When you apply for a credit card. According to the public information of the postal savings bank of the inquiring country, it is not necessary to provide proof of work when handling the savings card. Only when you apply for a credit card will you be asked to provide proof of work or income to evaluate your credit status. This is because credit cards need to be used within a certain credit limit, and banks need to determine the credit limit and credit card issuance by evaluating personal income and credit status. But for a savings card, you only need to provide personal identification and a certain amount of deposit.