| Abacus PLM Solutions AS | Professional & scientific | 2015 |
| Abato AS | Real estate | 2010 |
| Abb Rådgivere AS | Professional & scientific | 2025 |
| Abbeyfeale AS | | 2025 |
| Abbriva Invest AS | Real estate | 2005 |
| Abc Bolig Norge AS | Real estate | 2020 |
| Abc Tannklinikken AS | Health & social care | 2011 |
| Abcdef Kapital AS | | 2025 |
| Abed Nego AS | Real estate | 2012 |
| Abel Consult AS | Real estate | 1990 |
| Abelgården Tannklinikk AS | Health & social care | 1998 |
| Abelsborg Gate 10 AS | Real estate | 2024 |
| Abelsborg Gate 10 Holding AS | | 2025 |
| Abeltun & Partnere AS | Financial services | 2024 |
| Abes Trafikkskole AS | Education | 2007 |
| Abicon AS | Professional & scientific | 1987 |
| Abide AS | | 2006 |
| Abilator AS | Professional & scientific | 2015 |
| Abk Consulting AS | Professional & scientific | 2024 |
| Abl Eiendom AS | Real estate | 2023 |
| Ablasjonsbehandling AS | Health & social care | 2026 |
| Able Humans AS | Professional & scientific | 2022 |
| Ablemagic AS | Information & communication | 2007 |
| Abra Beslag AS | Wholesale & retail | 2010 |
| Abrahams Hus AS | Construction | 2016 |
| Absilon AS | Financial services | 2011 |
| Abysshaul Da | Information & communication | 2024 |
| Acb Auto-Media AS | Wholesale & retail | 1985 |
| Accendio AS | Real estate | 2024 |
| Accendio Clinic AS | Health & social care | 2026 |
| Accensus AS | Real estate | 1991 |
| Access Systems AS | Wholesale & retail | 2016 |
| Accommodate AS | Administrative & support | 2013 |
| Accountech AS | Professional & scientific | 2025 |
| Ace Accounting AS | Professional & scientific | 2024 |
| Ace Asiamat Restaurant AS | Hospitality | 2022 |
| Ace Økonomipartner AS | Professional & scientific | 2021 |
| Acedia Works AS | Information & communication | 2026 |
| Acm AS | Financial services | 2005 |
| Acoustic Landscapes AS | Arts & recreation | 2013 |
| Acoustic Tuning AS | Wholesale & retail | 2016 |
| Acr Holding AS | | 2019 |
| Acreage AS | | 2025 |
| Acrylicon Holding AS | Wholesale & retail | 2005 |
| Acrylicon Norge AS | Wholesale & retail | 1992 |
| Activate Games Bergen AS | Arts & recreation | 2025 |
| Activate Games Oslo 2 AS | Arts & recreation | 2025 |
| Activate Games Oslo AS | Arts & recreation | 2025 |
| Activate Games Scandinavia AS | Arts & recreation | 2022 |
| Active Holding AS | | 2025 |
| Ad Holdning AS | | 2024 |
| Ada AS | Administrative & support | 2024 |
| Adam Holding AS | | 2023 |
| Add Venture AS | Professional & scientific | 2017 |
| Adekvat Eiendom AS | Real estate | 2023 |
| Adepta AS | Health & social care | 2012 |
| Adepten AS | Construction | 2022 |
| Ader Sports AS | Professional & scientific | 2013 |
| Adinfernum AS | Wholesale & retail | 2004 |
| Adjuva AS | Information & communication | 2012 |
| Adlibit AS | Information & communication | 2014 |
| Adlock Norge AS | Construction | 2010 |
| Admaso Holding AS | | 2012 |
| Admo AS | Professional & scientific | 2025 |
| Admtek AS | Professional & scientific | 2007 |
| Adnor Advokat AS | Professional & scientific | 2011 |
| Ado Nordic | Wholesale & retail | 2007 |
| Adresseavisen AS | Information & communication | 2008 |
| Adresseavisens Gravefond AS | Other services | 2025 |
| Adresseavisens Telefontjenester AS | Administrative & support | 1999 |
| Adrian Holding 1 AS | | 2026 |
| Adrian S. Asli AS | | 2026 |
| Advanced Biopolymers AS | Professional & scientific | 2001 |
| Advanced Media Ans | Information & communication | 2002 |
| Advans Medical AS | Health & social care | 2025 |
| Adventales AS | Information & communication | 2019 |
| Adventures Barcelona AS | Administrative & support | 2014 |
| Advo-Casa AS | Real estate | 1985 |
| Advokat Camilla Ødegaard Letnes AS | Professional & scientific | 2017 |
| Advokat Ellen Ulriksen AS | Professional & scientific | 2021 |
| Advokat Erik Vatne AS | Professional & scientific | 2020 |
| Advokat Geir Hegle AS | Professional & scientific | 2005 |
| Advokat Karlgård AS | Professional & scientific | 2026 |
| Advokat Kolbjørn Lium AS | Professional & scientific | 2021 |
| Advokat Leif Strøm AS | Professional & scientific | 2003 |
| Advokat Marcus Amdahl AS | Professional & scientific | 2018 |
| Advokat Mats Haugen AS | | 2026 |
| Advokat Sivertsvik AS | Professional & scientific | 2014 |
| Advokat Svarva AS | Professional & scientific | 2019 |
| Advokat Tor Rikard Evensen AS | Professional & scientific | 2014 |
| Advokat Tore Sveen AS | | 2005 |
| Advokatene Christian Wiig & Co AS | Professional & scientific | 2005 |
| Advokatfirma Siv Aida Rui AS | Professional & scientific | 2026 |
| Advokatfirmaet A.B AS | Professional & scientific | 2024 |
| Advokatfirmaet Amidu AS | Professional & scientific | 2020 |
| Advokatfirmaet Fredriksen AS | Professional & scientific | 2022 |
| Advokatfirmaet Hopsø AS | Professional & scientific | 2024 |
| Advokatfirmaet Kolbjørnsen Cyvin AS | Professional & scientific | 2016 |
| Advokatfirmaet Melø AS | Professional & scientific | 2022 |
| Advokatfirmaet Nidaros Da | Professional & scientific | 2002 |