| Likeline Oy | Transport & logistics | 1991 |
| Linnoituksen Voima Oy | Energy | 1994 |
| Linnoituksen terveys Oy | Real estate | 2023 |
| Livamylly Oy | Hospitality | 2020 |
| Lofeg Oy | Transport & logistics | 2021 |
| LogHouseDreams Oy | Arts & recreation | 2025 |
| Loma-Harvaja Oy | Hospitality | 2008 |
| Lumestetic Oy | Wholesale & retail | 2025 |
| Luumäen Yritystila Oy | Real estate | 1995 |
| Luvona Oy | Real estate | 2020 |
| Lämpö Oy Suntionkallio | Energy | 1985 |
| M&T Beauty Studio Oy | Wholesale & retail | 2021 |
| M-Invest Oy | Real estate | 1997 |
| Maanrakennus Mikko OY | Construction | 2009 |
| MAK Trading Oy Ltd | Transport & logistics | 2007 |
| MDFA GROUP Oy | Transport & logistics | 2013 |
| MJ-Pellitys Oy | Construction | 2021 |
| ML Pojat Oy | Construction | 2014 |
| MV Tili Ky | Professional & scientific | 2023 |
| Maanrakennus Mäkinen Oy | Real estate | 2023 |
| Maanrakennus Suortti Oy | Construction | 1959 |
| MaisemaTek Oy | Administrative & support | 2020 |
| Majoitus Toivanen Oy | Hospitality | 2024 |
| Majoituspalvelut Peltola Oy | Hospitality | 2024 |
| Manttari Holding Oy | Financial services | 2026 |
| Marjan Kenkä Ky | Wholesale & retail | 1986 |
| Matrad Oy | Professional & scientific | 1989 |
| Med-Service Oy | Health & social care | 2012 |
| Medi-Elo Oy | Wholesale & retail | 2006 |
| Merikiinteistö Illi Oy | Real estate | 1990 |
| Meriportin Hammaslääkärit Oy | Health & social care | 1996 |
| Mestaritallit Oy | Construction | 2015 |
| Mestrans Oy | Transport & logistics | 2023 |
| Metallimies Sami Turkkila Oy | Manufacturing | 2013 |
| Metpel oy | Construction | 2024 |
| MiL-Pilke Oy | Agriculture & fishing | 2010 |
| MikSa Solutions Oy | Wholesale & retail | 2026 |
| Mika Saarainen Oy | Transport & logistics | 2009 |
| Mikete Oy | Transport & logistics | 2011 |
| Mirella Siivous Oy | Administrative & support | 2015 |
| MittaMika Oy | Construction | 2020 |
| MixSix Palvelut Oy | Wholesale & retail | 2015 |
| Moneksi Oy | Wholesale & retail | 2022 |
| Monitoimi KT Oy | Administrative & support | 2022 |
| Moniurakointi Nokkanen Oy | Construction | 2019 |
| Mooney's Hamina Oy | Hospitality | 2024 |
| Muoviteollisuus Penttilä Oy | Manufacturing | 2002 |
| MuruVet Oy | Professional & scientific | 2025 |
| Muuronen Consulting Oy | Real estate | 2021 |
| Muuttopolku Oy | Transport & logistics | 2024 |
| Mäntlahden vesihuolto-osuuskunta | Water & waste | 2003 |
| N-Pap Oy | Transport & logistics | 2000 |
| N.J. Putki ja ilmalämpöpumppuasennus Oy | Construction | 2023 |
| NDB-Projektit Oy | Real estate | 2024 |
| NPT Project & Logistics Oy | Mining & quarrying | 2016 |
| NSS Project Oy | Wholesale & retail | 2012 |
| Nanoni Oy | Professional & scientific | 2024 |
| Nestor Group Oy | Construction | 2025 |
| Niemistön Lomamökit Ky | Hospitality | 2012 |
| Norados Oy | Professional & scientific | 2001 |
| Nordic Insurance Solutions Oy | Financial services | 2020 |
| Nordic Lashes Oy | Other services | 2025 |
| Norssi Consulting Oy | Administrative & support | 2022 |
| Norsviikin vesiosuuskunta | Water & waste | 2009 |
| Notahar Oy | Real estate | 2000 |
| Notorius AML Oy | Wholesale & retail | 2020 |
| O. Lääti Ky | Agriculture & fishing | 1983 |
| OOO "Resurs", sivuliike Suomessa | Agriculture & fishing | 2011 |
| Olehyvä Luonnontuote Oy | Manufacturing | 2005 |
| Olvex OY | Wholesale & retail | 2007 |
| OnniPet Oy | Wholesale & retail | 2022 |
| Oranssipaidat Oy | Arts & recreation | 2026 |
| Osuuskunta Vir-Ma | Administrative & support | 2011 |
| Other Plan Oy | Real estate | 2024 |
| Oy BPL Suomi-Finland Ltd | Financial services | 1996 |
| Oy DMM-Logistics Ltd | Transport & logistics | 2006 |
| Oy Emmeretail Finland Ltd | Wholesale & retail | 2018 |
| Oy Eurozakon Ltd | Administrative & support | 2012 |
| Oy Hacklin Hamiko Ltd | Transport & logistics | 1991 |
| Oy Haminan Kuntokeskus Syke Ab | Arts & recreation | 1994 |
| Oy KHL Development Ltd | Hospitality | 2019 |
| Oy Phoenix Collector Ltd | Water & waste | 1996 |
| Oy REJK Ltd | Professional & scientific | 1972 |
| Oy Safewood Ltd | Wholesale & retail | 1997 |
| Oy Sesla Ltd | Professional & scientific | 2008 |
| P.T. Kiinteistöpalvelut Oy | Administrative & support | 2008 |
| PG Hamina Oy | Other services | 2020 |
| PJ-Waffen-Guns Oy | Wholesale & retail | 1991 |
| Paine Group Oy | Construction | 2018 |
| Pajamotors oy | Other services | 2022 |
| Pakkanen & Co Oy | Professional & scientific | 2025 |
| Pampyölin Vesiosuuskunta | Water & waste | 2008 |
| Paperinjalostaja Joxpap Oy | Manufacturing | 2000 |
| Pasi Trans Oy | Transport & logistics | 1994 |
| Peltituote Jauhiainen Oy | Construction | 2008 |
| Penttilä Group Oy | Construction | 2023 |
| Perca Oy | Wholesale & retail | 2023 |
| Perkfin Oy | Manufacturing | 1997 |
| PhysioProStudios Avoin yhtiö | Health & social care | 2019 |
| Piharinki Oy | Administrative & support | 2019 |