| Bageri Eken Ab Oy | Manufacturing | 2021 |
| Balance Audit Oy Ab | Professional & scientific | 1994 |
| Barely Ab Oy | Arts & recreation | 2022 |
| Beautyfill clinic ab | Health & social care | 2021 |
| Beccor Oy | Financial services | 2019 |
| Beefeaters öppet bolag | Arts & recreation | 1992 |
| Behzad Vaasa Oy | Hospitality | 2024 |
| Belle Lounge Oy | Hospitality | 2025 |
| Bendline Oy | Manufacturing | 2023 |
| Berg & Lieskoski Holding Oy Ab | Financial services | 2026 |
| Berg Trading Oy | Wholesale & retail | 2007 |
| Bergman Holding Ab | Arts & recreation | 2024 |
| Bertills & Jung Ab | Professional & scientific | 2018 |
| Bigday Festival Oy Ab | Arts & recreation | 2025 |
| Bill Henriksson Psykologtjänster AB | Health & social care | 2024 |
| BioAurora Oy | Energy | 2021 |
| Bioka Nordic avoin yhtiö | Wholesale & retail | 2016 |
| Birch Capital Oy | Financial services | 2020 |
| Birch Path Holding Oy | Financial services | 2026 |
| Bistro-Albert Oy | Hospitality | 1992 |
| Bitfound Ab | Information & communication | 2025 |
| Bjonhagen Capital Oy | Professional & scientific | 2019 |
| Björklund Digital Media Ab Oy | Professional & scientific | 2020 |
| Bloomshop Oy | Wholesale & retail | 2025 |
| Blue Line Taxi Vaasa Oy | Transport & logistics | 2026 |
| Bobi.com Oy | Professional & scientific | 2016 |
| Bock's Corner Brewery Oy | Manufacturing | 2003 |
| Bokföring Finne kommanditbolag | Professional & scientific | 1975 |
| Bon Invest Oy Ab | Real estate | 2009 |
| Bonnier News Finland Ab | Information & communication | 1998 |
| Bono Oy | Professional & scientific | 1986 |
| Bonumest Oy | Financial services | 2020 |
| Bostadsandelslaget John | Real estate | 1954 |
| Bostadsandelslaget Storalånggatan 5 - Asunto-osuuskunta Pitkäkatu 5 | Real estate | 1954 |
| Bostadsandelslaget Viktor | Real estate | 1943 |
| Bothnia Craft Company Öppet bolag | Manufacturing | 2019 |
| Botnia Artists Ab Oy | Professional & scientific | 2012 |
| Botnia Controls Oy | Professional & scientific | 2017 |
| Botnia RS Oy | Administrative & support | 2023 |
| Botnia Recon Group Oy | Education | 2012 |
| Botnia Ventures Oy Ab | Financial services | 2022 |
| Botnia-Rent Oy | Construction | 1989 |
| BotniaSähkö Oy | Construction | 2023 |
| Botniagroup Oy | Construction | 2014 |
| Braining Company Oy | Administrative & support | 2025 |
| Branch Invest Oy | Financial services | 2019 |
| Braw Solutions Oy Ab | Information & communication | 2022 |
| Breatech Finland Oy | Wholesale & retail | 2025 |
| Brian&Sisters Kauppa Oy Ltd | Wholesale & retail | 2021 |
| Bridge Ventures Oy Ab | Financial services | 2022 |
| BroAxis Oy | Other services | 2025 |
| Broman & Company Ab Oy | Financial services | 2021 |
| Broman Law Oy Ab | Professional & scientific | 2020 |
| Budjettihiiri Oy | Education | 2022 |
| Buildart Oy | Real estate | 2019 |
| BullMarkets Oy | Financial services | 2013 |
| BunnyPouch Oy | Wholesale & retail | 2024 |
| BusinessFactory Osk. | Administrative & support | 2009 |
| Bussiuni Oy | Information & communication | 2026 |
| Buyon Oy | Wholesale & retail | 2012 |
| ByggKonsult Stefan Pellfolk Ab | Professional & scientific | 2008 |
| ByggPoint Oy | Construction | 2025 |
| Bäck & Vilén Företagstjänst Ab | Professional & scientific | 2017 |
| C M Djupsjöbacka Oy Ab | Real estate | 2023 |
| C-H Nyholm Auto-Ylänkö Ky | Wholesale & retail | 1981 |
| CAFCA oy | Professional & scientific | 2012 |
| Café Ohlis, Avoin Yhtiö | Hospitality | 2001 |
| Care Vaasa OY | Health & social care | 2024 |
| CBI Europe B.V. Suomen sivuliike | Wholesale & retail | 2023 |
| Certum Accounting OY | Professional & scientific | 2013 |
| Cjw-Fastigheter AB | Real estate | 2018 |
| CK Marketing & Education öppet bolag | Wholesale & retail | 2004 |
| CLA Smeds Oy | Wholesale & retail | 2025 |
| CLean Contract Oy | Professional & scientific | 2015 |
| CNC-Tekniikka Oy | Manufacturing | 2013 |
| COMPALL Oy Ab | Information & communication | 2020 |
| Corner Garage OY | Other services | 2026 |
| Created by J.H. OY | Construction | 2020 |
| CTF Marketing Oy | Wholesale & retail | 2012 |
| CTF Sales Oy | Administrative & support | 2019 |
| CTF Solutions Oy | Administrative & support | 2009 |
| CTF-Isännöinti Oy | Real estate | 2004 |
| CY Medical Ab | Health & social care | 2026 |
| Café Farini Oy | Hospitality | 2009 |
| Calzone2 Oy | Hospitality | 2021 |
| CamBerry Oy Ab | Other services | 2017 |
| Cameleont palvelut Oy | Construction | 1982 |
| Caof Oy | Financial services | 2013 |
| Capbrothers Oy | Real estate | 2017 |
| Captain Barbershop Oy | Other services | 2025 |
| Captus Oy | Professional & scientific | 1989 |
| Car Shower cs oy | Other services | 2012 |
| Caravan Myllymäki Oy | Administrative & support | 2012 |
| Carelia Partners Oy | Arts & recreation | 1999 |
| Carlsson RPS Oy | Information & communication | 2026 |
| Carrot Pohjanmaa Oy | Administrative & support | 2008 |
| Cash-In Consulting Oy Ab | Administrative & support | 1986 |
| Cattila Oy | Financial services | 2023 |
| Cava Hair & Make-up Oy | Other services | 2015 |
| Cava Helsinki Oy | Other services | 2026 |