How to build a dunning email sequence that reduces late payments

A dunning email sequence is a scheduled set of reminders that follows an invoice from before its due date through a series of escalating overdue notices. Each message gets firmer than the last. The goal is not to send more email. It is to collect most invoices with an early, polite nudge and reserve the stern notices for the few that genuinely stall.

In B2B, late payment is usually a process problem, not a refusal. An invoice lands in a shared inbox, waits on a PO match, or sits behind an approval. A steady sequence keeps your invoice in front of the right person at each stage without anyone on your team chasing by memory. Build it once, run it the same way every time, and the routine follow-up stops eating your week.

Dunning sequence basics for B2B

A dunning sequence has three jobs. It reminds the customer the invoice exists. It escalates pressure in proportion to how overdue the balance is. And it tells you when an account needs a human instead of another email.

Tone has to track the age of the invoice. The first touch assumes the customer simply has not gotten to it. The middle touches get specific about the amount, the days overdue, and what happens next. The final touch states the consequence (a hold on new orders, escalation to collections) and gives a hard date. Every email names the exact invoice and amount and puts a payment link in front of the customer. Keep each one short enough to read on a phone.

B2B differs from consumer dunning in two ways. Invoices are larger, so a single stuck account matters more. And the buyer is rarely the payer, so your sequence often has to reach an AP team, a manager, and a procurement contact at different stages. Build CC escalation into the cadence, not just tone escalation.

Designing your touch cadence

Anchor the cadence to your payment terms. The example below assumes net 30. Shift the days to fit net 15, net 45, or net 60.

• 3 days before due: a friendly pre-due reminder.
• Due date: a short prompt on the day.
• 3 to 5 days past due: first overdue notice, still assuming an oversight.
• 15 days past due: escalation notice, firmer, offers a payment plan.
• 30 days past due: second escalation, loops in a manager or AP lead.
• 45 to 60 days past due: final notice with a hard date and stated consequence.

Six touches is a reasonable ceiling for most ledgers. More than that and the reminders lose force. Space them so each message has time to land and be acted on before the next one fires. And remember the cadence is a default, not a rule: a customer who always pays on day 35 does not need the same pressure as one who has gone silent at day 20.

Email templates for each dunning step

Fill the bracketed placeholders before sending. Each template is followed by a note on when to use it.

Pre-due reminder

Subject: Invoice [Invoice number] is due [Due date]

Hi [Customer name],

A quick heads up that invoice [Invoice number] for [Amount] is due on [Due date].

You can pay it here: [Payment link]

If it is already scheduled, thank you, and ignore this note. If anything looks off, reply and we will sort it.

Thanks,
[Your name]
[Company name]

When to use: a few days before the due date, as a courtesy.

First overdue notice

Subject: Invoice [Invoice number] is now past due

Hi [Customer name],

Invoice [Invoice number] for [Amount] was due on [Due date] and is now past due. These things slip through, so no problem if it has.

You can settle it here: [Payment link]

If the payment is held up for any reason, or you need the invoice resent, just reply.

Thanks,
[Your name]
[Company name]

When to use: within the first week past due, before the balance ages further.

Escalation notice

Subject: Action needed: invoice [Invoice number] is [Days overdue] days overdue

Hi [Customer name],

We still have not received payment for invoice [Invoice number] for [Amount], due on [Due date] and now [Days overdue] days overdue.

Please pay the balance here: [Payment link]

If paying in full right now is difficult, reply and tell us. We would rather agree a date with you than let this keep aging.

Regards,
[Your name]
[Company name]

When to use: once an invoice passes the two-week mark with no response.

Final notice

Subject: Final notice: invoice [Invoice number], [Amount] outstanding

Hi [Customer name],

This is a final notice on invoice [Invoice number] for [Amount], originally due [Due date]. The balance is unpaid despite earlier reminders.

Please pay in full by [Final due date]: [Payment link]

If we do not receive payment or hear from you by then, the account will be escalated for collection and we may place a hold on new orders. We would much rather resolve this with you, so reply today if there is an issue we should know about.

Regards,
[Your name]
[Company name]

When to use: as the last automated touch before a person takes over. For a more formal version of this ladder, see our dunning letter templates, and for the gentler end of the spectrum the payment reminder email sequence.

Handling disputes and promises mid-sequence

The fastest way to wreck a sequence is to keep sending reminders after the customer has replied. Two replies should stop the automation cold.

The first is a dispute. If the customer says the amount is wrong, the goods never arrived, or a credit is missing, the invoice is not collectible until that is resolved. Pause the sequence, route the case to whoever can settle it, and resume only once the balance is confirmed. Chasing a disputed invoice tells the customer you are not listening.

The second is a promise to pay. If the customer commits to a date, suspend the reminders until that date passes. Then check whether the money landed. If it did, the invoice closes. If it did not, the sequence resumes one step firmer, because a broken promise is a stronger signal than silence. Treat the promise date as a checkpoint, not the end of the matter.

Metrics that prove the sequence works

A sequence is only as good as the numbers it moves. Watch four:

1. DSO. The headline. If your dunning is working, days sales outstanding trends toward your terms. See how to reduce DSO for the wider set of levers.
2. Paid-at-step rate. What share of invoices clear at the pre-due, first, and escalation touches. A healthy sequence collects most invoices in the first two steps.
3. Final-notice rate. How many accounts reach the last email. The lower the better. A rising number means the early touches are not landing.
4. Dispute and reply rate. How often customers push back. A spike here often points to a billing accuracy problem upstream, not a collections one.

Read these together. If the paid-at-step rate is high but DSO is still climbing, the problem is invoice timing, not the sequence. If disputes are high, fix the invoice before you fix the email.

Running adaptive dunning with Rex

A written sequence assumes every account is the same. They are not. Rex runs the sequence per invoice, across the whole ledger at once, and adapts each touch to the customer in front of it. It personalizes the message with the real invoice, amount, and history, picks the tone the account's payment behavior warrants, and sends at the right age without anyone watching the calendar.

The part teams find hardest to do by hand, Rex does by default. It reads each reply, and the moment a customer raises a dispute or promises a date, it pauses that invoice's sequence and routes the case, then picks the cadence back up if the promise lapses. Your team stops sending reminders and stops policing pauses. It sees only the accounts that need a decision.

See how Rex runs dunning end to end across every open invoice.