Is the SMS valid for 24 hours or 48 hours?

Take China Mobile as an example, SMS is usually valid for 48 hours.

SMS will be stored in the system for 48 hours. If the phone is turned off or stopped, the system will keep the SMS for 48 hours. If you turn on your phone or receive a cell phone signal within 48 hours, the system will push the SMS to your cell phone. If it exceeds 48 hours, it cannot be received after the deadline, and the short message cannot be retrieved.

In addition, the SMS fee will be deducted only when the mobile phone receives the SMS, and the SMS that has not been received for more than 48 hours will not be deducted.