To take advantage of the interest free period on credit cards you must pay the minimum balance each and every month, and within the payment due date. There is nothing stopping you from making extra payments. The interest free period starts the day after the last statement and is up to the payment due date. Cash withdrawals, balance transfers and credit card cheques are usually excluded from the interest free period. If they are excluded you will pay an interest charge from the day you withdraw cash or use credit card cheques.