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| Bluebond Oy | Nokia | 2016 |
| Blueflame Solutions Ab | Loviisa | 2024 |
| Bluefox Legal Tech Oy | Helsinki | 2008 |
| Bluehaze Oy | Kellokoski | 2022 |
| Bluelake Consulting Oy | Helsinki | 2016 |
| Bluendo Oy | Sulkavanjärvi | 2012 |
| Bluenor Oy | Helsinki | 2025 |
| Blueprint Prime Oy | Helsinki | 2026 |
| Bluesalo Oy | Jyväskylä | 2018 |
| Blueshirt Oy | Tuusula | 2024 |
| Bluesisland Oy | Lempäälä | 2026 |
| Bluestone Innovations Oy | Jääli | 2021 |
| Bluet Oy Ltd | Vantaa | 2016 |
| Bluetech Finland Oy | Helsinki | 2013 |
| Bluetech Oy | Helsinki | 2010 |
| Bluevir Oy | Hämeenlinna | 2016 |
| Blugrow Oy | Espoo | 2014 |
| BlunderCleanery Oy | Helsinki | 2024 |
| Blush Online Oy | Helsinki | 2024 |
| Bluuni Oy | Espoo | 2020 |
| Blääni Oy | Turku | 2018 |
| BnB Joensuu Oy | Joensuu | 2019 |
| Bnw Mainos Oy | Tampere | 2025 |
| BoBo Form Oy | Helsinki | 2026 |
| BoMentis Oy | Espoo | 2000 |
| BoP Man Oy | Kempele | 2025 |
| Board Advisor Group Oy | Helsinki | 2019 |
| Board Company Finland Oy | Helsinki | 2023 |
| Boardcoach Oy | Joensuu | 2017 |
| Boardman Oy | Helsinki | 2002 |
| BoardonBoard Oy | Helsinki | 2019 |
| Boardwalk Oy | Helsinki | 2022 |
| Bob Sprinkel IV Oy | Helsinki | 2021 |
| Bob The Robot Pictures Oy | Helsinki | 2014 |
| Bob the Llama Oy | Vantaa | 2026 |
| Bob the Robot Oy | Helsinki | 2004 |
| Bobcat Consulting Oy | Tampere | 2023 |
| Bobi.com Oy | Vaasa | 2016 |
| Bocalane Oy | Kauniainen | 2024 |
| Bocardo Multimedia Oy | Helsinki | 1985 |
| Bock Holding Oy | Helsinki | 2015 |
| Bock-Invest Oy | Nauvo | 1990 |
| Boco IP Oy Ab | Helsinki | 1996 |
| Bodhiworks Oy | Espoo | 2022 |
| Bodium Scan Oy | Turku | 2025 |
| Bodom Bodom Oy | Espoo | 2022 |
| Bodoni Oy | Pori | 1997 |
| Bodoworks Oy | Vantaa | 2022 |
| Bodwil Oy | Kotka | 2013 |
| Bofor Studios Oy | Espoo | 2020 |
| Bogskär Ab | Eckerö | 2020 |
| Bohao VC Oy | Siivikkala | 2024 |
| BohoLiving Oy | Selki | 2026 |
| Boier Capital Oy | Helsinki | 2007 |
| Boiler Consulting K E Salmi Oy | Tampere | 2011 |
| Boiling Point Oy | Helsinki | 2010 |
| Bois Invest Oy | Nivala | 2025 |
| Boit Oy | Helsinki | 2007 |
| Bojen Capital Oy | Helsinki | 2026 |
| Bokai Oy | Helsinki | 2026 |
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| Bokföring & Revision Söderberg Oy | Karjaa | 1990 |
| Bokföring Finne kommanditbolag | Vaasa | 1975 |
| Bokföring H & N Kirjanpito Öppet Bolag | Tammisaari | 2018 |
| Bokföring P-E Nyberg Kb | Karjaa | 1988 |
| Bokföringsbyrå Ab J & J Oy Tilitoimisto | Lapväärtti | 1989 |
| Bokföringsbyrå All-Bokföring kommanditbolag | Petolahti | 1997 |
| Bokföringsbyrå Balansfix Ab | Oravainen | 1989 |
| Bokföringsbyrå Da-Ka, öppet bolag | Mariehamn | 1994 |
| Bokföringsbyrå H. Ulfvens Kb | Pirttikylä | 1981 |
| Bokföringsbyrå Hindsberg Ab | Sipoo | 2021 |
| Bokföringsbyrå Ismene, Grüssner & Grüssner | Godby | 1993 |
| Bokföringsbyrå Karis Ekonomitjänst Kb | Karjaa | 1996 |
| Bokföringsbyrå Lundström Ab | Sipoo | 1983 |
| Bokföringsbyrå Prima Ab | Pietarsaari | 2021 |
| Bokföringsbyrå Stig Dahlström Ab, Kirjanpitotoimisto Stig Dahlström Oy | Helsinki | 2008 |
| Bokföringsbyrå Tililaskenta Ab - Tilitoimisto Tililaskenta Oy | Pietarsaari | 1997 |
| Bokföringsbyrå din bokförare Kb | Turku | 2012 |
| Bokföringsbyrån Asset Management Ab | Sannainen | 2002 |
| Bokföringshjälpen Finland AB | Tammisaari | 2026 |
| Bokföringssällskapet i Finland Ab | Pännäinen | 2005 |
| Bokföringstjänst J & M öppet bolag | Tammisaari | 2016 |
| Bokmal Ab | Maalahti | 2021 |
| Bold Solutions Oy | Espoo | 2018 |
| BoldIT Oy | Åminnefors | 2023 |
| Bolder & Finn Oy | Turku | 2021 |
| Bolder Development Oy | Helsinki | 2019 |
| Boldia Oy | Helsinki | 2026 |
| Boletus Capital Oy | Oulu | 2021 |
| Bolster Oy | Järvenpää | 2017 |
| Bolt Group Oy | Helsinki | 2016 |
| Bolted Oy | Espoo | 2022 |
| Bom Oy | Vantaa | 2010 |
| Bom Visual Oy | Vantaa | 2020 |
| Bomberg Oy | Kuusa | 2020 |
| Bombotti Oy | Helsinki | 2014 |
| Bomeo Operations Oy | Joensuu | 2024 |
| Bomoko Group Oy | Vantaa | 2024 |
| Bon Design Agency Oy | Helsinki | 2022 |