Invoice fraud doesn’t usually announce itself. It arrives looking like routine business — a familiar supplier name, a plausible amount, an invoice that matches the format your team sees every week. That’s exactly why it works.
Here are five red flags that consistently show up in confirmed invoice fraud cases, and why they’re easy to miss without systematic checks in place.
1. A bank account change with no clear paper trail
The single most common vector for invoice fraud is a changed bank account. A supplier’s payment details shift, often via an email that looks legitimate, and the change goes through without independent verification. Any account change should trigger a re-validation against trusted banking data — not just a reply-to-confirm email, which can be spoofed just as easily as the original request.
2. Urgency and pressure to bypass normal process
Fraudulent invoices are frequently paired with urgency: “this needs to go out today,” “the supplier is threatening to pause deliveries,” or a request routed around the usual approver. Genuine urgency happens, but it should never be a reason to skip verification — it should be a reason to verify faster.
3. Supplier details that don’t match your KYB records
A registered business name that’s slightly different, a tax ID that doesn’t resolve, or an entity that doesn’t appear in the registry you validated at onboarding are all signals worth stopping for. KYB checks aren’t a one-time gate — they’re a reference point every subsequent invoice should be checked against.
4. Round numbers and inconsistent formatting
Genuine invoices tend to have specific, itemized amounts. Fraudulent invoices are more often round numbers, or formatted slightly differently from a supplier’s usual template. Individually, this is weak evidence. Combined with other flags, it’s worth a second look.
5. No independent record of the underlying purchase order
An invoice with no corresponding purchase order, or one linked to a PO that’s already been fully invoiced, is one of the easiest checks to automate — and one of the most commonly skipped under time pressure.
The common thread
None of these red flags are hard to catch individually. The problem is catching all of them, consistently, on every invoice, without adding hours to your AP cycle. That’s the case for building verification into the payment workflow itself, rather than relying on a reviewer to remember to check.