| Christinelund Barnehage AS | Education | 2025 |
| Ciping Holding AS | | 2020 |
| Citygroup Norway AS | Real estate | 2018 |
| Clifton Holding AS | Wholesale & retail | 2021 |
| Cloud Telecom AS | Wholesale & retail | 2015 |
| Complexsad Norway AS | Transport & logistics | 2016 |
| Compusoft AS | Information & communication | 1989 |
| Compusoft Norge AS | Information & communication | 1996 |
| Conductor AS | Construction | 2007 |
| Continental-Invest AS | Financial services | 1989 |
| Crazed AS | Wholesale & retail | 2026 |
| Da-Jo Eiendom AS | Real estate | 2023 |
| Dahl Multiservice AS | Professional & scientific | 2015 |
| Danatoys AS | Wholesale & retail | 2023 |
| DBS Eiendom AS | Real estate | 2015 |
| DBS Holding AS | Other services | 2005 |
| Deilig Bite AS | Hospitality | 2025 |
| Derbigum Norge AS | Wholesale & retail | 1982 |
| Derbitak Østfold AS | Construction | 2024 |
| Detensio AS | Wholesale & retail | 2010 |
| Digihuset AS | Wholesale & retail | 2018 |
| Din Bilservice AS | Other services | 2015 |
| Din-Eiendom AS | Real estate | 2021 |
| Directa AS | Professional & scientific | 2008 |
| Dogshop AS | Wholesale & retail | 2020 |
| Dominus Argentum AS | Wholesale & retail | 2024 |
| Due Hafslund AS | Wholesale & retail | 2016 |
| E&E Company AS | Construction | 2014 |
| Ecoride AS | Wholesale & retail | 2010 |
| Eikelund Vann Og Avløp SA | Water & waste | 2023 |
| Einherjar Corp Nuf | Construction | 2025 |
| Eive AS | Administrative & support | 2019 |
| El-Scootern AS | Wholesale & retail | 2018 |
| Elsan AS | Construction | 2026 |
| Emgods AS | Manufacturing | 2009 |
| Emilsen Reklamebyrå AS | Professional & scientific | 1987 |
| Energyautomation AS | Professional & scientific | 2018 |
| Enøk Systemer Holding AS | Construction | 2006 |
| Enøk-Systemer AS | Construction | 2017 |
| Epicom Invest AS | | 2002 |
| Er.A Holding AS | | 2022 |
| Erel-Nor AS | Administrative & support | 2013 |
| Everksveien 1 AS | | 2026 |
| F&L Holding AS | | 2023 |
| Fagdekk Sarpsborg AS | Wholesale & retail | 2021 |
| Fairplay AS | Real estate | 2020 |
| Fam Engebretsen Holding AS | | 2026 |
| Familieveiledningen AS | Health & social care | 2012 |
| Filfri Holding AS | | 2023 |
| FJ Consulting AS | Professional & scientific | 2015 |
| Fjelldal Barnehage AS | Education | 2007 |
| Fjærvik Holding AS | | 2022 |
| Folkvang AS | Professional & scientific | 2016 |
| Folkvang Økonomi AS | Professional & scientific | 2018 |
| Forsell Make the Difference AS | Arts & recreation | 2021 |
| Fortius Invest AS | Real estate | 2004 |
| Framsport AS | Wholesale & retail | 2019 |
| Fredriksstad Motorfabrik AS | Manufacturing | 1923 |
| Fredrikstad Asfalt AS | Construction | 2014 |
| Freidig Bygg AS | Construction | 2026 |
| Frigoglass Nordic AS | Wholesale & retail | 2003 |
| Friske Føtter Terapi Og Velvære AS | Other services | 2021 |
| Fryd Event Da | Administrative & support | 2017 |
| Frydenbø Boats AS | Manufacturing | 1990 |
| Frydenbø Marine AS | Wholesale & retail | 2020 |
| Fukt Og Lekkasje Teknikk AS | Construction | 2018 |
| Gave & Interiør Agenturet AS | Real estate | 2005 |
| Globe Energy Charge AS | Wholesale & retail | 2026 |
| Globe Energy Norway AS | Professional & scientific | 2024 |
| Gme Eiendom AS | Real estate | 2017 |
| GR Capital AS | | 2025 |
| GR Eiendom AS | Real estate | 2025 |
| GR Renovasjon AS | Water & waste | 2022 |
| Great Vacation AS | Administrative & support | 2024 |
| Gretland Reno AS | Water & waste | 2019 |
| Grønberg AS | Wholesale & retail | 2012 |
| Gsi Norway AS | Wholesale & retail | 2009 |
| Gundersen & Co AS | Construction | 2020 |
| Gundersen Da | Wholesale & retail | 1999 |
| Gvito Records and Publishing Da | Information & communication | 2016 |
| H. Klausen Holding AS | | 2024 |
| Ha-Ta Holding AS | Financial services | 2012 |
| Hafsil AS | Manufacturing | 2005 |
| Hafslund Bilservice AS | Other services | 2019 |
| Hafslund Dekksenter AS | Wholesale & retail | 2018 |
| Hamang Trafikkskole AS | Education | 2012 |
| Hamang Trafikkskole Avd. Peter AS | Education | 2023 |
| Hamang Trafikkskole Avd. Svend AS | Education | 2018 |
| Happyprice Da | Wholesale & retail | 2008 |
| Harald Holding AS | Financial services | 2005 |
| Harlem Kjøtt AS | Manufacturing | 1997 |
| Harlem Rør AS | Construction | 2025 |
| Havneberget Utvikling AS | Real estate | 2021 |
| Hawa AS | | 2007 |
| HB Kuldetjeneste AS | Construction | 2010 |
| Hb-Service AS | Professional & scientific | 2023 |
| Helsand Holding AS | | 2025 |
| Helsearena AS | Other services | 2018 |
| Henning Skrøder Fiske Og Service AS | Agriculture & fishing | 2024 |
| Herceglija Holding AS | | 2026 |