We have an overpayment of an expense to an employee. It was marked as billable and was actually billed to the customer. Now, the employee gave a check to the company for the overpaid amount. This should also reduce the subsequent amount to be billed to the customer. Is there a way to have a negative billable expense without including it in other positive billable transactions or without using a regular item (instead of billable expense sublist) on the invoice?