In a larger business, a goods received note (GRN) is generated whenever a delivery is made to the business. The GRN details what goods and quantities have been received and when. A copy of the GRN is sent to the accounts department to enable them to match it to the purchase order (that would have been raised when the goods were originally ordered from the supplier).
When the invoice is received, this is matched to the purchase order and GRN. Only if the details on all three match up, is the invoice paid.