Chapter 7: Q3E. (page 345)
Z-Mart uses the perpetual inventory system and allows customers to use the Z-Mart store credit card in charging purchases. Z-Mart assesses a per-month interest fee for any unpaid balance on its store credit card at each month-end.
Apr. 30 Z-Mart sold merchandise for \(1,000 (that had cost \)650) and accepted the customer's Z-Mart store credit card.
May 31 Z-Mart recorded $4 of interest earned from its store credit card as of this month-end.
Short Answer
An unpaid balance on a credit card is the balance amount that reflects a non-payment by itsholder to the bank. Regular interest is applied to the unpaid balance to pay the outstanding amount earliest.