We use the unrealized tax option. The sales tax collected report shows the customer's payment number in lieu of the sales invoice number. Some customer checks will pay for 50 invoices and we have no idea which invoices the sales tax lines are referencing. We are currently hand writing in the invoice numbers on each report to have on file in case of sales tax audits. We have been through a couple of sales tax audits and they randomly choose lines and ask to see those invoices, but we don't know what they belong to.