What Is Dunning?
Dunning is the process of systematically communicating with customers to collect payment on overdue invoices. An effective dunning strategy uses a planned sequence of touchpoints with escalating urgency — typically across email, phone, SMS, and letters — rather than one-off chasing.
What dunning is and why it matters
The word comes from the old English verb "to dun" — to demand payment persistently — and the discipline is exactly that: persistence by design. A dunning sequence defines in advance what gets sent, when, through which channel, and in what tone: a friendly nudge before the due date, a polite reminder a few days after, firmer notices with statements attached at 30 and 60 days, and a final demand before escalation to debt recovery. The sequencing matters because most late payment isn't refusal — it's disorganization, and a well-timed reminder is often all it takes. Tone matters just as much: escalating too fast burns customer relationships, while never escalating trains customers that your invoices can wait. In subscription businesses, dunning also covers the retry-and-remind cycle for failed card payments.
A worked example
A marketing agency invoices a client $7,500 on Net 30 terms. Its dunning sequence: a courtesy note 3 days before the due date, a friendly email reminder at 5 days overdue, a second email with the statement attached at 15 days, a phone call at 30, and a final written demand at 45 warning of credit hold. In this case, the client pays after the day-15 email — the invoice had simply been sitting unapproved in their AP queue, and the attached statement pushed it through. The sequence resolved the debt at touchpoint three, with no relationship damage and no one on the agency side tracking it by hand.
How firms handle it today
Most teams do dunning manually and inconsistently — reminders go out when someone reviews the aging report and has time, tone varies by who writes the email, and sequences quietly stall when workload spikes. The result is exactly what dunning is meant to prevent: invoices aging silently.
How OCTA Flow relates to dunning
OCTA Flow automates dunning end to end — multi-channel sequences across email, WhatsApp, and AI phone calls, with tone and timing adapting to how each customer behaves — so every overdue invoice is worked on schedule and every touchpoint is logged.
Related terms
FAQ
Where does the word dunning come from?
From the archaic English verb "to dun," meaning to demand payment persistently — the modern process keeps that spirit, but on a planned schedule.
What does a typical dunning sequence look like?
A pre-due-date courtesy note, reminders at roughly 5, 15, and 30 days overdue with rising firmness, then a final demand before escalating to debt recovery.
Does dunning damage customer relationships?
Not when the sequence starts friendly and escalates gradually — most late payment is disorganization, and customers generally expect professional reminders.
See how firms automate dunning sequences → start an OCTA Flow trial.