Why can't my mobile phone send short messages to Unicom?

According to the situation you described, the reason why you can't send a short message and how to deal with it: 1, the number of the mobile phone short message center is set, so it is recommended to check whether it is set correctly; 2. There is no signal or the battery of the mobile phone is insufficient; 3. The system is busy during the peak period of holiday SMS sending, so it is suggested to try again later or avoid the peak period of sending; 4. The sending format is incorrect. If you send a short message to PHS users, you need to add the area code before the number; 5. The SMS inbox and sending box are full; 6. Try to restart or replace the mobile phone for testing; 7. Query whether the SMS function is turned on. If the above situation has not been solved, it is suggested that you can contact the local manual customer service for handling.