The Suppliers Your AP Team Knows Too Well.
3 min
By: Daniel Shore
When I was running AP, there were always a few suppliers my team knew a little too well. Not necessarily the biggest suppliers. The troublesome ones.
The same invoice errors would show up again and again. Missing PO information. Pricing discrepancies. Incorrect quantities. Payment-status questions. AP would fix the problem, get the invoice moving, and go on to the next one. Then the supplier would do it again.
It reminded me of parenting. If your kids leave their shoes in the hallway and you pick them up every night, eventually they learn something: apparently, that’s where the shoes belong.
We become so good at accommodating bad behavior that there is little reason for the behavior to change.
Accounts payable can unintentionally train suppliers the same way. We become so good at accommodating bad behavior that there is little reason for the behavior to change.
That matters because supplier friction is expensive. Ardent Partners reported that AP organizations spent 22% of staff time handling supplier inquiries in its 2024 benchmark research. The average invoice exception rate was 14%. Those are two different measures, but they point to the same operating problem: a meaningful amount of AP capacity is still consumed by transactions that do not move cleanly.
Many supplier performance scorecards are missing a question AP can help answer:
How much work does this supplier create?
The Supplier Friction Score
Start with measures you can pull from your existing process, then add a simple weighting.
You do not need a sophisticated formula to get started. Rank suppliers across these dimensions. Even a simple high, medium, or low score will probably expose something traditional supplier reporting does not.
Your highest-volume supplier may not be your highest-friction supplier. A moderate-volume supplier whose invoices regularly need investigation can consume more AP time than a much larger supplier whose invoices flow through cleanly. And a recurring exception on a high-value invoice deserves attention for another reason: while AP works the issue, the supplier is waiting for cash, and both sides may lose an opportunity to settle on better terms.
That difference rarely appears on a procurement scorecard.
The Number I’d Watch Closest
Of the measures above, I would pay particular attention to the repeat exception rate. The point of a supplier-friction program is to reduce the problems AP has to fix in the first place.
I like to track the dollar value behind those repeat issues. Ten small exceptions and ten exceptions holding up substantial invoices create different priorities. If an early payment discount was available but the invoice sat in a queue until the window closed, record that too. You do not need to put a dollar figure on every inconvenience. You do want to recognize when a familiar workaround is costing real money.
Find the Source of Friction
Take your ten highest-friction suppliers and identify the primary cause of the work.
The goal is to determine who can change the pattern.
That distinction also fits the supplier questions we are building into the 2026 AP Innovation & AI Benchmark: how much exception activity originates in recurring supplier issues, and which supplier interactions consume the most AP time. These measures matter because traditional invoice metrics do not capture all the work surrounding a transaction—or how long an invoice waits while that work gets done.
Stop Rewarding the Workaround
This is where I come back to the shoes. AP teams are extraordinarily resourceful. Give them a bad invoice and they will usually find a way to get it paid. That is a huge strength.
But there is a downside. We become the workaround.
Once a pattern becomes visible, challenge it:
“We’ve had this issue on 17 invoices during the past 90 days. Here’s what happened, the work it created, and the invoice value held up while we resolved it. Here’s what needs to change.”
Bring that finding to your purchasing partners and put it in the next supplier business review. Find the person on the supplier’s billing team who can help fix the cause.
That is a very different conversation from “Can you resend invoice 34872?”
One fixes an invoice. The other fixes a relationship.
Try It With Your Top 20
You do not need a six-month transformation project. Pull 90 days of supplier activity. Take your 20 largest or most active suppliers. Add exceptions, repeat issues, AP touches, inquiries, and the value and age of invoices held up. Where early payment discounts apply, note which ones were missed because an invoice could not be approved in time. Then rank the suppliers.
The result may tell you more about where AP productivity and payment opportunity are disappearing than another industry cost-per-invoice benchmark. More importantly, it gives you a place to start.
