Why is Apple's 6s mobile phone suddenly unable to send and receive text messages? I haven't responded for a long time.

Possible reasons and solutions for not sending short messages;

1. Signal reason

2. Owe the phone bill

3. SMS center numbers are inconsistent

4. Manage applications-all address books, and clear cache and data.

5. The address book/contact person is prohibited from starting.

6. Remove the battery and restart it.

7. Put the SIM card on another mobile phone for testing.

8. Use third-party communication software

9. Restore factory settings

10. Brush the machine, preferably with the official ROM.