Accounts payable invoice processing is everything that happens to a supplier invoice between arriving and being posted, and it is worth defining by its end state rather than its steps. An invoice is ready to post when four things are true: it is genuinely ours, somebody with authority agreed to the spend, what it claims was actually received or performed, and it is coded to the right account and period. Every step in processing exists to establish one of those four. Thinking about it that way makes it much easier to see which steps are load-bearing and which are habit, and this page walks through the four with the checks that establish each.
It is ours, and it is not a duplicate
Supplier, invoice number and amount, checked against what is already recorded. Duplicate payment is one of the most common and most recoverable payables losses, and it is prevented at entry by a uniqueness check rather than found later by an auditor.
Somebody agreed to it, and something arrived
Approval establishes authority; matching establishes receipt. Where there is no order and no receipt, the person who commissioned the work confirms both, and that confirmation should be recorded as deliberately as a goods receipt would be.
It is coded to the right account and the right period
The period is the one everybody forgets until the close. An invoice dated before the cut-off for goods received before the cut-off belongs in the period, whenever it happened to arrive. That judgement is why unapproved invoices at the cut-off become accruals rather than next month's problem.
Questions people ask about accounts payable invoice processing
What is the difference between processing and the process?
None worth arguing about. Processing tends to describe the day-to-day handling and process the route it follows. Both are answered by the same four conditions above.
How do we prevent duplicate invoices?
A uniqueness check on supplier and invoice number at entry, and a rule that credit notes are recorded rather than netted off by hand. Most duplicates arrive because a supplier resent a copy and somebody helpful entered it.
Should invoices be posted before approval?
Posting an unapproved invoice records a liability you have not yet agreed. Some teams do it to keep the ledger complete and mark it clearly; what matters is that the state is visible either way.