There are three main principles to determine the credit card limit:
1. Whether it can be returned on time;
2. the needs of cardholders;
3. The former takes precedence over the latter;
For wage earners who don't have much extra income, the appropriate credit card amount is roughly = monthly disposable income ÷ minimum repayment ratio, while monthly disposable income = monthly income (after tax)-basic living expenses-loan repayment;
At present, the minimum repayment ratio of credit cards is basically 1%, so the maximum amount that banks can grant should be 1 times of the monthly disposable income, which can ensure that the monthly disposable income is at least enough to repay the minimum repayment of credit card arrears.