| 1587 Kaija Ainassaari Oy | Wholesale & retail | 2017 |
| 1986 Lehtelä Oy | Wholesale & retail | 1986 |
| 2xJ International Oy | Wholesale & retail | 2022 |
| 3D-Suunnittelu Jaakola Oy | Professional & scientific | 2020 |
| 5S Service Oy | Professional & scientific | 2024 |
| 5SCAP Oy | Financial services | 2021 |
| 5T Invest OY | Financial services | 2020 |
| A&I Kiinteistötekniikka Oy | Construction | 2018 |
| A-Rengas Oy Ylivieska | Wholesale & retail | 2006 |
| A-Toimitilat Oy | Real estate | 2024 |
| AADuuni Oy | Administrative & support | 2024 |
| AG-Huttu Oy | Wholesale & retail | 2002 |
| AGLO Oy | Professional & scientific | 1981 |
| AHM Yhtiöt Oy | Construction | 2025 |
| AJH Tech Oy | Construction | 2026 |
| AJS-Kiinteistöt Oy | Wholesale & retail | 2010 |
| AKR Capital Oy | Real estate | 2021 |
| Anipe OY | Real estate | 2014 |
| ATM Kiinteistöt Ky | Construction | 1979 |
| AVELOGroup Oy | Wholesale & retail | 2025 |
| Aakula Kiinteistöt Oy | Real estate | 2014 |
| Aavasolutions Oy | Construction | 2019 |
| Aidosti Oy | Education | 2024 |
| Aimo Kortteen Konepaja Oy | Manufacturing | 1993 |
| AironMaid Oy | Construction | 2017 |
| Alanko Invest Oy | Financial services | 2009 |
| Alanko Yhtiöt Oy | Professional & scientific | 2025 |
| Alutec Group Oy | Professional & scientific | 2018 |
| Alutec Oy | Manufacturing | 2020 |
| AnSa Holding Oy | Real estate | 2015 |
| Angelina Trading Oy | Wholesale & retail | 2016 |
| Antti-Roiko Invest Oy | Real estate | 1980 |
| Anvicon Oy | Construction | 2025 |
| Arimaso Oy | Real estate | 2020 |
| Arkkitehtisuunnittelu Niskanen Oy | Professional & scientific | 2006 |
| Arkkitehtitoimisto Paloranta Oy | Professional & scientific | 1994 |
| Arsell Oy | Professional & scientific | 2019 |
| Arte Ornament avoin yhtiö | Construction | 1997 |
| Arvo Invest Nordic Oy | Financial services | 2012 |
| Arvo Sijoitusosuuskunta | Financial services | 1920 |
| Arvodata Oy | Wholesale & retail | 2019 |
| Asennus Tuomaala Oy | Construction | 2016 |
| Asianajotoimisto Keskitalo Oy | Professional & scientific | 2017 |
| Asianajotoimisto Takala Oy | Professional & scientific | 1982 |
| Asko Männistö Oy | Education | 1993 |
| Asko Rasmus Oy | Real estate | 1986 |
| Audiohex Oy | Wholesale & retail | 2022 |
| AuroraHut Oy | Hospitality | 2018 |
| Aution Auto Oy | Other services | 1983 |
| Aution palvelut Oy | Administrative & support | 2025 |
| Auto Assist Ky | Wholesale & retail | 1990 |
| Auto- ja Traktorihuolto Suihkonen & Pihlajamaa Oy | Manufacturing | 1989 |
| Autoliike Haanpää Oy | Wholesale & retail | 1982 |
| Autoliike Kymppi Plus Oy | Wholesale & retail | 2007 |
| Automaalaamo Kulmala Ky | Other services | 1991 |
| Autopalvelu Parkkila Oy | Other services | 2011 |
| Autopurkaamo J.Koskela Ky | Wholesale & retail | 2013 |
| Autotalo Jorma Savusalo Oy | Wholesale & retail | 1990 |
| Avoin yhtiö Veli-Martti Sivula | | 1990 |
| Axaoker Oy | Professional & scientific | 2020 |
| Beautypiste Oy | Other services | 2020 |
| Betker Oy | Manufacturing | 1995 |
| Biominerals Finland Oy | Professional & scientific | 2017 |
| Bloom Aesthetic Medicine Oy | Other services | 2023 |
| Bondata Ylivieska Oy | Administrative & support | 2010 |
| Boss Man Barbershop Ay | Other services | 2022 |
| Bossman barbershop Ylivieska Oy | Other services | 2026 |
| Businessdata Pekka Typpö Ky | Wholesale & retail | 1987 |
| Bytedev Oy | Information & communication | 2020 |
| Camtronic Invest Oy | Financial services | 2023 |
| Camtronic Oy | Manufacturing | 2001 |
| Cetula Invest Oy | Real estate | 2020 |
| Citrus Foodsa Oy | Hospitality | 2014 |
| Clifftor Ky | Financial services | 2012 |
| Cowboy Kahvilat Oy | Hospitality | 2013 |
| Cranop Oy | Construction | 2025 |
| Deal With It Oy | Financial services | 2018 |
| Deltapak Oy | Manufacturing | 1994 |
| Den's Group Oy | Wholesale & retail | 2023 |
| Desem Oy | Professional & scientific | 2021 |
| E-luku Timlin Oy | Professional & scientific | 2023 |
| E. Nurkkala Oy | Professional & scientific | 2026 |
| E.J.P Tuomikoski Oy | Transport & logistics | 2007 |
| E.T. Listat Oy | Manufacturing | 1972 |
| ESEKO Holding Oy | Financial services | 2012 |
| Experiment JH OY | Professional & scientific | 2008 |
| Eagle Media Oy | Professional & scientific | 2023 |
| Edustusliike Christer Karlsson Ky | Wholesale & retail | 1985 |
| Edustusliike Hintsala Oy | Financial services | 2011 |
| Eijan Kangas ja Leikkuu Oy | Wholesale & retail | 1990 |
| Ekser Oy | Transport & logistics | 2021 |
| Eljas Rantala Oy | Construction | 2017 |
| Eläinlääkärit Katri ja Antti Helminen Ky | Professional & scientific | 1987 |
| Energet Oy | Professional & scientific | 2022 |
| Energia-Lehkoset Ay | Wholesale & retail | 2013 |
| Entersec Oy | Administrative & support | 2011 |
| Erikoishammasteknikko Anja Huhtakangas Oy | Health & social care | 1988 |
| Erikoishammasteknikko Tuula Komujärvi Oy | Manufacturing | 2020 |
| Erä-Jorma Oy | Administrative & support | 2008 |
| Esencia Oy | Education | 2025 |