What the international code for Hong Kong to call? Dial code number to open phone call in Hong Kong is ( 00852 ) or ( +852 ) in order to make international phone calls between Hong Kong and all countries of the world to unlock phone with more additional details and informations about Hong Kong country whereby each country is distinguished by a special telephone number, where the caller write the Hong Kong Special Administrative Region of China dial area code to opening sim card telephone line mobile or landline then the phone number.