| 7BEANSTALK AS | Wholesale & retail | 2023 |
| A-Å Regnskap AS | Professional & scientific | 2017 |
| A.W. Faber-Castell Nordic Aps | Professional & scientific | 2012 |
| Aabysætra AS | Real estate | 2005 |
| Aaron Weggersen Consulting AS | Information & communication | 2025 |
| Abk-Holding AS | Real estate | 2019 |
| Abnc AS | Wholesale & retail | 2018 |
| Accord Holding AS | Wholesale & retail | 2024 |
| Accord Industries AS | Wholesale & retail | 2024 |
| Accourat Lager Og Hagearbeider AS | Other services | 2020 |
| Accourat Vaktmester & Hageservice Nuf | Administrative & support | 2016 |
| Affabel AS | Health & social care | 2023 |
| Air Liquide Norway AS | Wholesale & retail | 1997 |
| Aj Maskinutleie AS | Administrative & support | 2017 |
| Aj Økonomi Og Regnskap AS | Professional & scientific | 2014 |
| Akrobat AS | Professional & scientific | 2016 |
| Aktiv Eiker Og Modum AS | Real estate | 2019 |
| Alfa Brannvern AS | Wholesale & retail | 2006 |
| Alfheim Eiendom AS | Real estate | 2011 |
| Alog AS | Transport & logistics | 2022 |
| Altservice Norge AS | Construction | 2025 |
| Amk Holding AS | Financial services | 2005 |
| Amnity AS | Arts & recreation | 2024 |
| Anel Jakupovic AS | Water & waste | 2026 |
| Anem Invest AS | Financial services | 2006 |
| ANS MAY-B OMDAHL & Co | | 1987 |
| Anton Engensvei 1 Ans | Real estate | 2000 |
| Apollo Budbiler AS | Transport & logistics | 2010 |
| Aporta Games AS | Information & communication | 2014 |
| Apperio AS | Information & communication | 2023 |
| Arbeidergata Invest AS | Real estate | 2013 |
| Arbeidergaten 28 AS | Real estate | 2012 |
| Ari Technology AS | Information & communication | 2023 |
| Arita Brands AS | Professional & scientific | 2023 |
| Arkhi AS | Real estate | 2017 |
| Arnesen Bygg Ans | Construction | 1989 |
| Arro Bygg Og Drift AS | Real estate | 2016 |
| Arro Eiendom AS | Real estate | 2009 |
| Arro Holding AS | Real estate | 2005 |
| Artisthuset AS | Information & communication | 2014 |
| AS Mjøndalen Installasjon | Construction | 1967 |
| Askland AS | Wholesale & retail | 1988 |
| Assis AS | Real estate | 2023 |
| At Transport AS | Transport & logistics | 1980 |
| Ateo Bygg AS | Manufacturing | 2024 |
| Audatobygg AS | Construction | 2025 |
| Auto Connect AS | Wholesale & retail | 2018 |
| Autocars AS | Wholesale & retail | 2024 |
| Autoklar AS | Other services | 2025 |
| Axsellerate AS | Education | 2017 |
| B.A Holding AS | | 2020 |
| Badena Butikkdrift AS | Wholesale & retail | 2022 |
| Bakeriinvest AS | Real estate | 1990 |
| Bakkefaret Fus Barnehage AS | Education | 2018 |
| Baklid Invest AS | | 2019 |
| Bastas Drift AS | Wholesale & retail | 2021 |
| Becher Holding AS | | 2024 |
| Been Holding AS | Transport & logistics | 2017 |
| Bekkestua Vest Bolig AS | Real estate | 2012 |
| Benjaminsen Takst AS | Real estate | 2025 |
| Bernth Holding AS | | 2021 |
| Better Web AS | Professional & scientific | 2020 |
| Beve Renhold Da | Administrative & support | 2023 |
| Bilstudio AS | Wholesale & retail | 2025 |
| Bingo Drammen AS | Arts & recreation | 2024 |
| Bio Viking AS | Wholesale & retail | 2010 |
| Birkeland Invest AS | Real estate | 2015 |
| Bjarre E Fevang AS | Real estate | 2005 |
| Bjarre E. Fevang Invest AS | Financial services | 2022 |
| Bjerkeengen Holding AS | Other services | 2025 |
| Blekkspruten Buskerud AS | Arts & recreation | 2005 |
| Bmtakst AS | Real estate | 2023 |
| Bo Bra Bygg Da | Construction | 1999 |
| Bobil Verden AS | Wholesale & retail | 2025 |
| Borgersen AS | Real estate | 2010 |
| Borgersen Transport AS | Transport & logistics | 2010 |
| BP Sport AS | Wholesale & retail | 2021 |
| Brani Asfalt AS | Construction | 2016 |
| Bre Mek AS | Manufacturing | 1993 |
| Brede Borgersen Holding AS | | 2023 |
| Bretvik Holding AS | Real estate | 2010 |
| BRS Auto AS | Wholesale & retail | 2013 |
| BT Bil & Fritid AS | Wholesale & retail | 2015 |
| Bubi AS | Wholesale & retail | 2023 |
| Budalstølen AS | Real estate | 2019 |
| Buin Holding AS | | 2024 |
| Buskerud Blomster AS | Wholesale & retail | 2017 |
| Buskerud Brukt & Invest AS | Wholesale & retail | 2014 |
| Buskerud Invest AS | Real estate | 2013 |
| Buskerud Miljøservice AS | Transport & logistics | 2023 |
| Buskerud Miljøservice Eiendom AS | Real estate | 2019 |
| Buskerud Miljøservice Holding AS | Real estate | 2023 |
| Buskerud Sprenging Og Graving AS | Construction | 2008 |
| Buskerud Tak Og Blikk AS | Construction | 2021 |
| Butikk Bastas AS | Wholesale & retail | 2022 |
| Buysec AS | Wholesale & retail | 1994 |
| Buytec AS | Wholesale & retail | 2005 |
| Bygg Mur Ekspert Ans | Construction | 2025 |
| Bøndernes Hus Mjøndalen AS | Real estate | 2013 |
| C&C Etterarbeid AS | Construction | 2023 |