Dunning is the structured sequence of reminders a business sends to collect an overdue invoice, escalating in tone and channel as the debt ages.
Why it matters in B2B collections
Dunning is the operational core of collections. Done well it is a schedule: a predictable ladder of contact that starts before the due date and escalates on a defined cadence, so nothing is forgotten and no customer is surprised. Done badly it is a person remembering to send emails, which fails silently at exactly the moment volume grows.
The ladder starts before the due date
The most effective dunning step is the one sent while the invoice is still current. A short pre-due reminder confirms the invoice was received, arrived at the right contact, matches a purchase order, and is scheduled for payment. Most late payments in B2B are not refusals, they are administrative: the invoice went to the wrong inbox, or it is stuck awaiting an approval nobody chased. A pre-due touch surfaces all of that while it is still cheap to fix.
B2B dunning is not consumer dunning
Consumer dunning addresses one person who owes money and can choose to pay. B2B dunning addresses an organisation, where the person reading the reminder is usually not the person who decides, and often is not the person who can release payment either. That makes the useful escalation lateral as much as vertical: moving from accounts payable to the buyer who authorised the order, or to a finance director, is frequently more effective than sending a sterner note to the same inbox.
Escalation should change the channel, not just the wording
A sequence of five emails that grow progressively firmer is a weak ladder, because they all land in the same place and can all be ignored the same way. Changing channel is what creates genuine escalation: email, then a phone call, then a formal notice, then a final demand before external recovery. Each step should also be recorded, because at the point a debt goes to recovery or litigation, a documented contact history is the evidence that reasonable steps were taken.
Stop the ladder when the invoice is disputed
A disputed invoice must exit the dunning sequence immediately. Continuing to send reminders on a balance the customer has formally queried achieves nothing, since it will not be paid until the dispute is resolved, and it actively damages a relationship by signalling that the query was not heard. Routing disputes out of dunning and into a resolution workflow is one of the highest-value rules a collections process can have.
Dunning: common questions
What is a dunning letter?
How often should you send dunning reminders?
What is the difference between dunning and debt collection?
Go deeper: How Finero runs autonomous dunning.
How this connects to other terms
- Promise to pay (PTP)
A promise to pay is the outcome a dunning sequence is trying to produce.
- DSO (days sales outstanding)
Consistent dunning is the most direct lever on DSO.
- Accounts receivable (AR)
Dunning is the operational process applied to the AR ledger.