| Kitkan Kämppä Avoin yhtiö | Real estate | 2004 |
| Koivulan Maito & Juusto Oy | Agriculture & fishing | 2021 |
| Kone-Justeeri Oy | Agriculture & fishing | 2013 |
| Konetekniikan Moniosaaja Oy | Professional & scientific | 2024 |
| Konetuote Pellinen Oy | Manufacturing | 1990 |
| Koneurakointi Haapala Ky | Construction | 2012 |
| Koneurakointi Hartikka Oy | Construction | 2006 |
| Koneurakointi M. Moilanen Oy | Construction | 2021 |
| Koneurakointi Maaninen Oy | Construction | 2019 |
| Koneurakointi Mustonen Ky | Construction | 1986 |
| Koneurakointi Nurro Oy | Construction | 2022 |
| Koskelta Oy | Professional & scientific | 2020 |
| Koveko Oy | Real estate | 2019 |
| Kryytimaa Oy | Real estate | 2019 |
| Kuljetus E ja T Posio | Transport & logistics | 2007 |
| Kuljetus Hepo-oja Oy | Transport & logistics | 1997 |
| Kärnän Pirtti Oy. | Hospitality | 1989 |
| LCR Action Oy | Hospitality | 2008 |
| LVI Vesiasennus Oy | Construction | 2019 |
| LaiffiGym Oy | Arts & recreation | 2010 |
| LarMar Oy | Hospitality | 1997 |
| Laserwood Oy | Manufacturing | 2018 |
| Lehtitek Oy | Construction | 2026 |
| Leipomo-konditoria Mimmin Pulla Oy | Wholesale & retail | 2008 |
| Louhi House Oy | Real estate | 2020 |
| Louhi60 Oy | Financial services | 2021 |
| Lunoa Solutions Oy | Information & communication | 2026 |
| Lux Adventure Finland Oy | Construction | 2022 |
| M & P Rimpeläinen Oy | Construction | 2006 |
| M & R Tikkanen Oy | Professional & scientific | 1986 |
| M&A Juvani Ky | Construction | 2011 |
| M&P Pikkarainen avoin yhtiö | Wholesale & retail | 2005 |
| MEP-Kiinteistöt Oy | Real estate | 2012 |
| Maanrakennus Aappo Laitinen Oy | Construction | 2004 |
| Maanrakennus Korkeakangas Oy | Construction | 2021 |
| Maanrakennus KuokkaJulle Ky | Construction | 2014 |
| Maansera Oy | Real estate | 1989 |
| Maansiirto P & J Vuoti Kommandiittiyhtiö | Construction | 1998 |
| Maansiirto Risto Komulainen Ky | Construction | 1986 |
| Maatalouskonehuolto Risto Uutinen Oy | Manufacturing | 1992 |
| MarMatin Maatila Oy | Agriculture & fishing | 2021 |
| MaxSHEQ OY | Construction | 2026 |
| Maxi-Mur Oy | Wholesale & retail | 2009 |
| Mertrei Oy | Wholesale & retail | 2026 |
| Metsätyö JMT Oy | Agriculture & fishing | 2022 |
| Metsätyö Siika-aho Oy | Agriculture & fishing | 2019 |
| Mill Hill Garage Oy | Professional & scientific | 2023 |
| Mivoco Ky | Wholesale & retail | 1987 |
| Montan Lohi Oy | Agriculture & fishing | 2009 |
| Mucon Oy | Mining & quarrying | 1989 |
| Muhoksen Airlus Ky | Construction | 1990 |
| Muhoksen Asunnot Oy | Real estate | 2025 |
| Muhoksen Atk-palvelu Ky | Information & communication | 1990 |
| Muhoksen Autogrilli Pikalounas Ky | Hospitality | 1989 |
| Muhoksen Autohuolto Ky | Other services | 1993 |
| Muhoksen Autoplussa Oy | Other services | 2023 |
| Muhoksen Bella Oy | Hospitality | 2023 |
| Muhoksen Biokuljetus Oy | Transport & logistics | 1997 |
| Muhoksen Energia Oy | Professional & scientific | 1980 |
| Muhoksen Jaha Oy | Real estate | 2012 |
| Muhoksen Kauppakeskus Oy | Construction | 1967 |
| Muhoksen Kukka ja Hautaustoimisto Kumpula Ky | Other services | 1982 |
| Muhoksen LVI-Palvelu Oy | Construction | 2007 |
| Muhoksen Mummola Oy | Hospitality | 2026 |
| Muhoksen Nurmikonepalvelu Oy | Agriculture & fishing | 2014 |
| Muhoksen Rantamattila Oy | Financial services | 1988 |
| Muhoksen Rauta Oy | Wholesale & retail | 1995 |
| Muhoksen Sähköosuuskunta | Energy | 1921 |
| Muhoksen Taksi Oy | Transport & logistics | 2009 |
| Muhoksen Tiilitie Oy | Real estate | 2021 |
| Muhoksen Varaosakeskus Oy | Wholesale & retail | 2023 |
| Muhoksen Vauriokorjaamo Oy | Other services | 2026 |
| Muhoksen Vesi- ja Maatyö Oy | Construction | 1985 |
| Muhoksen Vesihuolto Oy | Water & waste | 2003 |
| Muhoksen Välityspörssi Oy | Wholesale & retail | 2025 |
| Muhoksen traktorityö Ky | Mining & quarrying | 2006 |
| Muhoksenasema Oy | Hospitality | 2024 |
| Muhos Markkinointi Oy | Wholesale & retail | 1998 |
| Muutosmatka Osakeyhtiö | Administrative & support | 2022 |
| Nature Dream Days Oy | Hospitality | 2024 |
| Nemlog Oy | Agriculture & fishing | 2015 |
| NeoMaster Oy | Information & communication | 2010 |
| Neohot Oy | Construction | 2006 |
| Neopolar Oy | Manufacturing | 1994 |
| Niskan insinööripalvelut Oy | Professional & scientific | 2025 |
| Nordevice Oy | Information & communication | 2020 |
| Northern Lights Taiga OY | Administrative & support | 2025 |
| Northern One Oy | Health & social care | 1992 |
| Nova Antlia Oy | Water & waste | 2021 |
| Näläkäsen Herkku Oy | Wholesale & retail | 1995 |
| OJL-Talotekniikka Oy | Construction | 2016 |
| OV-Laatu Oy | Manufacturing | 1993 |
| Omtek Oy | Manufacturing | 1981 |
| One Staff Group OY | Construction | 2026 |
| Open 247 Oy | Administrative & support | 2019 |
| Osuuskunta Lumi Arancio | Professional & scientific | 2012 |
| Oulujoen Metsätyö Oy | Agriculture & fishing | 2021 |
| Oulujoen Palvelut Oy | Transport & logistics | 2007 |
| Oulujoen perhekoti Oy | Health & social care | 2000 |
| Oulujokilaakson Golf Oy | Arts & recreation | 2004 |