| Carpi Tech CZ Sro | Oslo | 2016 |
| Carrera Industrier AS | Sandnes | 2006 |
| Cartago AS | Høvik | 2014 |
| Carzzin Service AS | Oslo | 2025 |
| Casa Aurora Borealis Opplevelser AS | Oslo | 2020 |
| Casa Care AS | Bybrua | 2023 |
| Casa Marina AS | Oslo | 1998 |
| Casa Trading Petersson & Thesen Da | Oslo | 1988 |
| Casa Vacanze AS | Sandefjord | 2007 |
| Casagrand AS | Kristiansand S | 2024 |
| Cascade Eigedom AS | Os | 2014 |
| Cash Back Norge AS | Oslo | 1991 |
| Cash Management Security AS | Vestfossen | 1991 |
| Casita Arctic Experience AS | Tromsdalen | 2025 |
| Casol AS | Greåker | 2021 |
| Cast Consulting Ltd | Lytham St. Annes Fy8 5Ft | 2019 |
| Castille Atlantic Inc. Nuf | Oslo | 2025 |
| Castor Finans Da | Oslo | 2002 |
| Cat Tech (Europe) Ltd | Oslo | 2005 |
| Cataleya Clean AS | Straume | 2019 |
| Catalyst Rating Ltd | Milton Keynes Mk19 6An Northants | 2026 |
| Catch Certificate SA | Bergen | 2009 |
| Catch Nord AS | Bodø | 2019 |
| Catch Rekruttering AS | Oslo | 2022 |
| Catch Up AB | Se-721 26 Vesterås | 2012 |
| Caterpillar Financial Services (UK) Limited | West Midlands B90 4Bn | 2024 |
| Catharina Horn AS | Oslo | 1995 |
| Cathay Norge Da | Kodal | 2006 |
| Cathie Associates Limited | Sandnes | 2013 |
| Cato Mørk AS | Kopperå | 2020 |
| Catrico AS | Oslo | 2020 |
| Caution Club Da | Oslo | 2006 |
| Caval Rekruttering AS | Stabekk | 2021 |
| Cavator AS | Stjørdal | 2019 |
| Cave Music Live Production AS | Enebakk | 2008 |
| Caverion Sverige AB | Se-126 30 Hägersten | 2006 |
| Cavok SA | Leirsund | 2016 |
| CB Enviromental Services Limited | Aberdeenshire Ab22 8Dd Scotland | 2020 |
| CB Lyd Og Lys Ans | Oslo | 2007 |
| CB Multidrift Entreprenør AS | Slattum | 2021 |
| CB Partner Harstad AS | Tromsø | 2018 |
| CB Partner Tromsø AS | Tromsø | 2015 |
| CB Production AB | Se-429 42 Särö | 2023 |
| Cba Fagformidling AS | Oslo | 2003 |
| Cba Infra AS | Larvik | 2002 |
| CBP Tours AS | Skien | 2024 |
| Cbre Limited | London W1G 0Ng England | 2014 |
| Cbre Managed Services Limited | London, Se1 0Hl | 2025 |
| Cbsbutler Ltd | Oslo | 2012 |
| CC Eiendom Drift AS | Gjøvik | 2000 |
| CC Partner Drammen AS | Drammen | 2006 |
| CC Partner Lillestrøm AS | Lillestrøm | 2005 |
| Cc-Foss AS | Borgenhaugen | 2024 |
| CCC Holding AS | Nyborg | 2011 |
| CCC Nordic | Dk-2300 København S | 2019 |
| CCM Rights AS | Kokstad | 2023 |
| CCT Group AS | Bergen | 2011 |
| Cct&E Services Ltd Nuf | Aberdeen Ab12 3Ef | 2020 |
| CDM Holding 2016 Aps | Dk-8000 Aarhus C | 2023 |
| Ce Eventutleie AS | Blomsterdalen | 2026 |
| Ce Utleie AS | Klepp Stasjon | 2019 |
| Cebo AS | Kristiansund N | 2013 |
| Cedar AS | Rennesøy | 2015 |
| Cefo Tech AS | Harstad | 2026 |
| Ceg Rental AS | Sundebru | 2021 |
| Cegal LLC | Stavanger | 2015 |
| Cegro Utleie AS | Randaberg | 2007 |
| Celcius Tours AS | Åkrehamn | 2012 |
| Celebi AS | Oslo | 2025 |
| Celebrity Fight Night AS | Skien | 2026 |
| Celema Reiser AS | Oppegård | 2022 |
| Celerant Consulting Ltd | Surrey Tw9 2Jy England | 1999 |
| Celice AS | Bergen | 2007 |
| Celis - T'Seyen Nuf | Be-2288 Bouwel | 2025 |
| Cellaed Scandinavia AS | Jessheim | 2021 |
| Cellbrite Solutions Limited | Ec1V 9Ee London | 2013 |
| Cellmark AB | Se-411 04 Göteborg | 2016 |
| Celn Limited | Merseyside Ch43 7Su | 2020 |
| Celsus AS | Olsvik | 2008 |
| Celtic Marine (Hong Kong) Limited | Wanchai | 2014 |
| Cenaro Bilutleie AS | Nyborg | 2025 |
| Cengage Learning (Emea) Ltd | Sandnes | 2003 |
| Cenit Eiendom AS | Vinterbro | 2000 |
| Center for Peace and Development Ans | Oslo | 2004 |
| Centerpoint AS | Trollåsen | 2002 |
| Central Security AS | Trollåsen | 2023 |
| Centre Internacional De Metodes Numerics a L'Enginyeria | Es-08034 Barcelona | 2022 |
| Centric IT Solutions Sweden AB | Se-176 25 Sundbyberg | 2018 |
| Centrum Legekontor Lørenskog AS | Lørenskog | 2025 |
| Centrum Vinduspuss & Rengjøringsbyrå AS | Oslo | 1978 |
| Centurion UK Rentals & Services Limited | Aberdeen Ab23 8Jw Scotland | 2024 |
| Cepa Holding AS | Eina | 2005 |
| Cephalon Norge AS | Drammen | 1984 |
| Ceralia AS | Gressvik | 2014 |
| Cert Record 59 Ltd Nuf | London Southgate N14 6Qh England | 2025 |
| Certificat AS | Hønefoss | 2016 |
| Certified Oilfield Rentals LLC | Abu Dahbi | 2013 |
| Certified Oilfield Rentals Ltd | Bahamas | 2013 |
| Cervus Jaktreiser AS | Høydalsmo | 2018 |
| Cesur Norway Nuf | Se-26253 Ängelholm | 2017 |