| Af Kverndalen Ans | Construction | 2020 |
| Afrodite Holding AS | Real estate | 2020 |
| Agatha AS | Financial services | 2010 |
| Agato 1 AS | Real estate | 2024 |
| Agato 2 AS | Real estate | 2024 |
| Agato Eiendom AS | Real estate | 2020 |
| Agato Skien AS | Real estate | 2019 |
| Agato Utleie AS | Real estate | 2024 |
| Agentio AS | Real estate | 2026 |
| Agere Trafikkskole AS | Education | 2019 |
| Agility AS | Manufacturing | 2000 |
| Agresso AS | Real estate | 2012 |
| Ah Maskin AS | Construction | 2022 |
| Ah Ventilasjon AS | Construction | 2020 |
| Ah-Transport AS | Construction | 2026 |
| Ahp Consulting AS | Professional & scientific | 2016 |
| Aiga Invest AS | Professional & scientific | 2018 |
| Aimsales Mahamed Limited Nuf | Wholesale & retail | 2025 |
| Aina S Stene AS | Wholesale & retail | 2017 |
| Ajour Holding AS | Real estate | 2020 |
| Ak Skog AS | Agriculture & fishing | 2008 |
| Ak Solid Ground Ans | Administrative & support | 2026 |
| Ak Takservice AS | Construction | 2024 |
| Akda Invest AS | | 2025 |
| Akeo AS | Information & communication | 2009 |
| Albaalba Holding AS | Hospitality | 2024 |
| Albjerk Invest AS | Construction | 2006 |
| Albjerk Konsult AS | Construction | 2024 |
| Alexander Kiellandsgate 35 AS | Real estate | 2026 |
| Alexander Longum Olsen Holding AS | | 2022 |
| Alexiuz AS | Professional & scientific | 2017 |
| Alf Lie 1836 AS | Manufacturing | 2011 |
| Alf Lie Holding AS | Manufacturing | 2011 |
| Alf Solution AS | Professional & scientific | 2018 |
| Alfa Fasadevask Telemark AS | Administrative & support | 2022 |
| Alfie Bilskade AS | Other services | 2008 |
| Alfresco Invest AS | | 2020 |
| Alfsen Invest AS | Other services | 2023 |
| Alhs Holding AS | | 2010 |
| Ali Kilko Dagligvare AS | Wholesale & retail | 2026 |
| Alle Sanser AS | Wholesale & retail | 2018 |
| Alliert AS | Professional & scientific | 2020 |
| Alltid Betong AS | Manufacturing | 2021 |
| Almankaas AS | Wholesale & retail | 1994 |
| Almås Entreprenør AS | Construction | 2020 |
| Alook AS | Wholesale & retail | 2021 |
| Alpha Innovation Group AS | | 2022 |
| Alt Av Tjenester Ltd Nuf | Manufacturing | 2023 |
| Altech AS | Wholesale & retail | 2002 |
| Altenburg Holding AS | Construction | 2005 |
| Alti Tak Og Fasade AS | Construction | 2021 |
| Altimax AS | Construction | 2016 |
| Alula Naturformidling AS | Education | 2025 |
| Am Eiendom Skien AS | Real estate | 2003 |
| Am&Bf Invest AS | Real estate | 2021 |
| Am-Invest AS | | 2022 |
| Amedia Annonse Telemark Og Agder AS | Professional & scientific | 2022 |
| Amro Am Holding AS | Real estate | 2021 |
| Amro Invest AS | Financial services | 2005 |
| Amtmand Aallsgate 91 AS | Real estate | 2021 |
| Amtmann Meinichs Gate 15 Garasje AS | Real estate | 2020 |
| Amøbe Invest AS | | 2005 |
| Anastasia AS | Wholesale & retail | 2022 |
| Ances AS | Wholesale & retail | 2021 |
| Ancistrus AS | Professional & scientific | 2015 |
| Ancistrus Solutions AS | Professional & scientific | 2014 |
| Andelspartner AS | Professional & scientific | 2019 |
| Andengaard Invest AS | Wholesale & retail | 2019 |
| Anders Lia Holding AS | Financial services | 2014 |
| Andersen Kjell Kvaale & Co a | Wholesale & retail | 1995 |
| Andreas Billington Invest AS | Financial services | 2005 |
| Andreas Rønningen Holding AS | | 2020 |
| Anh Invest AS | | 2013 |
| Anita Thovsland Holding AS | Financial services | 2014 |
| Anja Larsen AS | Real estate | 2012 |
| Ank Genus Holding AS | | 2021 |
| Anka Holding AS | Wholesale & retail | 2024 |
| Ankast AS | Financial services | 2004 |
| Ann-Kristin's Beauty AS | Wholesale & retail | 2024 |
| Anna's Beauty Place AS | Other services | 2023 |
| Anona AS | Transport & logistics | 2021 |
| Anona Cargo AS | Transport & logistics | 2024 |
| Anona Group AS | Transport & logistics | 2023 |
| Ans Tonar Forretningsbygg | Real estate | 1987 |
| Antibes Invest AS | Financial services | 2005 |
| Antidot Helse AS | Health & social care | 2024 |
| Antikk Duestien AS | Wholesale & retail | 2022 |
| Antili AS | Information & communication | 2022 |
| Antin AS | Manufacturing | 2005 |
| Anton W Johansen AS | Manufacturing | 1982 |
| Aoø Holding Skien AS | Real estate | 2004 |
| Apiteq AS | Information & communication | 2005 |
| Aplia AS | Information & communication | 2012 |
| Apneseth Rådgivning AS | Professional & scientific | 2015 |
| Apper Systems AS | Information & communication | 2019 |
| Appify AS | Information & communication | 2019 |
| Applause Consulting AS | Information & communication | 2022 |
| Aprikos AS | Wholesale & retail | 2026 |
| Arai Eiendom AS | Real estate | 2015 |
| Arai Prosjekt AS | Real estate | 2010 |