New mobile phone and card, can't send text messages?

Dear, if the mobile phone can receive short messages, but can't send them, it depends on whether the mobile phone can send them to one user or everyone. If they can't send it, it's usually that the number of the SMS center is wrong or missing. You can call customer service and ask what the center number is. If it can't be sent to only one user, it may be the fault of the other party, or you can change your mobile phone to test whether it can be sent.