Verifying an invoice is three questions, and asking them in the right order saves a great deal of effort, because each is cheaper to answer than the one after it. Organisations that start with the expensive question, whether the invoice agrees with the order, end up investigating documents that should never have entered the process at all.
Is it ours
Addressed to our legal entity, from a supplier we have, for something we plausibly buy. This is the cheapest check and it catches invoices meant for another organisation, and invoices from a supplier you have never used, which is the shape of the most common payables fraud. It takes seconds and it should come first.
Is it new
Has this supplier and invoice number combination been seen before, and is there anything else for the same supplier, similar amount and near date. The first catches accidental duplicates; the second catches reissues with a new number, which the first misses entirely. Both are cheap and both prevent a payment that is much harder to recover afterwards.
Does it agree
Comparison against the purchase order and the goods receipt within tolerance, at line level. This is the expensive question because it involves other documents and sometimes other people, and it is worth asking last, on invoices that have already passed the two cheap checks.
Questions people ask about invoice verification
Should verification block payment?
The first two questions should block if answered badly. The third produces an exception to be resolved rather than a rejection.
Can this be automated?
Largely. All three are rule-based given the right data, and automating them frees attention for the judgement cases.
What about invoices with no order?
The third question cannot be asked, so verification stops at the first two and approval falls to whoever authorised the spend.