1. Credit card is not fully paid off in the early stage: if the monthly credit card bill can be paid off in one lump sum, there will be no other interest expenses, and many people can't pay off all of it, but only the minimum amount or installments. These two repayment methods can only ensure that they are not overdue, but they will generate interest charges, which will be included in the next bill arrears.

2. The previous credit card is overdue: If the previous credit card fails to pay the minimum repayment amount, or fails to pay within the prescribed time limit, the interest on the outstanding debt will be calculated in full from the date of consumption, and the penalty will be charged, so the next credit card bill is likely to be thousands more than the actual one.

3. Credit card annual fee deduction: the annual fee of credit card is charged once a year, and it will be directly deducted from the quota if the exemption conditions are not met. For example, many high-end credit card annual fees cannot be exempted, and the deducted annual fees are included in the next bill, which will also lead to thousands more credit card bills than the actual ones.