It may be an installment fee. Handling credit card installment payment of CCB basically requires a handling fee, but there is no interest. Different installment types, different installments, different amounts, and different commission rates. If 200 yuan is paid more every month, the commission will be paid in installments. I suggest that you can check the bill details of each issue through WeChat Bank, mobile banking or online banking. If it is really a handling fee, the word "handling fee" will be clearly recorded on the bill.