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.