Entering Purchase Orders with a plus or minus percentage qty allowed from the supplier

We have a supplier that provides customs packaging boxes. The qty received is never exact. IS there a way to select a flag to allow for under or over receipts that will close the PO line at the time of the receipt?

Just mark the Receipt line “Received Complete” and that will close the PO line release. But doing so would not allow future receipts against that PO line release.