Why can't the SIM card send short messages?

If there is no phone bill (or the phone bill is less than 10 yuan), you can't send text messages. . . Have you tried it on another mobile phone? If there is (and it can't be sent), there is definitely no phone bill (or the phone bill is less than 10 yuan). It is not excluded that the card has expired. . If you try someone else's card (and you can send text messages), the number of the SMS center has been changed. Solution: Call customer service (don't look at this), ask the number of the local SMS center, and then send it back. . .