| Autoretur Battery Recycling AS | Oslo | 2025 |
| Autoreturn AS | Oslo | 2014 |
| Autoringen AS | Skedsmokorset | 2004 |
| Autosale Utleie AS | Kokstad | 2023 |
| Autostore Technology AS | Nedre Vats | 1998 |
| Autostrada Bilutleie AS | Porsgrunn | 2018 |
| Autosync AS | Oslo | 2019 |
| Autoteam Bilutleie AS | Sandnes | 1986 |
| Autozentrum Bilutleie AS | Oslo | 2020 |
| Auwi AS | Dale I Sunnfjord | 2004 |
| Auxilia AS | Tromsø | 2019 |
| Av Bidco AS | Oslo | 2022 |
| Av Service AS | Flekkefjord | 2017 |
| Av-Konsept AS | Oslo | 2006 |
| Avail AS | Drammen | 2024 |
| Avanci International Limited | Ie-Carrickmines D18 Ax61 | 2022 |
| Avant Event AS | Oslo | 2011 |
| Avantas Drift AS | Trondheim | 2001 |
| Avantic Norge AS | Laksevåg | 2003 |
| Avarn Security AS | Oslo | 1987 |
| Avarn Security Aviation AS | Gardermoen | 2008 |
| Avarn Security Beredskap AS | Porsgrunn | 2005 |
| Avarn Security Group AS | Oslo | 2021 |
| Avarn Security Group Holding AS | Oslo | 2021 |
| Avarn Security Group Invest AS | Oslo | 2021 |
| Avarn Security Holding AS | Oslo | 2015 |
| Avarn Security Service AS | Tønsberg | 2013 |
| Avatar AS | Vardø | 1997 |
| Avea Gruppen AS | Vøyenenga | 2023 |
| Avec Trade SK S.R.O | Sk-01001 Zilina | 2013 |
| Aventi Solutions Norge AS | Oslo | 2019 |
| Aveny Holding AS | Søreidgrend | 2015 |
| Avepoint Deutschland GmbH | 80335 München | 2015 |
| Aveva Do Brasil Information Ltda | Rio De Janeiro | 2015 |
| Avfallssekk AS | Ås | 2022 |
| Avia Transport Systems AS | Ålesund | 2000 |
| Aviation Capital AS | Oslo | 2021 |
| Avicenna Cura AS | Lørenskog | 2022 |
| Aviga AS | Fjellhamar | 2022 |
| Avigo Kommunale Tjenester AS | Lillesand | 2020 |
| Avimar Eiendom AS | Oslo | 1999 |
| Avincis Aviation Fleet Management Nordics AS | Tromsø | 2011 |
| Avionis AS | Laksevåg | 2024 |
| Avirent AS | Haugesund | 2018 |
| Avis Budget UK Limited | Bracknell Rg12 2Ev | 2019 |
| Avløysaren AS | Sandnes | 2013 |
| Avn Holding AS | Rygge | 2023 |
| Avni AS | Oslo | 2024 |
| Avon Live Oslo AS | Oslo | 2017 |
| Avp Utleie AS | Straume | 2019 |
| Avra Utleie AS | Skedsmokorset | 2024 |
| Avseth Aktiv AS | Giske | 2011 |
| Avseth AS | Giske | 2006 |
| Avsm AS | Oslo | 2023 |
| Avvr AS | Jessheim | 2025 |
| Avyro Fleet AS | Oslo | 2026 |
| Aw Maskin AS | Overhalla | 2015 |
| Awayzing Travel AS | Sola | 2022 |
| Awaze AS | Mesnali | 1982 |
| Awbound AS | Rådal | 2025 |
| Aweco Services AS | Oslo | 2025 |
| Ax Salgstjenester AS | Haltdalen | 2018 |
| Axactor ASA | Oslo | 1982 |
| Axactor Norway AS | Drammen | 2013 |
| Axactor Sweden AB | Se-411 05 Göteborg | 2024 |
| Axels Group AB | Se-300 07 Halmstad | 2021 |
| Axels Tivoli AB Nuf | Se-302 53 Halmstad | 2025 |
| Axera AS | Oslo | 2018 |
| Axfr 08 Ltd Nuf | N146Qh, London, Southgate | 2007 |
| Aximed AS | Bergen | 1998 |
| Axios Norway AS | Sandnes | 2024 |
| Axios Recursos Humanos, SL | Es-28100 Alcobendas-Madrid | 2024 |
| Axis Solutions AS | Kløfta | 2024 |
| Axora AS | Gamle Fredrikstad | 2025 |
| Axura Bygg Tjenester AS | Hundvåg | 2025 |
| Axxis Geo Solutions Inc | Houston Tx 777079 | 2019 |
| Aya AS | Oslo | 2022 |
| Ayme Renhold AS | Ytre Enebakk | 2022 |
| Ayudia AS | Spikkestad | 2021 |
| Ayvens Norge AS | Oslo | 1987 |
| Azane Infrastructure AS | Oslo | 2025 |
| Azouagh Invest AS | Oslo | 2024 |
| Anticimex A/S | Oslo | 1973 |
| Avisretur A/S | Oslo | 1988 |
| Aå Service AS | Ålesund | 2023 |
| Aåb Bjørklund Holding AS | Alta | 2011 |
| B & G Welding Contracting AS | Rennesøy | 2014 |
| B & K Holding AS | Lørenskog | 2018 |
| B & K Vask Da | Kristiansand S | 1988 |
| B & M Management AS | Oslo | 1991 |
| B 7 Kontorsenter AS | Oslo | 2009 |
| B K Holding AS | Spillum | 2019 |
| B K Utleie AS | Spillum | 2022 |
| B Management AS | Kristiansund N | 2019 |
| B Oust AS | Trondheim | 2013 |
| B Pedersen Invest AS | Revetal | 2014 |
| B&B Scandinavia AS | Oslo | 2025 |
| B&B Stillasutleie Grenland AS | Skien | 2020 |
| B&Bbl Kulturkonsulenter Ans | Oslo | 2005 |
| B&G Braaten Og Granberg | Ål | 2018 |