When PO items go through QC and are rejected, the system keeps track of inventory automagically. When a purchased item has gone directly into inventory and then has to be returned to the vendor for some reason, we do a negative PO receipt... except if the invoice has been paid already, in which case we get confused.  
 
Once the invoice is paid the PO closes. Should we reopen the PO and process the negative receipt? Does that put a negative receipt into the RNI report? Is that the right thing to do? Sometimes the return is for credit, but other times it is a return for rework. How should rework be handled?
 
It appear that we have been very inconsistent with this in the past. I'm rewriting the purchasing process documents and would like to settle on the best way to handle returns and write it right into the process.