How to charge for changing the package at the beginning of the mobile month?

The charges for changing the package at the beginning of the mobile month are as follows:

According to the query of China Mobile official website, there is no charge for changing the package at the beginning of the mobile month, and mobile users can change the package halfway if they meet the conditions for changing the package. The changed package will take effect in the next month, and will be charged according to the new package tariff standard, and the old package will still be charged in the same month. If the changed package needs to be charged separately, it needs to be paid as required, which is more necessary than the activity of saving phone bills and sending mobile phones, and it needs to be prepaid as required to participate in the activity. This prepaid fee belongs to the prepaid fee for participating in this activity and has nothing to do with the change of package fee.