| Casto AS | Naustdal | 2021 |
| Catch 112 Brann & Redning AS | Raufoss | 2011 |
| Catchy Dansestudio AS | Fyllingsdalen | 2017 |
| Cathleen Lackner AS | Hildre | 2018 |
| Cathrine Midtgård - Impact AS | Horten | 2021 |
| Cathrine With Holm AS | Strømmen | 2025 |
| Cato Myhrvold Trafikkskole AS | Drøbak | 1979 |
| Cato Zahl Pedersen AS | Bjørnemyr | 1995 |
| Cato's House of Education AS | Heggedal | 2014 |
| Catslide AS | Oslo | 2012 |
| Cava Cruise Control AS | Oslo | 2020 |
| CD Holding AS | Fagerstrand | 2012 |
| Cefalon AS | Oslo | 2014 |
| Celeres Da | Oslo | 2005 |
| Celina Invest AS | Oslo | 2017 |
| Celina Karine AS | Oslo | 1982 |
| Celius Invest AS | Hemnskjela | 2020 |
| Cenmirari AS | Bergen | 2023 |
| Center to Improve AS | Oslo | 2008 |
| Centrum Asker & Bærum Verk Trafikkskole AS | Asker | 1999 |
| Centrum Bærland Trafikkskole AS | Tønsberg | 2013 |
| Centrum Trafikkskole Ans | Vettre | 1991 |
| Centrum Trafikkskole AS | Rådal | 1986 |
| Centrum Trafikkskole AS | Trondheim | 1995 |
| Centrum Trafikkskole Tilhenger AS | Rådal | 2019 |
| Cephalo AS | Trondheim | 2025 |
| Cflo AS | Haslum | 2024 |
| Chaga Studio AS | Florø | 2026 |
| Change Balanse AS | Tromsø | 2023 |
| CHANGE20 AS | Beitostølen | 2019 |
| Changemakers AS | Oslo | 2019 |
| Charlotte Bårtvedt Eriksen AS | Kristiansand S | 2024 |
| Charlotte Og Marius Holding AS | Langhus | 2023 |
| Charlottenlund Barnehage AS | Tromsø | 2023 |
| Charon | Nl-6706 Jb Wageningen | 2021 |
| Chauffeur Trafikkskole AS | Stathelle | 2022 |
| Chawla Invest AS | Oslo | 2016 |
| Check Trafikkskole AS | Mjøndalen | 2022 |
| CHECK-6 International Nuf | Stavanger | 2012 |
| CHECK-6 Norway AS | Stavanger | 2012 |
| Chi Kurs Og Trening AS | Lepsøy | 2016 |
| Chiball Norge | Se-673 91 Charlottenberg | 2017 |
| Childrens International School Fredrikstad AS | Gamle Fredrikstad | 2011 |
| Childrens International School Moss AS | Moss | 2014 |
| Childrens International School Sarpsborg AS | Sarpsborg | 2018 |
| Childrens International School Ski AS | Jessheim | 2020 |
| Chohan Level Consulting AS | Oslo | 2022 |
| Chon Ji Taekwondo Academy AS | Hokksund | 2013 |
| Christensen Training AS | Oslo | 2020 |
| Christer Berens AS | Haslum | 2017 |
| Christian Førde Trafikkskole AS | Bodø | 2015 |
| Christiania Barnehave Bjørndal AS | Oslo | 2016 |
| Christiania Barnehave Høybråten AS | Oslo | 2016 |
| Christiania Barnehave Nordstrand AS | Oslo | 2016 |
| Christiania Barnehaver AS | Snarøya | 1997 |
| Christiania Vekterservice AS | Vinterbro | 2024 |
| Christiansen Ole Petter AS | Hokksund | 1977 |
| Christin Dahl AS | Kristiansand S | 2023 |
| Christina Eilertsen AS | Haugesund | 2024 |
| Christina Stusvik AS | Oslo | 2005 |
| Christine Høst AS | Oslo | 2023 |
| Christine Høst Holding AS | Oslo | 2023 |
| Christinelund Barnehage AS | Borgenhaugen | 2025 |
| Cidi Norge Da | Ridabu | 2004 |
| Cinemarine AS | Oslo | 2026 |
| Circus Bazaar Group Norway AS | Oslo | 2013 |
| City Trafikkskole AS | Kristiansund N | 1978 |
| City Trafikkskole AS | Bergen | 2004 |
| CK Akademiet AS | Notodden | 2024 |
| Cleaning AS | Straumsgrend | 2021 |
| Clengpeerson AS | Randaberg | 2017 |
| Climate Creativity AS | Oslo | 2020 |
| Climate Finance AS | Kristiansand S | 2022 |
| Clippers Studio AS | Hundvåg | 2018 |
| Clockwork Holding AS | Blomsterdalen | 2015 |
| Close AS | Trondheim | 2016 |
| Closing the Gap AS | Oslo | 2023 |
| Club Lento AS | Stavanger | 2026 |
| Co-Pilot Paragliding Norway AS | Volda | 2026 |
| Coach Bente Rabba AS | Kapp | 2019 |
| Coach Berge Nuf | Førde | 2023 |
| Coach Bjørndal AS | Bergen | 2024 |
| Coach Grethe AS | Jessheim | 2022 |
| Coach Loyd AS | Saudasjøen | 2022 |
| Coach Magnussen AS | Leknes | 2023 |
| Coach North AS | Bjerkvik | 2020 |
| Coach Nybøe-Olsen AS | Sandnes | 2025 |
| Coach Schulstad AS | Fredrikstad | 2025 |
| Coach Slater AS | Oslo | 2025 |
| Coach Together AS | Skedsmokorset | 2023 |
| Coach Van Nguyen AS | Oslo | 2024 |
| Coach Vinge AS | Frosta | 2025 |
| Coasteering AS | Fjell | 2017 |
| Cobra Associates Limited Nuf | Sandnes | 2014 |
| Cocoa Lotus Unlimited AS | Tananger | 2018 |
| Collecta Pretio Holding AS | Oslo | 2021 |
| Collettløkka Barnehage SA | Oslo | 1999 |
| Communicaid Group Limited | London Ec3A 5Bu | 2010 |
| Company Stories AS | Vettre | 2012 |
| Compendium AS | Rennesøy | 1996 |