What are the differences between SmartIDD and 1638 IDD service?
SmartIDD service is available solely for SmarTone-Vodafone customers. It allows customers to make IDD calls in both Hong Kong and roaming countries via handsets. For 1638 IDD service, anyone may apply and make IDD calls via any kind of phones (e.g. residential phones, office telephones, and mobile phones on other networks) or facsimile machines ; but the IDD calls can only be made from Hong Kong. A HK$1,000 IDD deposit for these services will be waived for monthly bills paid through autopay service with VISA, MasterCard, American Express Card or Diners Club Card.
