |
| Alta Event AS | Arts & recreation | 2011 |
| Alta Event Og Teltutleie Da | Administrative & support | 2006 |