What the international code for Laos to call? Dial code number to open phone call in Laos is ( 00856 ) or ( +856 ) in order to make international phone calls between Laos and all countries of the world to unlock phone with more additional details and informations about Laos country whereby each country is distinguished by a special telephone number, where the caller write the Lao People's Democratic Republic dial area code to opening sim card telephone line mobile or landline then the phone number.