China and South Korea send text messages.

First of all, the other party needs to open an international roaming service, otherwise it can't send and receive short messages normally.

If the other party's mobile phone is also the number of China Mobile or China Unicom,

The short messages you send to the other party are charged 0. 1 yuan each.

The short message sent to you by the other party is charged according to the international roaming fee, and the price may be around 2 yuan.