Credit card interest is calculated based on the amount owed and the interest rate, rather than the time or method of early repayment. When repaying early, it can indeed reduce future interest expenses because the outstanding amount is reduced. of the principal balance, which means less interest charges will be paid. A credit card is a payment instrument issued by a bank or credit card company to individuals or businesses. It allows cardholders to consume first and pay later, and repay interest-free within a certain period. Credit cards have the functions of consumption payment, credit loan, transfer settlement, deposit and withdrawal Cash and other functions provide consumers with great convenience and consumption flexibility. Credit cards enable consumers to shop without cash, increasing consumption flexibility.