| Aito Pinta Oy | Construction | 2021 |
| Aito Rental Oy | Real estate | 2025 |
| Akku-Tarvike O ja I Määttälä Ky | Wholesale & retail | 1976 |
| Akku-Teho Marine Oy | Wholesale & retail | 1988 |
| Aktiebolaget Rebeckorna i Karleby | Real estate | 1988 |
| Akvaset Oy | Wholesale & retail | 1990 |
| Al Wakeel OY | Wholesale & retail | 2025 |
| Ala-Kopsala Oy | Agriculture & fishing | 2021 |
| Ala-Korpi Service Oy | Health & social care | 2023 |
| Alanna Avoin yhtiö | Wholesale & retail | 2006 |
| AlchemyWelds Oy | Manufacturing | 2026 |
| Alfame Group Oy | Information & communication | 2026 |
| Alfame Systems Oy | Information & communication | 2004 |
| Alitustekniikka Dahlbacka Oy | Construction | 2001 |
| Alstena Oy | Professional & scientific | 1993 |
| Amanihoiva Kotihoito Oy | Health & social care | 2015 |
| Ambient Audio Oy | Wholesale & retail | 2011 |
| Amis Groupe Avoin yhtiö | Transport & logistics | 2008 |
| Ananas Group Oy | Professional & scientific | 2024 |
| Andelslaget Pimjalo Gård Osuuskunta | Hospitality | 1998 |
| Anniina Juuti Designs Oy | Arts & recreation | 2024 |
| Annika Sandbacka Kb | Real estate | 2005 |
| Antero Norppa Oy | Wholesale & retail | 1973 |
| Antti Laulumaa Ky | Wholesale & retail | 2004 |
| Antti Pekka Ahonen Oy | Wholesale & retail | 2002 |
| Apex Automation Oy | Professional & scientific | 1994 |
| Aplicator System Aktiebolag, filial i Finland | Manufacturing | 2009 |
| Aplories Oy | Wholesale & retail | 2023 |
| Arctic Cold Holding Oy | Financial services | 2000 |
| Arctic Pole Ltd Oy | Administrative & support | 2021 |
| Arde Systems Oy | Manufacturing | 2009 |
| AreenaFysio Oy | Health & social care | 2026 |
| Arioso Seppo Halinen Oy | Wholesale & retail | 1989 |
| Arkkitehtitoimisto Matti Rajamaa Oy | Professional & scientific | 2025 |
| Arkkitehtitoimisto Park Oy | Professional & scientific | 2011 |
| Arkkitehtitoimisto Patina Oy | Professional & scientific | 2021 |
| AsMe Oy | Construction | 2021 |
| Asab Oy | Professional & scientific | 2025 |
| Asella Oy | Professional & scientific | 2022 |
| Asianajotoimisto Kaitaluoma Oy | Professional & scientific | 2003 |
| Asianajotoimisto Kynnäs Oy | Professional & scientific | 2020 |
| Asianajotoimisto Sippola Oy - Advokatbyrå Ab | Professional & scientific | 1990 |
| Asianajotoimisto Talviaro Oy | Professional & scientific | 2022 |
| Asiantuntijanne Oy | Wholesale & retail | 2017 |
| Aspen venture Oy | Financial services | 2025 |
| Asshole Records Oy | Manufacturing | 2020 |
| Athlefy Oy | Information & communication | 2025 |
| Auditing and Consulting Auco Oy | Professional & scientific | 2009 |
| Auno Catering Oy | Hospitality | 2025 |
| Aurinko Media Company Oy Ltd | Manufacturing | 1996 |
| Autio Caravan Oy | Administrative & support | 2020 |
| Auto Enlund Oy | Wholesale & retail | 2016 |
| AutoKimmo Oy | Wholesale & retail | 2022 |
| Autohuolto Nortom Oy | Other services | 2024 |
| Autohuolto Turpeinen Oy | Wholesale & retail | 2012 |
| Autokorjaamo Kokkolan Autoexpertti Oy | Other services | 2014 |
| Automaa Oy | Wholesale & retail | 2000 |
| Automaalaamo J.Fix Oy | Other services | 2006 |
| Automaalaamo Kokko-Color Oy | Other services | 2008 |
| Automaalaamo Tähti Oy | Other services | 2014 |
| Automyynti Rainer Johnson Oy | Wholesale & retail | 2004 |
| Autonhoito H&H Oy | Other services | 2023 |
| Avain Kodit Oy - Avain Hem Ab | Real estate | 2021 |
| Avansia Oy | Health & social care | 2026 |
| Avoin yhtiö Kaj Hägg | Wholesale & retail | 2001 |
| Avoin yhtiö Kalopsi | Wholesale & retail | 1989 |
| Avoin yhtiö Kokkolan Konekeskus | Wholesale & retail | 1968 |
| Awita Oy | Professional & scientific | 2016 |
| Awita Partners Oy | Professional & scientific | 2016 |
| B Hästbacka Oy | Real estate | 2002 |
| B&C Handling Ab | Real estate | 2021 |
| B&C Holding Ab | Financial services | 2026 |
| B-Account OY AB | Professional & scientific | 2016 |
| B-Varaosat Kangas Avoin yhtiö | Other services | 2011 |
| BABYCITY&PELLAVAPUOTI Ky | Wholesale & retail | 2007 |
| Baromtex Comp. OY | Wholesale & retail | 2018 |
| BAZ Enterprises Oy | Transport & logistics | 2023 |
| BCK Service Oy | Transport & logistics | 2023 |
| BEAUTY PRODUCTS KOKKOLA Oy | Wholesale & retail | 2019 |
| BEEA Design Oy | Manufacturing | 2017 |
| BH Invest Oy | Real estate | 2021 |
| Blue Lagoon Sailing OY | Administrative & support | 2012 |
| BLUE WAVE Oy | Wholesale & retail | 1981 |
| BT Events Oy | Administrative & support | 2024 |
| BT Invest Oy | Financial services | 1979 |
| BW-Marketing Oy | Manufacturing | 1994 |
| Badi Holding Oy | Real estate | 2024 |
| Beatleen Oy | Real estate | 2020 |
| Beauty By Emilia Oy | Other services | 2024 |
| Beebs'fashion Kb | Wholesale & retail | 1986 |
| Beer30 Oy | Hospitality | 2024 |
| Befix Oy Ab | Real estate | 2019 |
| Berion Ab | Hospitality | 2025 |
| Berryfun Ab Oy Ltd | Manufacturing | 2021 |
| Best-Steel Oy | Construction | 2014 |
| BigNicci Oy | Hospitality | 2006 |
| Bimark Oy | Manufacturing | 1985 |
| Bistro Ravintola Roja Oy | Hospitality | 2024 |
| Bitjoiner Ab Oy | Information & communication | 2019 |
| Bitma Oy | Information & communication | 2019 |