If you are in a destination that only supports VoLTE Roaming Service (such as USA where there’s no 2G/3G network coverage), you will need to enable VoLTE Roaming Service to make and receive calls; The system will prioritise the use of VoLTE Roaming Service once you have enabled it. VoLTE Roaming Service enables faster connection and clearer voice calls.

You have to meet all of the following criteria:
1. Use a VoLTE-compatible handset and software
2. Enable VoLTE function on the handset
3. Enable IDD & Roaming
4. Connect to a VoLTE-supported mobile operator in designated VoLTE-supported destinations

Yes, simply enable VoLTE in your phone settings (To learn how to enable VoLTE roaming service, please click here or refer to the user manual of your smartphone model)

The charges for using VoLTE Roaming Service are the same as standard roaming call charges (Please click here for details). VoLTE roaming calls are charged on a per-minute basis, call duration is rounded up to full charge units for computation purposes.

No.

You can use VoLTE roaming service in Mainland, Japan, USA and other designated popular destinations with VoLTE coverage. (Please click here for details).

The availability of VoLTE roaming service depends on whether the local mobile operator has VoLTE network coverage in the area. If you are in an area without VoLTE network coverage, your network will be automatically switched to 2G/3G, and you cannot use VoLTE roaming service.