AR actually handles prepayments quite well, as opposed to AP, which really doesn't handle them at all. If the cash receipt was posted to the customer account in June it should appear as a PP invoice type and show a credit balance on the aging as well as on the trial balance. Have you looked at the transactions as they are shown on the invoices tab in customer maintenance? Your description makes it sound as if the invoice was actually already posted before the cash receipts entry was posted, which would explain why a PP record wasn't created.