Why can’t my iPhone 4s send messages?

If your mobile phone cannot send text messages, you can try to restart or change the mobile phone for testing, and check whether the following conditions exist:

1. The SMS center number is set incorrectly, please re-enter it. Correct SMS center number;

2. No signal or low battery;

3. The system is busy due to peak SMS sending volume during holidays. It is recommended that you try again later or Avoid sending peak periods;

4. The sending format is incorrect. If sending a text message to a PHS user, the area code must be added before the number;

5. The text message sending time exceeds 24 hours;

6. The mobile phone has blocked the text message sending function;

7. Being included in the SMS blacklist;

8. The number balance is insufficient;

9. The SMS inbox and sending box are full.

If the above reasons still cannot be solved, you can contact the local customer service or go to the business hall to confirm whether the SMS function is enabled and let the staff handle it.