Why are you prompted to open the SMS service when you make a phone call?

1. There are generally four reasons for prompting the other party to open the SMS service when calling: power off, no signal from the other party in the service coverage area, flight mode setting, and you are blacklisted. In this case, the mobile phone will prompt to open the SMS service after dialing once.

2. SMS calling service is a service provided by mobile company, and the cost is 1 yuan/month.

3. When the other party turns off the phone and can't get through, you will tell the other party to start the SMS service. When he opens his mobile phone, he will receive your call record: XXXXXXX users call you at XXXXXXX time, please reply in time.

4. If it is blacked out, it will prompt that the other party has turned off, the other party has turned off, and the dialed number does not exist, and the SMS service will also be called.