If you have Concur Intelligence, there is a report under expense processing titled "Missing Receipt Audit". This report may, or may not be useful to you in its current form, as it shows reports with missing receipts and not the line items with the missing receipt. If you, by policy, allow certain types of transactions to flow through without receipts, this report may not be useful to you in its current state, but it could be altered to meet your specific needs.
