I just changed my China Unicom card, why can’t I send text messages?

If China Unicom mobile phone users cannot send text messages, they can try to restart or change their mobile phones for testing, and check whether the following conditions exist:

1. The SMS center number is set incorrectly, please try again. Enter the correct SMS center number;

2. There is no signal or the mobile phone battery is low;

3. The system is busy due to peak SMS sending volume during holidays. It is recommended to 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.