How does Xiaomi change his calling card to send text messages?

Hello, first of all, I need to know if I can send a text message before. If you can send it before, the same number has not been upgraded or restored. Generally, there is something wrong with the SMS function. If you can't send text messages before, it may be related to the settings of your mobile phone.

Reasons for the failure of sending SMS by mobile phone:

1: The SMS center number is set incorrectly. Solution: Call the local Unicom customer service center (dial 100 10) and ask them to send you the number of your local Unicom SMS center. Then set it.

2. The mobile phone is in arrears. Solution: Charge the mobile phone in time.

3. The mobile phone is not in the service area. That is, the mobile phone is roaming, or the mobile phone is in the signal blind area. Some mobile phones can't roam automatically. Solution: Return to the cell phone signal service area in time. If the mobile phone can't roam automatically, handle roaming business in time before leaving the service area next time.

Doing business is free. Only roaming charges will be charged if you use it when roaming. Of course, roaming charges will only be charged for calling, and roaming charges will not be charged for texting and surfing the Internet.