Iphone5 can't send messages with Unicom card, but it can receive messages. What happened?

The processing method that the mobile phone cannot send short messages is as follows:

1. If the balance is sufficient, it is recommended to change your mobile phone and see if you can send and receive short messages.

2. If you can send and receive short messages, it is suggested that you plug the card back into your mobile phone and send yourself a short message to see if you can receive it.

3. If not, it is recommended to check whether it is a sim card problem.

4. Check whether the number of SMS center is set correctly.

5. Bring the mobile phone card to the local business hall for testing or replacement.