Dynamics GP has long had a challenge when it comes to paying P.O. invoices. If an invoice comes in to AP, AP may process it without realizing that there was an outstanding P.O. or Receipt to match the invoice against. This often orphans P.O. Receipts and can duplicate expenses.
We’ve dealt with cleaning this up before.
The GP team has tackled this with a new GP 2015 feature. You turn it on in Payables Setup, then AP transactions check for the possibility of open P.O.’s for the vendor selected. If an AP vendor has an open P.O., saving or posting the transaction will throw a warning. What’s nice is that the warning options include continuing with the transaction or opening a P.O. navigation list for that vendor making it easy to then flow into processing a PO transaction.