What the international code for Brunei Darussalam to call? Dial code number to open phone call in Brunei Darussalam is ( 00673 ) or ( +673 ) in order to make international phone calls between Brunei Darussalam and all countries of the world to unlock phone with more additional details and informations about Brunei Darussalam country whereby each country is distinguished by a special telephone number, where the caller write the Brunei Darussalam dial area code to opening sim card telephone line mobile or landline then the phone number.