What the international code for Cameroon to call? Dial code number to open phone call in Cameroon is ( 00237 ) or ( +237 ) in order to make international phone calls between Cameroon and all countries of the world to unlock phone with more additional details and informations about Cameroon country whereby each country is distinguished by a special telephone number, where the caller write the Republic of Cameroon dial area code to opening sim card telephone line mobile or landline then the phone number.