What must a cardholder do to avoid paying interest on credit card purchases?

To avoid paying interest on credit card purchases, a cardholder must pay the entire balance in full and on time every month. This practice is critical because credit cards typically have a grace period, which allows cardholders to avoid interest charges on new purchases if the previous month's balance is fully paid off by the due date. When the full balance is paid, no interest accrues on that amount, meaning the cardholder effectively uses the card without incurring any additional costs beyond their purchases.

Making partial payments or paying only the minimum does not eliminate interest charges, as interest will be calculated on the remaining balance. Similarly, waiting for a promotional 0% interest period might avoid interest temporarily, but it does not address the fundamental strategy of paying off the full balance each month. Thus, consistently paying the balance in full and on time is the most effective way to manage credit card debt and avoid interest fees.