How does China Telecom Tianyi mobile phone send text messages or make phone calls to Hongkong mobile phones? What about Unicom's mobile phone?

To send text messages or make phone calls to foreign users, it is necessary to open the international long-distance function. You can bring valid documents to the business hall, and you need to pay a deposit from 500 yuan. Cancel the international call function and you can retire.

When sending short messages to users in Hong Kong, Macao and Taiwan and overseas operators, enter "00+ country code+user number" as the receiving number. For example, when sending short messages to users in Hong Kong, enter "00852+ user's mobile phone number" as the receiving number.