Legal analysis: the credit card is 30,000 yuan, and the overdue payment fee and overdue interest will be charged if it is overdue 1 year. The handling fee for overdue payment is charged at 5% of the unpaid amount, and interest is charged at 0.5 ‰ of the full bill every day, with compound interest on a monthly basis. The specific calculation method is as follows:

30,000 yuan overdue for one year is 30,000 * 5% = 1.500 yuan; Because of monthly compound interest, the overdue interest in the first month is 30000*0.05%*30=450, the interest in the second month is (30000+450)*0.05%*30=456.75, and the interest in the third month is (30000+456.75) * 0.05.

Legal basis: China Bank Card Industry Self-discipline Convention.

Article 14 Member units should strive to improve the service quality of credit cards, provide humanized services for cardholders, and advocate card issuers to establish "tolerance service and time-sensitive service" for credit card repayment or to give interest relief to the repaid part of credit card overdraft during the interest-free repayment period:

(1) When providing "time-tolerant service" to cardholders, member units shall provide cardholders with a repayment grace period of a certain period, and the repayment grace period shall be at least 3 days from the due repayment date; If the cardholder repays within the repayment grace period, it is deemed that the cardholder repays on time.

(2) Member units provide "tolerance service" for cardholders. If the cardholder fails to repay in full in the current period, and the unpaid part in the account after the due repayment date is less than or equal to a certain amount (at least equivalent to RMB 10 yuan), it is deemed that the cardholder has repaid in full.

Article 15 When the cardholder's repayment amount is lower than the minimum repayment amount before the due repayment date (inclusive), the member unit may charge a late fee. The late payment fee shall not exceed the national standard.