Common accounts payable errors
Accounts payable teams process a high volume of invoices under time pressure. Small errors pass through because each payment looks reasonable on its own. The pattern only shows when you look at the payment history as a whole. This article covers the errors worth looking for and a monthly check to find them.
Duplicate payments
A duplicate payment happens when the same invoice is paid twice. The causes are ordinary. Corpay's guide to duplicate payments lists several:
- Invoice numbers mistyped or transposed at entry
- The same supplier set up under more than one record
- Invoices arriving by email, portal and mail, then entered more than once
- A corrected invoice paid alongside the original
- No purchase order to act as a second reference
Exact-match checks miss near-duplicates, such as an invoice number with an added letter. A check that compares supplier, amount and date catches more.
Credits that sit unused
Suppliers issue credit memos for returns, price corrections and service failures. If nobody applies them, the credit stays open in the supplier's account while you keep paying full invoices. Pull a statement from each large supplier twice a year and compare it with your ledger. Open credits show up quickly.
Payments without a matching receipt
Where a purchase order exists, the invoice should agree with the order and the receipt. This is a three-way match. Errors appear when the match is overridden to meet a due date, or when the receipt was never recorded. An invoice for goods that did not arrive is still an unpaid obligation in your records, which is a control gap even when the goods eventually show up.
Vendor master file problems
The vendor master file is the list of suppliers your system will pay. Common faults include:
- Duplicate supplier records with slightly different names
- Inactive suppliers that remain payable
- Bank details changed without a second person confirming the change
- Missing or inconsistent tax identification details [VERIFY: tax reporting requirements for supplier payments in your jurisdiction]
Clean-up here prevents several other errors. It is also a fraud control.
Pricing and terms that differ from the contract
An invoice may carry a price higher than the agreed one, or ignore an early-payment discount that you earned. Nobody notices if the invoice total looks familiar. Link the key contract terms to the supplier record so approvers can see them. Our article on common supplier contract errors goes deeper on this.
A monthly check you can run
- Export the last twelve months of payments with supplier, invoice number, date and amount.
- Sort by supplier, then by amount. Look for repeated amounts within a short period.
- Strip spaces, dashes and leading zeros from invoice numbers and compare again.
- List suppliers with more than one record, comparing names, addresses and bank details.
- Request statements from your five largest suppliers and reconcile them to your ledger.
- List open credit memos and decide who will apply or request payment for each.
- Check that the person who enters invoices does not also release payments.
- Record every finding, the amount, the cause and the owner who will fix it.
The step that matters most is the last one. A finding without a cause tends to come back.
Where a review helps
Your own check works for recent activity. A recovery audit looks further back and across the whole payment history, which takes time most finance teams do not have. The accounts payable audit category covers this kind of review. A partner firm in our network asks for the vendor payment history, selected invoices with supporting data and a list of issues you already know about.
Corpay's guide describes recovery audits as a backstop, not the primary defense, and that is a fair way to think about them. Fix the controls first. Use a review for what got through.
When you are ready, request a professional and describe what you have found so far.
Sources
Tell us what you need reviewed. We match you by hand with an independent partner firm. You keep your existing vendors.Find out what you are overpaying.