Four days.

According to the query on Lutu.com, we learned that postal credit cards have a grace period, the longest is before 17:00 pm on the fourth day of repayment, and the shortest is three days. If the debt is not paid off and the minimum payment is not paid before 17:00, the overdue record will be uploaded to the credit investigation system. In addition to affecting personal credit, cardholders also need to pay late fees and overdue interest. The standard for charging late payment fees is 5% of the unpaid portion of the minimum repayment amount, and interest is calculated at a daily interest rate of 0.5% until the cardholder pays off the balance.