An invoice can differ from a purchase order for several reasons: an approved price change, a partial shipment, a substitute, freight, a billing error or a change that nobody authorized. The mismatch is a question to investigate, not an instruction to edit the PO until it matches the bill.
Start with the original request, the buyer-approved changes and the physical receipt. Keep all three visible alongside the invoice.
Identify the kind of difference
| Difference | Check first | Owner of the next decision |
|---|---|---|
| Price | Original price, supplier proposal and approval | Authorized buyer or finance reviewer |
| Quantity | Ordered, received, still due and previously billed | Receiver and buyer, with AP checking billing |
| Substitute | Actual item, pack conversion, suitability and acceptance | Buyer and relevant kitchen/quality owner |
| Freight or surcharge | Agreed charge and allocation, including other invoices | Buyer and finance |
| Credit | Credit requested, issued and applied | Buyer follows up; finance verifies posting |
| Duplicate | Supplier, invoice identity, amount and prior entries |