We just sold the manufacturing operations of the company and now are only 2 employees. The person doing  AR, receives the bill from the vendor which is the indicator that the SO can be closed. She then proceeds to invoice the customer. If she happens to miss or lose the invoice, the customer wouldn't be invoiced until someone notices the order is still open (this happened with the other accounting software) but we'd have to research to see if the order is truly open as we have many that remain open for a while.

Since the items are marked as billable, the balance will remain on the Unbilled Costs Report unless I go in and uncheck the billable box.

Sorry if I'm rambling. I'm trying to make sense of this myself and find a way to make sure the customers are being billed, and the SOs and POs are closed.