To get this benefit, you must first determine that you are a 4G user and your mobile phone supports the VoLTE function.
To promote the VoLTE feature, China Mobile launched a free trial of VoLTE HD voice calls during the period from January 1, April 1-6. Users who have not yet activated this feature can receive a 500-minute call duration each month, expired automatically at the end of the month.
If you want to continue the next month, you can apply for the package again, but only before January 1, June 30.
Note that the free 500-minute call is limited to VoLTE, and the call is still charged for 2G/3G. If the 500-minute call time is used up, the excess duration will be charged according to the normal standard.
Of course, you still need mobile phone support to call VoLTE. Currently, this function is supported by iPhone 6, iPhone 6 Plus, iPhone 6 S, iPhone 6 s Plus, and many Android models, for specific handling methods and supported models, see China Mobile's online business office.
500-minute free call address: http://service.js.10086.cn/GQYYYW.html