| By Vigdis AS | Manufacturing | 2021 |
| By-Bo AS | Real estate | 2021 |
| Byblos Oriental Gril AS | Hospitality | 2015 |
| Bydelshus AS | Real estate | 2016 |
| Bygg & Bolig Holding AS | | 2026 |
| Bygg Kunst Og Design Butikk AS | Wholesale & retail | 2015 |
| Bygg Og Rehabtjenester AS | Construction | 2024 |
| Byggaktuelt Media AS | Information & communication | 2023 |
| Byggebygge Nuf | Professional & scientific | 2009 |
| Byggefirma Svinndal AS | Construction | 2017 |
| Byggflyt AS | Real estate | 2024 |
| Bygghuset Eiendom AS | Real estate | 1998 |
| Byggmester Dahl Og Daler AS | Construction | 2001 |
| Byggmester De Lange Og Sørensen AS | Construction | 2006 |
| Byggmester Frette AS | Construction | 2003 |
| Byggmester Harald Langemyhr AS | Construction | 2001 |
| Byggmester Hoffmann AS | Construction | 2016 |
| Byggmester Petter Stenberg AS | Construction | 2024 |
| Byggmester Stensbak AS | Construction | 2017 |
| Byggmester Svendsen AS | Construction | 1994 |
| Byggmester Thomas Lindhjem AS | Construction | 2000 |
| Byggmester Ugland & Eilerås AS | Construction | 2016 |
| Byggmester Vedvik AS | Construction | 1997 |
| Byggmesterfirma NL Bygg AS | Construction | 2015 |
| Byggmesterhus AS | Construction | 1987 |
| Byggshopper AS | Wholesale & retail | 2015 |
| Byggtaksering AS | Professional & scientific | 2003 |
| Byggtek Da | Professional & scientific | 2003 |
| Bylidal AS | Information & communication | 2026 |
| Bystranda Eventhus Tønsberg AS | Administrative & support | 2024 |
| Byteshift AS | Information & communication | 2021 |
| Bytteskjerm AS | Wholesale & retail | 2015 |
| Bør AS | Manufacturing | 2016 |
| Bør Økonomi AS | Professional & scientific | 1967 |
| C Invest AS | Professional & scientific | 2005 |
| C M Olsen AS | Transport & logistics | 1990 |
| C12H22O11 Holding AS | | 2026 |
| Caelja AS | Real estate | 2017 |
| Cafe-M Tønsberg 18 AS | Hospitality | 2018 |
| Calma One AS | Real estate | 2023 |
| Calyx Capital AS | | 2026 |
| Cam Oasen AS | Wholesale & retail | 2016 |
| Camak Management AS | Arts & recreation | 2005 |
| Camellia AS | Hospitality | 1998 |
| Capio AS | Real estate | 2005 |
| Capnova AS | Professional & scientific | 1998 |
| Capnova Handelseiendommer AS | Real estate | 2012 |
| Capnova Hanthosundet AS | Real estate | 2003 |
| Capnova Holding AS | Real estate | 2003 |
| Capnova K10 Eiendom AS | Real estate | 2001 |
| Caravan Gruppen AS | Wholesale & retail | 2024 |
| Carl & Venner AS | Professional & scientific | 2010 |
| Casamovil AS | Hospitality | 2010 |
| Casina AS | | 2022 |
| Casper Produkt - Advokat Og Veiledning AS | Professional & scientific | 2017 |
| Castellana AS | | 2019 |
| Catseye Film AS | Information & communication | 2012 |
| Catwalk Company AS | Professional & scientific | 2004 |
| Cawich Holding AS | | 2021 |
| CB Group AS | Wholesale & retail | 2019 |
| Cc-Glass Tønsberg AS | Manufacturing | 2011 |
| Ceelab AS | Wholesale & retail | 2010 |
| Celnic AS | Real estate | 2006 |
| Celnic Eiendom AS | Real estate | 2017 |
| Celnic Invest AS | Real estate | 2020 |
| Central Telecom AS | Construction | 2024 |
| Centrum Bærland Trafikkskole AS | Education | 2013 |
| Chablis Invest AS | | 2026 |
| Christian Smedsrud AS | Health & social care | 2015 |
| Christiansen & Roberg AS | Professional & scientific | 2024 |
| Christo Holding AS | Real estate | 2006 |
| Cicero Digital Og Grafisk AS | Manufacturing | 2016 |
| Cici Holding AS | Real estate | 2005 |
| Cimexa AS | Professional & scientific | 2001 |
| CJF Holding AS | | 2021 |
| CKR AS | Professional & scientific | 2015 |
| Classicfrisør AS | Other services | 2021 |
| Clear Sky Holding AS | Real estate | 2007 |
| Clearflow AS | Construction | 2026 |
| Clinic Ethic AS | Wholesale & retail | 2000 |
| Clipp Frisør AS | Other services | 2016 |
| Cloft Consulting AS | Professional & scientific | 2017 |
| Cloudoffice AS | Information & communication | 2004 |
| CM Mobility AS | Construction | 2022 |
| CN Investering AS | | 2019 |
| CNP AS | Administrative & support | 2011 |
| CNP Holding AS | Administrative & support | 2015 |
| Co-Partner AS | Professional & scientific | 2001 |
| Coach.No AS | Information & communication | 2013 |
| Cocreators AS | Professional & scientific | 2021 |
| Code Factory AS | Information & communication | 2017 |
| Cogan Consulting AS | Information & communication | 2026 |
| Colorpro AS | Professional & scientific | 2000 |
| Combineering | Water & waste | 2014 |
| Comet Growth AS | Professional & scientific | 2023 |
| Comet Holding AS | Professional & scientific | 2015 |
| Comet Partner AS | Professional & scientific | 2023 |
| Conatus TBG AS | Health & social care | 2019 |
| Conquer AS | Real estate | 2019 |
| Conradis Utvikling AS | Real estate | 2011 |