It's possible that your girlfriend didn't pay off her credit card bill last month, so she generated cyclic interest. The revolving interest of China Merchants Bank is charged when you use revolving credit to repay loans or use cash borrowed in advance. If all the consumption funds are paid off in full before the due repayment date of the current billing cycle, you can enjoy the interest-free period by swiping your card without generating cyclic interest; Failure to pay off all the bills in the current period on time is regarded as the use of revolving credit.

That is to say, from the bookkeeping date (usually the day after consumption), interest will be charged on all consumption in the current period, with a daily interest rate of five ten thousandths until you pay it off in full. If you use the cash advance function, you cannot enjoy the interest-free period of cash advance. Interest will be calculated from the date of cash withdrawal, with a daily interest rate of 0.5 ‰, and compound interest will be calculated monthly until it is paid off.

To sum up, it is best for the landlord and his girlfriend to pay off the current credit card bill as soon as possible to avoid the accumulation of circulating interest in the next period. The landlord can consult the customer service of China Merchants Bank if he has any questions!