Your buyer negotiated a six-week promo price. It's week forty and that price is still on the invoice. Nobody chose that. The deal ended, the billing didn't, and nothing between the signed agreement and the ERP was ever going to notice.
Review was never built to catch this
Your AP team checks a few hundred lines a month. You have thousands of SKUs across dozens of vendors. That isn't auditing, it's sampling, and an expired promo price is the single best thing you could design to survive a sample. Real price. Real agreement. Real SKU. The only thing wrong with it is the date.
And the date is the one fact your reviewer can't see. The agreement is a signed PDF or an email thread with the vendor. The invoice is in the ERP. Nothing joins the two, so nothing flags the gap. This is not a rounding problem: auditors at The Audit Partnership put the overpayments slipping past ERP controls at roughly $3.5 million for every $1 billion in spend.
Our agents start where review can't: the date
Each agent reads the governing agreement first, so it knows the price and exactly how long that price was allowed to live. Then it walks your invoice lines and waits for the day the number should have dropped. When it doesn't drop, that's a finding.
Once you're matching invoices to agreements instead of to memory, the rest comes free. The allowance you earned and never deducted. The chargeback that quietly disappeared. The same line paid twice under two PO references. None of it is clever fraud. It's a new product flavor nobody added to the existing promo contract, or an allowance keyed per-unit when the deal said per-case. Boring, invisible, and running across every vendor you have at once.
In retail, recovery is a phone call
This is why the packaging matters more here than in most verticals. You're not making a quiet journal entry on your own side. You're calling a vendor you'll negotiate with again next quarter, and that call goes very differently depending on what you open with.
So every finding arrives as a case, not a flag: the agreement page, the invoice line, and the date range that puts them in conflict. You're not opening with a suspicion. You're opening with their own signature.
Try it on one vendor before you talk to us
You can test whether you have this problem in an afternoon, with a spreadsheet and no vendor conversation at all. Pick your three highest-volume vendors. List every promotion that ended in the last twelve months, with its end date and its promo price. Pull the invoice lines for those SKUs for the ninety days after each end date, and compare the unit price to what it should have reverted to. If nothing comes back, you're in better shape than most retailers. Most people find something in the first vendor.
The reason it survives is that it's beneath everyone's attention
Any one of these lines is too small to chase. That's the whole trap. Nobody escalates a $40 discrepancy, so a thousand $40 discrepancies get to live, quarter after quarter. Read the ledger all at once and the trap inverts: the pile that was never worth assembling by hand becomes a credit worth collecting.
The money was never hidden. It was filed under "not worth it," one line at a time.