After the credit card is overdue (different banks), a late fee of 5%-6% of the total overdue amount will be charged, and a penalty interest of 0.05% of the total overdue bill will be charged every day.

If the payment is overdue for 30 days, the overdue fine of 5% of the principal of 3,000 yuan is 150 yuan, and the penalty of 0.05% per day is calculated as 45 yuan.

150 overdue fine +45 yuan penalty interest+3,000 overdue principal = 3 195 yuan (calculated as 30 days overdue).