Fraud in payables is not exotic. It arrives in three recognisable shapes, and the defences against each are procedural rather than technical. Knowing the shapes is most of the defence, because all three depend on somebody in a hurry processing something that looked ordinary, and all three are stopped by a check that takes a minute.
The false invoice
An invoice from a supplier you do not use, for something plausible, at an amount below whatever people scrutinise. It works because it looks like every other invoice and because somebody assumes a colleague ordered it. The defence is the first validation check: does this supplier exist in our records, and if not, why is this being processed.
The diverted payment
A convincing request to change a supplier's bank details, often referencing a real invoice and a real contact. This is the largest by value because it redirects payments you genuinely owe. The defence is entirely procedural: verify using contact details you already hold, never those in the request, with somebody other than the person who received it, and record the verification.
The internal supplier
A supplier record created by somebody inside the organisation, billing for services that are never delivered. It survives because supplier creation is often unreviewed and because the invoices are small and regular. The defence is separating supplier maintenance from payment release, and reviewing new and amended supplier records periodically from outside the process.
Questions people ask about accounts payable fraud
What is the single most valuable control?
Verifying bank detail changes through a channel you already hold. It stops the shape that costs the most, and it costs a phone call.
Does software prevent fraud?
It enforces the checks and records who did what. The judgement, particularly on a convincing bank detail request, stays human.
How would we notice the internal supplier case?
A periodic review of supplier records created or amended, performed by somebody outside payables, plus statement reconciliation on unfamiliar names.