| 47 Music Avoin Yhtiö | Arts & recreation | 2014 |
| A & P Koski Oy | Construction | 2006 |
| Abia Oy | Professional & scientific | 2009 |
| Aktivos Oy | Professional & scientific | 2024 |
| AkvaBlast Suomi Oy | Manufacturing | 2020 |
| Appstorm oy | Wholesale & retail | 2015 |
| Aranova Oy | Real estate | 1994 |
| Craftmens Oy | Agriculture & fishing | 2018 |
| E. Latvanen Ky | Wholesale & retail | 1983 |
| EduBuild Oy | Professional & scientific | 2019 |
| Emicity Oy | Wholesale & retail | 1998 |
| Finn-KT OY | Construction | 1988 |
| Forise Oy | Transport & logistics | 2006 |
| Foxcare Oy | Construction | 2019 |
| Har-Be Oy | Manufacturing | 1989 |
| Heinolan Levy ja Lista Oy | Wholesale & retail | 1991 |
| Heinolan Metsäkuljetus Oy | Agriculture & fishing | 1975 |
| Heinolan Mäntyniemi Oy | Real estate | 1984 |
| Heinolan kirkonkylän Kylätalo Oy | Real estate | 2003 |
| Heinolatalo Oy | Real estate | 1991 |
| Houseman Oy | Wholesale & retail | 2011 |
| Huhdanpää Holding Oy | Financial services | 2018 |
| Häkkinen Oy | Other services | 1976 |
| Investment of Scandinavia IOS Oy | Financial services | 2020 |
| Italform Finland Oy | Construction | 1996 |
| JP-Tähti Ky | Wholesale & retail | 1998 |
| JSK Company Oy | Professional & scientific | 2025 |
| JTR-Yhtiö Oy | Construction | 1997 |
| JaLi Consulting oy | Professional & scientific | 2020 |
| Jumbo Ky M.Kronqvist | Manufacturing | 1972 |
| Kaari Investment Oy | Financial services | 2026 |
| Kaijan Kotileipä Ky | Manufacturing | 2008 |
| Kaivuri Janne Oy | Construction | 1999 |
| Karbelt Oy | Manufacturing | 1991 |
| Kari Kuusemo Oy | Transport & logistics | 1995 |
| Kati Klinga Oy | Wholesale & retail | 2010 |
| Kepilän Tila Oy | Agriculture & fishing | 2020 |
| Kiinteistö Oy Akkavuori | Real estate | 1994 |
| Kiinteistö Oy Kullasmarina | Hospitality | 2007 |
| Kiinteistö Oy Pertunmaan Kuusisaari | Real estate | 1992 |
| Kiinteistö Oy Plaaninkatu 5 | Real estate | 1973 |
| Kiinteistö Oy Riihikalliontie 35 | Real estate | 1998 |
| Kiinteistö Oy Sammontie 15 | Real estate | 1987 |
| Kiinteistö Oy Sammontie 6 Heinola kk | Real estate | 1987 |
| Kiinteistö Oy Sammontie 8 | Real estate | 2009 |
| Kiinteistö Porvari Oy | Real estate | 1990 |
| Kiinteistö Siekkinen Oy | Real estate | 2007 |
| Kiinteistöosakeyhtiö Heinolan Kyminkulma | Real estate | 1998 |
| Koneistamo Hemi Motors Ky | Wholesale & retail | 2000 |
| Koneurakointi Hirvikoski Oy | Transport & logistics | 1998 |
| KooVee Palvelut Oy | Construction | 2020 |
| Koti- ja Pihapalvelu Tucare Oy | Health & social care | 2017 |
| Kuljetusliike H ja M Ronkainen | Agriculture & fishing | 1981 |
| Kusmiku Oy | Hospitality | 2016 |
| Kuurapuu Oy | Real estate | 2021 |
| Laaturakenne Toivanen Oy | Construction | 2011 |
| Lahden Jäähdytinhuolto Oy | Other services | 1993 |
| Led MRM Oy | Professional & scientific | 2026 |
| Maanrakennus KiValt Oy | Construction | 2007 |
| Macala Oy | Real estate | 1988 |
| Metsäkuljetus Heikki Nurminen Ky | Transport & logistics | 1980 |
| Metsänhoito Lehtinen avoin yhtiö | Agriculture & fishing | 2001 |
| Mittatehdas Oy | Professional & scientific | 2004 |
| Mäntyharjun Suittimäki Oy | Agriculture & fishing | 1991 |
| Nevalan Kiinteistö Oy | Real estate | 1938 |
| Nokelaisen Melissa Group Oy | Wholesale & retail | 1992 |
| Nosse Oy | Wholesale & retail | 2017 |
| Nuohous Kuisma Oy | Administrative & support | 2024 |
| O.R.C. Ideas Oy | Real estate | 1992 |
| Orasmaa Oy | Wholesale & retail | 1985 |
| PSV-Rakennus Oy | Construction | 2007 |
| Palvelumaster Oy | Wholesale & retail | 2000 |
| Pannu Consulting Oy | Professional & scientific | 2011 |
| Pareoper Oy | Professional & scientific | 2024 |
| Perhekoti Koivu ja Tähti Oy | Health & social care | 2007 |
| Perhekoti Toivola Oy | Health & social care | 2009 |
| Pienkonehuolto Siekkinen Oy | Wholesale & retail | 2007 |
| Pikkupeikko Oy | Financial services | 2024 |
| Porvari Group Oy | Real estate | 2018 |
| Quuhun Oy | Professional & scientific | 2021 |
| RS-Idea Oy | Wholesale & retail | 2012 |
| Rakennus ja Pinnoitus Boman Ky | Construction | 2006 |
| Rakennus ja Saneeraus A. Suomalainen Oy | Construction | 2019 |
| Rakennuspalvelu Kontulainen Oy | Construction | 2003 |
| Rakennuspalvelu R.J.Hämäläinen Oy | Construction | 2008 |
| Reli-Kone Oy | Construction | 1994 |
| Rihun ATK Oy | Information & communication | 2021 |
| Rosmina Oy | Transport & logistics | 1995 |
| RuusukeDesign Oy | Manufacturing | 2022 |
| SS Saneeraus Oy | Construction | 2021 |
| Sakola Oy | Wholesale & retail | 1988 |
| Saneeraus Varjonen Ky | Construction | 2013 |
| Santa Marina Oy | Hospitality | 2022 |
| Sasmetor Oy | Manufacturing | 1985 |
| Sectomo Oy | Manufacturing | 2006 |
| SirService Oy | Health & social care | 2025 |
| Sivema Ky | Hospitality | 1989 |
| Spirilli Oy | Manufacturing | 2007 |
| Stop 'n Go Grilli Aho Ky | Hospitality | 2003 |
| Suomen Koto Oy | Professional & scientific | 2012 |