Why is the money deposited in postal savings card automatically transferred to the online merchant bank card?

Automatic fee deduction. It is because you have opened the function of automatic deduction of Alipay. After the deposit amount is entered, the money you set will be automatically deducted, so it is automatically deducted. Postal savings in China can be traced back to the postal savings business started in 19 19, which has a history of one hundred years. In March 2007, on the basis of reforming the original postal savings management system.