If a customer’s payment is a larger amount than their total past due amount, this results in a negative balance. The unapplied portion of the payment will also be recorded:

In the example above, the customer has a $40.00 credit which resulted from an overpayment. The $40.00 in Unapplied payments is displayed. If a new invoice is posted for this account, the system will automatically apply the Unapplied amount to the new invoice and update the customer’s Invoice Balance Due accordingly.