We use the Service Receivable module for most of our volume of invoicing and we require many many prepayments and down payments.

We currently create an invoice in 11-2 for the prepayment/down payment that is posted to a liability account for Client Prepayments.  We receive the prepayment and this invoice is paid off.

After the work order is completed, (sometimes the same day and sometimes many weeks later), we create a new invoice for the total amount to bill.  We then need to find out if a prepayment was processed and apply it to that final invoice before we mail the invoice.  As we do more and more of this, it is getting complicated to try to match up each prepayment with each invoice.  We have missed a few and we do not like getting calls from clients asking about a prepayment that should have been applied.  Does anyone know it there is a simpler method of handling prepayments?