ST WiFi Calling saves roaming charges for calls to any Hong Kong numbers and for receiving calls from anywhere in the world.

The other party of the call does not have to be a SmarTone subscriber nor does he need to install the ST WiFi Calling app.

What’s more, when you are in Hong Kong and places where mobile signal is weak or suffers from interference, you can still make and receive calls with ST WiFi Calling and stay fully connected.
 
Features:
• Use your own mobile number so your receiving party can see your usual caller ID
• Voicemail together with alerts for any missed calls
• Supports call waiting and lets you keep your usual connecting tone
• Shares your handset’s phone book for easy contact management
• Support Dual SIM and eSIM
• Simple User Flow: Connect to WiFi, then open the "ST WiFi Calling" app and keep it running in the background to call out or receive calls
 
Remarks:
• ST WiFi Calling is available exclusively to SmarTone customers of designated service plans. Please visit smartone.com/STWiFiCalling/en for details
• The use of WiFi may incur charges levied by third party WiFi service providers.
• Outgoing calls to non-Hong Kong phone numbers will incur applicable IDD charges
• Compatible with designated smartphones running Android5.0 or above
• Download, usage and content update of this service will incur data (including local and roaming) which will be deducted from SmarTone’s relevant subscribed service plans or charged at the applicable thereafter fee. For customers without a data plan, standard data charges will apply