| 2 Malere AS | Construction | 2020 |
| Ada&Vilde AS | Professional & scientific | 2014 |
| Adco Invest AS | Hospitality | 2018 |
| AI Innovate AS | Information & communication | 2025 |
| AI Innovate Holding AS | Wholesale & retail | 2025 |
| Aim Customs Partner AS | Transport & logistics | 2026 |
| Amundsens Pilkstøperi Ans | Manufacturing | 1997 |
| Atlas Media AS | Information & communication | 2019 |
| Babylons Pizza AS | Hospitality | 2014 |
| Bagorama AS | Wholesale & retail | 2005 |
| Bagorama Nettbutikk AS | Wholesale & retail | 2018 |
| Bagorama Oslo City AS | Wholesale & retail | 1990 |
| Bagorama Regnskap AS | Professional & scientific | 2019 |
| Bakken Auto AS | Other services | 1986 |
| Bakst AS | Manufacturing | 2024 |
| BEE2BEE AS | Administrative & support | 2013 |
| BEE2BEE Oslo Og Akershus AS | Administrative & support | 2013 |
| Befro Holding AS | Real estate | 2012 |
| Betulae AS | Information & communication | 2018 |
| Bjørnstad Transport AS | Transport & logistics | 2012 |
| Bke Eiendom AS | Real estate | 2012 |
| Bo's Flissalg AS | Wholesale & retail | 2008 |
| Bollerød Fus Barnehage AS | Education | 2018 |
| Borg Arkitektur AS | Professional & scientific | 2014 |
| Brygg Og Bakst AS | Hospitality | 2024 |
| Brødrene Fuglevig Da | Construction | 2020 |
| Brødrene Madsen Kran & Transport AS | Transport & logistics | 2023 |
| BT Plast Halden AS | Manufacturing | 1991 |
| Btplast Eiendom AS | Manufacturing | 2007 |
| Btplast Holding AS | Manufacturing | 2013 |
| BYGG24 Tjenester AS | Construction | 2024 |
| Byggefirma Gjødalstuen Og Moen Da | Construction | 2002 |
| Byggmester Eriksen AS | Construction | 2012 |
| Byggmester Patrick Isaksen AS | Construction | 2018 |
| Byk Auto AS | Wholesale & retail | 2026 |
| Båtbygger Tormod Johannessen AS | Manufacturing | 2015 |
| Cathrine Trønnes Lie AS | Health & social care | 2023 |
| Celas AS | Other services | 2025 |
| Chillout Holding AS | Wholesale & retail | 2015 |
| CHS Invest AS | Wholesale & retail | 2021 |
| Ciroko Norge Nuf | Construction | 2007 |
| Cowberry AS | Administrative & support | 2014 |
| Cremedia AS | Information & communication | 2012 |
| CTL Flis & Bygg AS | Construction | 2018 |
| Cum-Cura AS | Education | 2011 |
| D Amour AS | Other services | 2024 |
| Dahlman Holding AS | Real estate | 2022 |
| Damstredet 6 Og 6 a AS | Real estate | 2021 |
| Eggum Investering AS | | 2026 |
| Endresen Eiendomsutleie AS | Real estate | 2021 |
| Erbe AS | Real estate | 2004 |
| Erikbo AS | Health & social care | 2011 |
| Ernex AS | Manufacturing | 1984 |
| Evla AS | | 2023 |
| Evlon AS | Wholesale & retail | 2026 |
| Erling Grimsrud AS | Construction | 1982 |
| Fellesveien Femsjøen-Holvannet- Bjørnetjern SA | Agriculture & fishing | 1955 |
| Filippa Sushi AS | Hospitality | 2014 |
| Fjordkompaniet AS | Professional & scientific | 2018 |
| Flatebyveien 1 AS | Real estate | 1995 |
| Fosseveien Atelierfellesskap AS | Real estate | 2002 |
| Framviks Import Da | Wholesale & retail | 2004 |
| Fredrikshald Multitjenester AS | Manufacturing | 2023 |
| FWC Holding AS | | 2026 |
| GB Maskin Halden AS | Construction | 2017 |
| GCL Invest AS | Financial services | 2005 |
| GDX AS | Wholesale & retail | 2013 |
| GR Invest AS | Financial services | 2005 |
| Granveien 2 AS | Real estate | 2014 |
| Greenplanet AS | Administrative & support | 2020 |
| Grim Entertainment AS | Professional & scientific | 1984 |
| Grimsrud Utvikling AS | Construction | 2005 |
| Grimsrødhøgda 50 AS | Real estate | 2016 |
| Grinda Bildeler AS | Wholesale & retail | 2013 |
| Grotten På Torvet AS | Hospitality | 2023 |
| Grønberg Holding AS | Financial services | 2014 |
| GT Gruppen AS | Real estate | 2021 |
| H Eiendom Og Invest AS | Real estate | 2022 |
| Halden Bookworks AS | Real estate | 2020 |
| Halden Bruktbildeler Ans | Wholesale & retail | 1988 |
| Halden Eiendomsutvikling AS | Real estate | 2002 |
| Halden Elektronikk AS | Manufacturing | 1986 |
| Halden Roulettdrift Da | Arts & recreation | 1993 |
| Halden Tredesign AS | Manufacturing | 2022 |
| Halden Tømrerfirma AS | Construction | 2014 |
| Hamek AS | Professional & scientific | 2003 |
| Hamek Kompetansesenter AS | Professional & scientific | 2016 |
| Heavy Metal Nightmare Da | Information & communication | 2009 |
| Holly Jhones AS | Real estate | 2012 |
| HRD Casino Drift Da | Arts & recreation | 2001 |
| Huldra Rekvisitter AS | Other services | 2023 |
| Huntrekruttering AS | Professional & scientific | 2021 |
| Halden ServiceSenter ANS | Other services | 1988 |
| Høstbakken Eiendom AS | Real estate | 2007 |
| Høstbakken Eiendomsservice AS | Administrative & support | 2016 |
| Indoro Transport AS | Transport & logistics | 2019 |
| Industritjenesten AS | Professional & scientific | 2017 |
| Infinite Holding AS | Wholesale & retail | 2020 |
| Ingeniør Nerby AS | Professional & scientific | 2014 |
| Ingeniørgleder AS | Construction | 2018 |