Your system already recognizes and posts your invoices, yet your team is still working on them. Even when invoices arrive in a structured format—for example, via Peppol, the international network for electronic invoices—there’s still work to be done. Read why structured invoices don’t eliminate the work.
In Ardent Partners’ report *AP Metrics that Matter in 2025*, 53% of respondents cite invoice exceptions as one of their biggest challenges. The survey polled 212 AP and finance managers. This page defines exceptions in invoice processing and provides a metric for them: work that isn’t itemized separately in your reports. You’ll learn what it costs and how to systematically reduce it.
Exceptions don’t disappear entirely, but you can reduce their number and resolve the rest more quickly. What actually counts as an exception?
What is actually an exception
An exception is an invoice that does not follow the normal process in your workflow, requiring someone on your team to intervene. In AP software, you’ll come across the term “exception” to refer to this type of invoice. The types listed below are similar in one respect: the invoice remains pending until someone intervenes.
– Missing purchase order: The invoice does not match the purchase order because there is no purchase order, and someone is trying to determine who placed the order.
– A price that differs slightly: the invoice remains open until someone checks whether the difference is significant. Differences at the line item level can cancel each other out in the total. Learn more about differences that cancel each other out in the total.
– Partial delivery: The invoice covers more than what was received, so someone needs to decide whether to wait or proceed with a partial shipment.
– Approver is absent: the invoice is ready, but no one is authorized to approve it.
– A payment reminder that comes in as an invoice: it ends up in the same workflow until someone realizes it isn’t a new invoice.
– Invoice addressed to the wrong company: The invoice itself is correct, but it’s not for your company, and someone needs to let the supplier know what’s wrong.
In our experience, an exception costs many times more than an invoice that processes automatically. How can such a minor deviation cost many times more than an invoice that processes normally?
Why an Exception Costs a Multiplier
An exception involves four actions that your report does not list separately: look up, contact, wait, and reassess. Your report does not list “look up,” “contact,” “wait,” and “reassess” separately. If you want to look up an exception, open the ERP system, your email, and the receipt log.
So you have to switch back and forth between those systems before you figure out where things went wrong, and that takes time—even for a single invoice. Then comes the follow-up. An error during goods receipt might end up with someone in accounting who wasn’t involved in that receipt. That person first has to find out who was there, and that extends the turnaround time. Without a designated owner for each type and without an SLA, an exception remains pending until someone responds. If the investigation isn’t documented anywhere, whoever takes over—whether due to a reassignment or illness—has to start from scratch. The investigation is therefore redone, and that takes more time.
When it comes to market reports on exceptions in accounts payable, we rely on a single source: Ardent Partners. Ardent Partners defines an invoice as “touchless” if it is processed straight-through, without human intervention. In *AP Metrics that Matter in 2025*, Ardent Partners reports that, on average, 32.6% of invoices are processed “touchless”—that is, without human intervention—compared to 49.2% among the top-performing group. Ardent Partners classifies as exceptions, among other things, invoices that stand out due to coding errors, missing information, delayed approvals, or a missing purchase order.
In *AP Metrics that Matter in 2025*, Ardent Partners reports that, on average, 14% of invoices result in an exception, compared to 9% for the top-performing group. If you’re monitoring the budget, you’ll want an annual figure. Calculate the annual amount as the number of exceptions per year × the time required for the four tasks × the hourly rate. Time saved is capacity, not a cash savings. As a benchmark: in *AP Metrics that Matter in 2025*, Ardent Partners reports an average cost of $9.40 per processed invoice, compared to $2.78 for the top-performing group. Converted at the ECB exchange rate of October 2, 2026 ($1.1225 per euro), that is approximately 8.37 euros versus approximately 2.48 euros, for illustrative purposes. This is a cost per invoice, not per exception, so do not use it in the formula. Why doesn’t a tool that detects discrepancies take over that analysis?
Detecting a problem is not the same as solving it
A tool that detects discrepancies and places them in a queue simply shifts the work from searching to waiting. The discrepancy itself is not yet resolved. A queue is not a solution; it’s just a neater version of the same problem. If you’re looking for a solution to invoice verification discrepancies, check to see if the tool also handles the investigation.
Resolving an exception involves doing the research that an experienced employee would do: looking up the contract price, reviewing the most recent invoices, checking the receipt history, and pulling up the email conversation—and then proposing a decision. The backlog is a design issue, not a performance issue with your team. Resolving an exception properly is one thing, but how do you ensure that the same exception doesn’t come up again next week?
Find a permanent solution instead of starting over every time
A systematic approach to resolving issues starts with a fixed catalog of your exceptions, with an owner, an SLA, and a resolution path for each type. This allows you to handle non-standard invoices without having to search for the exception all over again.
Cataloging
Use the types listed at the beginning of this page as a starting point, and assign each type an owner, an SLA, and a resolution path. In the Belgian SMEs we work with, approval thresholds and separation of duties often rest with a small number of people. In such cases, a five-role model is too cumbersome, and a single person may hold multiple roles.
Measurement
Keep track of the number and turnaround time for each type so that the type is included in your report.
Remove
Correct a master data error—such as a missing conversion factor—once at the source instead of fixing it again on each invoice. Two identical corrections for the same supplier are a sign that you should make this a standard procedure. Halving the number of exceptions also shortens processing time and reduces the risk of errors. Read more about automating processes with RPA. If you want to let some of those solutions be decided without human intervention, what limits need to be established?
The assurances you need before making a decision
Before you allow an exception to be resolved autonomously, you must ensure four things: every action is reversible and logged, there is a monetary limit per type, a random sample verifies accuracy, and there is a single emergency brake. Be aware that the responsibility for an automatic solution remains with you. We, for our part, set one limit. For us, this is a design choice: whatever we allow to be resolved autonomously does not post entries, make payments, approve transactions, or access supplier data.
Reversible and logged
Require that every action be reversible and logged: if something goes wrong, you can undo the action and see what happened.
A limit per type
Require a monetary limit for each type: above that limit, a person makes the decision, so that you cap the potential damage for each type in advance.
A random sample that measures accuracy
Require a spot check to verify accuracy: have a person review a portion of the automated solutions so you know how good they are.
One emergency brake
Call for a single emergency brake: a single action that stops all automated solutions. With these four safeguards, you’ll know how to get started, but when is it better not to start at all?
When You Shouldn’t Get Involved in This
If you don’t have a catalog of your exceptions, you’re automating something you don’t understand. If your exceptions stem from your master data, then it’s a data cleanup—not an automation project. Is your volume small? In the projects we see, when the volume is small, a small team with a clear plan is faster than an implementation. In all those cases, we don’t make any money off it, and we’re still saying that. So what can you do as early as tomorrow, without software and without us?
First Steps Without Us
Keep track of the exceptions you encounter over the course of two weeks and note which category they fall into. If you’d also like to know how “touchless” your process already is, take the ten-question self-assessment.
– Set up a write-off rule: see how many of your exceptions are minor discrepancies—for example, under ten euros—and set up a write-off rule for that group.
– Assign an owner to each category: designate an owner for each category.
That’s just some configuration work in your existing system—not a project. After two weeks of data entry, you’ll have an initial catalog, which gives you a starting point based on your own invoices, not those from a demo.
Frequently Asked Questions
Three questions remain, even if you’re familiar with the safeguards and the first steps.
Will exceptions ever disappear completely?
No. Exceptions don’t disappear completely, but you can reduce their number and resolve the rest more quickly.
Who is responsible if an automated solution is faulty?
You. Count on the fact that the responsibility will remain with you, so insist that every action be reversible and logged, so that you can verify what happened and undo it.
Do you need to switch ERP systems for this?
No. In the projects we’ve seen, you don’t need to switch ERP systems to systematically resolve exceptions. To learn how this works in practice, read about how we automate accounts payable.
Do you know how many invoices ended up with a person last month, and why?
We look at your exceptions with you and tell you honestly whether automation pays off or configuration is enough.