| Kongsvinger Sjukehus Utvikling AS | | 2001 |
| Kongsvinger Spa AS | Health & social care | 2003 |
| Kongsvinger Sport & Fritid AS | Wholesale & retail | 2002 |
| Kongsvinger Tannregulering AS | Health & social care | 2014 |
| Kongsvinger Tomteutvikling AS | Real estate | 2021 |
| Kongsvinger Transport AS | Transport & logistics | 2015 |
| Kongsvinger Transportbyrå AS | Transport & logistics | 1997 |
| Kongsvinger Trening AS | Arts & recreation | 2019 |
| Kongsvinger Treningssenter AS | Arts & recreation | 2020 |
| Kongsvinger Ur Og Smykker AS | Wholesale & retail | 2000 |
| Kongsvinger Øre Nese Hals AS | Health & social care | 2022 |
| Konkav Atelier AS | Other services | 2024 |
| Koppom Maskin AS | Wholesale & retail | 2021 |
| Kos Utvikling AS | Construction | 2022 |
| Krabseth Holding AS | Financial services | 2005 |
| Kremmerhuset Kværne Ans | Wholesale & retail | 1989 |
| Kremtomta AS | Real estate | 2008 |
| Kristiansen Bilberging Og Bilutleie AS | Transport & logistics | 2011 |
| Kulturformidling Romfolket AS | Health & social care | 2019 |
| Kurer Grafisk AS | Professional & scientific | 1999 |
| Kurer Holding AS | Real estate | 1999 |
| Kurer Logistikk AS | Transport & logistics | 2011 |
| Kurudsand Eiendom AS | Real estate | 2023 |
| Kurér AS | Transport & logistics | 2001 |
| Kvale 1 AS | Real estate | 2008 |
| Kvale AS | Real estate | 2005 |
| Kvernbakken Invest AS | Wholesale & retail | 2022 |
| Kvikk Fuel AS | Wholesale & retail | 2017 |
| Kyla & Varmesupport FS AB | Construction | 2008 |
| Lars Henrik Sutterud AS | Real estate | 2013 |
| Larseninvest AS | Professional & scientific | 2019 |
| Laxov AS | Real estate | 2021 |
| Lca Invest AS | | 2025 |
| Lefrem Invest AS | | 2019 |
| Lia Barnehage SA | Education | 1989 |
| Liaveien 22 AS | Real estate | 2008 |
| Lillebekk Invest AS | Real estate | 2018 |
| Lillepus Publishing AS | Information & communication | 2023 |
| Linda Østlie AS | Education | 2018 |
| Locomotion Ans | Information & communication | 2014 |
| Lokalbakern AS | Wholesale & retail | 2023 |
| Lrdeiendom AS | Real estate | 2020 |
| Lumo Maskin Og Eiendom AS | Real estate | 2021 |
| Luxfurnia Da | Wholesale & retail | 2020 |
| LVV AS | Administrative & support | 2024 |
| Lypark Eiendom Da | Real estate | 2006 |
| Lustra Skogsdrift ANS | | 1988 |
| Mads Nordnes AS | Real estate | 2015 |
| Maelti AS | Administrative & support | 2025 |
| Maistro AS | Hospitality | 2023 |
| Malermester Ljungquist AS | Construction | 2019 |
| Mamamum AS | Wholesale & retail | 2026 |
| Manis AS | Hospitality | 2011 |
| Mantra MMM AS | Professional & scientific | 2026 |
| Mara Marketing | Information & communication | 2014 |
| Mari Rimfeldt AS | Financial services | 2005 |
| Marias Klinikk AS | Other services | 2013 |
| Markensplassen AS | Real estate | 2007 |
| Marnstuen Media AS | Information & communication | 1998 |
| Masonmale AS | Wholesale & retail | 2025 |
| Masse Gjenbruks Senteret AS | Manufacturing | 1994 |
| Mbe Renovering AS | Construction | 2016 |
| Mcmartha´S Collections AS | Manufacturing | 2026 |
| Mecc Holding AS | Professional & scientific | 2022 |
| Mesnadalsvegen 2 AS | Real estate | 2021 |
| Mestringsbo AS | Real estate | 2016 |
| Metacon Stålbygg AS | Construction | 2015 |
| MG Regnskap AS | Professional & scientific | 2021 |
| MGD AS | Hospitality | 2022 |
| MH Service Da | Manufacturing | 2021 |
| Mibo Klinikken AS | Health & social care | 2020 |
| Midcon AS | Wholesale & retail | 2011 |
| Midcon Eiendom AS | Real estate | 2025 |
| Midtbyen Legesenter Kongsvinger Da | Health & social care | 2009 |
| Migge Invest AS | | 2007 |
| Minkhes AS | Construction | 2024 |
| Mittkongsvinger.No AS | Information & communication | 2020 |
| MJG Medical AS | Health & social care | 2023 |
| MJJ Invest AS | Real estate | 2010 |
| Mjøsa Betong AS | Manufacturing | 2010 |
| MM Invest AS | Real estate | 2014 |
| MN Drift AS | Health & social care | 2023 |
| Mobile Kongsvinger AS | Other services | 2015 |
| Moelv Verktøy AS | Manufacturing | 2023 |
| Moens Mat Og Drikke AS | Hospitality | 2025 |
| Mokita AS | Health & social care | 2021 |
| Monette Frisør AS | Other services | 2016 |
| Mosquito Film AS | Information & communication | 2024 |
| Motorsykkelsiden AS | Information & communication | 2023 |
| Mstyle Frisør AS | Other services | 2021 |
| Multiflora Eiendom AS | Real estate | 2000 |
| Mursenteret Glåmdal AS | | 2001 |
| Mårvegen 2 AS | Real estate | 2015 |
| Mårvegen 30 AS | Real estate | 2026 |
| Mårvegen 32 AS | Real estate | 2026 |
| Mårvegen 7 AS | Administrative & support | 2026 |
| Mårvegen AS | Real estate | 2020 |
| Mårveien Eiendom AS | Real estate | 2002 |
| Møbelringen Kongsvinger AS | Wholesale & retail | 1993 |
| Na Handel AS | Wholesale & retail | 2018 |