| Elem Utleie AS | Wholesale & retail | 2019 |
| Eliassen Bygg AS | Construction | 2011 |
| Elisabeth Storvoll AS | | 2023 |
| Emanuelle Parfymeri AS | Wholesale & retail | 1992 |
| Empakk AS | Wholesale & retail | 2002 |
| Encanto Second Hand AS | Wholesale & retail | 2022 |
| Energismart Norge AS | Professional & scientific | 2010 |
| Enter Solution AS | Professional & scientific | 2023 |
| EURO44 AS | Wholesale & retail | 2019 |
| Europris AS | Wholesale & retail | 2004 |
| Europris ASA | Wholesale & retail | 2011 |
| Europris Butikkdrift AS | Wholesale & retail | 2004 |
| Europris Holding AS | Wholesale & retail | 2011 |
| Eva Nordic AS | Information & communication | 2023 |
| Exit-Invest AS | | 2021 |
| Exposure North AS | Professional & scientific | 2026 |
| Express-Service AS | Other services | 2015 |
| Face Academy AS | Education | 2023 |
| Farmateket AS | Manufacturing | 1999 |
| Ferej Holding AS | Hospitality | 2021 |
| Fibel AS | Wholesale & retail | 2026 |
| Finestra AS | Wholesale & retail | 2017 |
| Flexonor Ans | Professional & scientific | 1997 |
| Folkets Regnskap AS | Professional & scientific | 2025 |
| Frebra Holding AS | Professional & scientific | 2015 |
| Fredrikstad Invest AS | Administrative & support | 2004 |
| Fredrikstad Rørleggerservice AS | Construction | 2008 |
| Fredrikstad Storhusholdning AS | Wholesale & retail | 2011 |
| Fredrikstad Storkjøkkensenter AS | Wholesale & retail | 2024 |
| Fredrikstad Tannhelse AS | Health & social care | 2016 |
| Fredrikstad Øre-Nese-Hals AS | Health & social care | 2025 |
| G.H. Engineering AS | Professional & scientific | 2014 |
| Ga Utleie AS | Administrative & support | 2008 |
| Galleri 1845 AS | Wholesale & retail | 2020 |
| Gastro Storkjøkken AS | Wholesale & retail | 2013 |
| GHM Holding AS | Real estate | 2016 |
| Glede AS | Wholesale & retail | 2021 |
| Glemmen Gård Utvikling AS | Real estate | 2012 |
| Glomma Drift AS | Arts & recreation | 1997 |
| Glomma Eiendom AS | Real estate | 2011 |
| Glomma Yrkesklær AS | Wholesale & retail | 2019 |
| Golding Gruppen AS | Wholesale & retail | 2018 |
| Golding Holding AS | Construction | 2006 |
| Gorges AS | | 2019 |
| Granlien Og Diedrichsen Konsult AS | Information & communication | 2012 |
| Grini AS | Real estate | 2006 |
| Grønn Jobb AS | Health & social care | 2010 |
| Grønn Jobb Holding AS | Health & social care | 2009 |
| Grønne Investeringer AS | Construction | 2004 |
| Grøntbud.No AS | Transport & logistics | 2018 |
| Gullpakka AS | Manufacturing | 2018 |
| Gym 4 You AS | Arts & recreation | 2005 |
| Gård- Og Hageservice Da | Administrative & support | 2011 |
| Hag Kvalitetsmøbler AS | Wholesale & retail | 1994 |
| Hallgren Kostveit AS | Professional & scientific | 2012 |
| Halo Aktiva AS | Real estate | 2021 |
| Halo Property AS | Real estate | 2016 |
| Hamre Elektronikk AS | Manufacturing | 2013 |
| Hansen Motor AS | Other services | 2020 |
| Hansen Og Eriksen Holding AS | Manufacturing | 2008 |
| Hansen Sveis & Montering AS | Manufacturing | 1997 |
| Harmoni Frisør AS | Other services | 2011 |
| Harmony Drive Da | Arts & recreation | 2017 |
| Hartmand Da | Wholesale & retail | 2017 |
| Haugeløkka Barnehage AS | Education | 2022 |
| Haugesten Gruppen AS | | 2026 |
| Haugetun Catering AS | Hospitality | 1994 |
| Haugrim AS | | 2020 |
| HC Rolvsøy AS | Other services | 2014 |
| Helse Og Friskvern AS | Health & social care | 2020 |
| Hjem Og Hytte AS | Wholesale & retail | 2013 |
| HK Salong AS | Health & social care | 2018 |
| Holm-Eiendom AS | Real estate | 2024 |
| Holmskau Eiendom AS | Real estate | 2006 |
| Holmskau Prosjekt AS | Real estate | 2007 |
| Holmskog Holding AS | Construction | 2005 |
| HTH Kjøkken Østfold AS | Wholesale & retail | 2015 |
| Hundetygg AS | Wholesale & retail | 2022 |
| Husdalen Eiendom Da | Real estate | 2008 |
| Hvaler Bruktbil AS | Wholesale & retail | 2023 |
| I Revisjon Og Regnskap AS | Professional & scientific | 2025 |
| Ifratelli Eiendom AS | Real estate | 2014 |
| Ilj Holding AS | Financial services | 2013 |
| Imte Eiendom AS | Real estate | 2016 |
| Infocus International BV | Professional & scientific | 2009 |
| Ingeniørfirma Big AS | Professional & scientific | 1996 |
| Inlet AS | Information & communication | 2020 |
| Inmotec AS | Professional & scientific | 2025 |
| Inspirasjon Forlag AS | Wholesale & retail | 1977 |
| Installatøren Fredrikstad AS | Construction | 2013 |
| Invasion Music Da | Arts & recreation | 2026 |
| Invest-Auto AS | Wholesale & retail | 1996 |
| Iversby Eiendom AS | Real estate | 1999 |
| Iversby Holding AS | | 2021 |
| Je Holding AS | Wholesale & retail | 2003 |
| JLJ Holding AS | | 2021 |
| Jobo Eiendom AS | | 2026 |
| Jobo Utleie AS | Real estate | 2026 |
| Johansen Energi AS | Construction | 2013 |
| John Johansen Holding AS | | 2005 |