Dunning is the structured process of contacting customers to remind them about overdue invoices and request payment. It is the core operational discipline of B2B collections and the most-used touchpoint between AR teams and customers.
Dunning is the operational workhorse of B2B collections. Every overdue invoice triggers a dunning sequence designed to remind, escalate, and ultimately resolve the payment. Done well, dunning compresses DSO, lifts CEI, and preserves customer relationships. Done poorly, it produces ignored emails, frustrated customers, and aged receivables that eventually become bad debt. For most enterprise AR teams, the quality of the dunning process is the largest controllable lever on collections performance.
While each company tailors its dunning strategy to its customer base, most B2B sequences follow a five-stage escalation pattern.
The cadence varies by industry: SaaS uses tighter sequences (every 7 days from day 1), construction extends timing to match longer payment norms, and CPG balances dunning intensity against retailer relationship value.
The most effective AR teams start dunning before invoices go overdue. Proactive payment reminders sent 3 to 5 days before the due date can lift on-time payment rates by 15 to 25 percent. They surface invoice receipt problems early (customer never received it, or the wrong PO number), correct dispute issues before they age, and reduce the volume of overdue dunning the team has to do.
Proactive reminders work best when customised: a customer with a strong payment history gets a brief courtesy note; a customer with a history of late payment gets a more pointed reminder with the invoice attached and the consequence of late payment summarised.
Mistake 1: Treating all customers the same. A blanket dunning sequence applied to every customer ignores the difference between a Fortune 500 strategic account (which needs careful handling) and a small commodity customer (where the sequence can be more direct). Modern AR teams segment dunning by customer value, payment history, and account size.
Mistake 2: Email-only dunning. Email is the default channel but its response rate drops below 30 percent after the first two messages. Best practice combines email with phone calls, customer portals, and where appropriate AI voice calls for the later stages of the sequence.
Mistake 3: Manual dunning capacity limits. Even well-staffed AR teams work only 30 to 40 percent of overdue invoices, focused on the largest balances. The long tail of smaller overdue invoices receives no outreach and ages into bad debt by default.
Mistake 4: Inconsistent execution. A dunning sequence works only if every customer with an overdue invoice receives the correct message at the correct time. Manual teams routinely skip steps, delay outreach during busy periods, or send the wrong template, undermining the sequence's effectiveness.
Agentic collections platforms change dunning from a capacity-constrained manual workflow to a continuously running automated process. Four capabilities drive the shift:
Mid-market collections teams typically see a 15 to 25 percent lift in dunning response rates and an 8 to 15 day DSO reduction within 90 days of agentic deployment, with the gains coming primarily from coverage expansion and personalisation.
Dunning is the systematic process of contacting customers to remind them about overdue invoices and request payment. It is the core operational activity of B2B collections, typically involving a structured sequence of emails, phone calls, statements, and in later stages, escalation to formal demands or third-party collections.
Dunning is the customer-facing outreach portion of collections: sending reminders, calls, and formal notices. Collections is the broader function that includes dunning plus credit risk assessment, dispute resolution, cash application coordination, and write-off decisions. Dunning is the most visible operational layer of collections.
Standard B2B sequences include 4 to 6 touchpoints before formal escalation, typically spanning 30 to 60 days. The first messages are courteous reminders, escalating to formal demands. After day 90, accounts are typically referred to third-party collections or written off. The right cadence depends on industry norms and customer payment behaviour.
Yes, when applied uniformly without segmentation. A Fortune 500 strategic account treated with the same dunning sequence as a small late payer can feel disrespected. Best-practice dunning segments customers by payment history, relationship value, and dispute frequency, adapting tone and channel to preserve the relationship while still resolving the overdue invoice.
Automated dunning uses software to send dunning messages without manual intervention based on rules and customer attributes. Modern AI-native platforms go further: they personalise message content, channel, and timing dynamically to each customer's payment behaviour, achieving response rates 15 to 25 percent higher than rule-based automation.
Track response rate (percentage of dunning messages that produce a customer reply or payment), payment rate (percentage that convert to cash), and stage escalation rate (percentage that reach final demand). Pair these with DSO and CEI trends to see whether dunning improvements translate to overall AR performance gains.
