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What Is Invoice Dunning? Definition + Simple Explanation

Demystified. Invoice dunning is the process of collecting overdue payments through reminders and escalation. Learn how it works and why Nudgexa makes it simple.

BMBrycen Medart

Mar 24, 2026 Growth Tips6 min read

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What Is Invoice Dunning?

Dunning = The process of collecting an overdue payment through reminders, follow-ups, and escalation until the debt is paid or formally written off.

The word comes from old English ("dun" = to make persistent demands for payment), and it's still used in finance/accounting today.

Simple version: Dunning is how you get paid when someone doesn't pay on time.

Invoice dunning works best when each payment reminder matches the stage of the overdue invoice.

Good invoice dunning keeps the process professional even when the invoice is getting older.


The Dunning Process (Step-by-Step)

Step 1: Invoice Sent

You send invoice to customer for $5,000, due by April 15.

Step 2: Payment Deadline Passes

April 15 comes and goes. No payment received.

Step 3: Dunning Begins

You send reminders/follow-ups asking for payment.

StageDays OverdueActionTone
Reminder 11-3 daysFirst gentle email/messageFriendly ("did this slip through?")
Reminder 25-7 daysSecond more pointed reminderProfessional ("we need payment by X")
Reminder 310-14 daysThird urgent follow-upDirect ("this is now a serious issue")
Escalation15-30 daysPhone call or formal noticeFormal ("payment required or account suspended")
Collections30+ daysSend to collections agency or escalateLegal/Formal

Step 4: Payment or Write-Off

Either payment comes in, or you formally write off the debt as uncollectable.


Why Dunning Exists

The reality: Not everyone pays on time.

  • Some customers are disorganized (forgot about the invoice)
  • Some are cash-strapped (don't have money to pay)
  • Some are slow-paying companies (policy is payment on day 40+)
  • Some are dodging you (never planning to pay)

Dunning handles all these cases with a process:

  1. Help honest customers pay (reminders catch mistakes)
  2. Pressure slow payers (escalation signals urgency)
  3. Identify non-payers (after X reminders, you stop trying)

Good Dunning vs. Bad Dunning

❌ BAD Dunning:

  • Aggressive immediate follow-up (day 1 after due): Customer feels bullied
  • Same tone every time: Confuses customer about urgency
  • No options offered: "Pay NOW" with no flexibility
  • Personal insults or threats: Damages relationship beyond repair
  • Too many reminders: Spammy, counterproductive

Result: Customer pays late if at all, and never works with you again.


✅ GOOD Dunning:

  • Graduated escalation (friendly → direct → formal)
  • Specific timeline ("due by April 15")
  • Multiple contact attempts (email, maybe phone for big amounts)
  • Assumes good faith first (they probably forgot)
  • Clear consequence ("payment by Friday or we pause project")

Result: Customer pays on time, relationship intact, repeat business.


Real-World Dunning Example

Scenario: You invoiced a client for $10,000 on April 1. Due April 15.

Day 15 (Due Date - No Payment)

Dunning starts.

Email 1 (Friendly):

Subject: Invoice #5234 - $10K Due Today

Hi [Client],

Just wanted to make sure you received invoice #5234 for $10,000.
It's due today, but no pressure if you're already processing it.

If you have any questions about the invoice or need me to send
it somewhere else, just let me know.

Thanks!

Tone: Assumes it's an honest mistake. Purpose: Catch people who simply forgot.


Day 20 (5 Days Late)

Email 2 (Professional):

Subject: Following Up - Invoice #5234 Now 5 Days Overdue

Hi [Client],

Invoice #5234 ($10,000) is now 5 days overdue as of today.

This sometimes happens — just checking in to see if there's
anything blocking the payment on your end. Anything I can clarify
on the invoice?

Looking forward to resolving this.

Tone: Concerned but still helpful. Purpose: Give them a gentle push + offer to help solve problems.


Day 25 (10 Days Late)

Email 3 (Direct):

Subject: Invoice #5234 is 10 Days Overdue - Payment Required

Hi [Client],

Invoice #5234 ($10,000) is now 10 days overdue. I need payment
by end of business April 28 to avoid late fees and project delays.

If there's an issue with the invoice or payment terms, let's discuss
it now so we can resolve this.

Please confirm receipt and let me know when payment will arrive.

Tone: Formal, time-bound, consequence-focused. Purpose: Signal this is serious and offer last chance to work it out.


Day 30 (15 Days Late)

Phone call or formal notice:

[Name],

Invoice #5234 is now 15 days overdue. Despite multiple attempts
to collect, we still don't have payment.

We need payment by [date] or I'll need to:
1. Suspend work on [project]
2. Escalate to collections
3. Report to credit agencies

Let's talk about this today. This needs to be resolved by COB April 30.

Tone: Serious, legal-like, consequences real. Purpose: Make clear this is no longer optional.


Dunning in SaaS (Subscription World)

In subscription businesses, dunning works differently because payments are recurring.

Scenario: Your subscription payment fails

  • Day 0: Payment attempt fails (card declined, etc.)
  • Day 1: Dunning reminder #1 ("Your payment failed, here's how to fix it")
  • Day 3: Dunning reminder #2 ("Update your card to keep service running")
  • Day 5: Service suspended, email #3 ("Reactivate your account")
  • Day 7-14: Account deleted or handed to collections

Goal: Get them to update their payment method before service suspension.

SaaS dunning is CRITICAL because:

  • Recurring charges mean more failed payments
  • Customers want service to keep working (so they're motivated to fix it)
  • Early dunning recovers 60-80% of failed subscriptions

Is There a Difference Between Dunning and Collections?

Technically, yes:

  • Dunning = Your internal process (you do the reminding)
  • Collections = Formal debt collection (often handed to a collections agency)

Timeline:

  • Days 1-30: Dunning (you handle it)
  • Days 30-60: Dunning escalation (you + maybe lawyer letter)
  • Day 60+: Collections (sent to 3rd party agency)

When you send to collections:

  • You pay the agency 20-30% of what they collect
  • They become legally responsible for collection
  • You lose direct relationship control
  • But legally, you're protected (they follow collection laws)

How to Avoid Too Much Dunning

Prevention > Collection

The best dunning process is one you never need to use, because customers pay on time.

How to prevent late payments:

  1. Clear invoice terms ("Due April 15, not Net 30")
  2. Specific due date (not vague language)
  3. Easy payment methods (multiple options)
  4. Preemptive reminder (3 days before due, not after)
  5. Consequence messaging ("Payment by Friday so we can start phase 2")

Dunning in Different Industries

Freelancers/Agencies

  • Dunning: Email reminders, maybe a phone call
  • Timeline: Escalate quickly (they need the money)
  • Example: Invoice $5K on Monday, 5 reminders by Friday if not paid

SaaS/Subscriptions

  • Dunning: Automated reminders (hundreds at a time)
  • Timeline: 5-10 attempts over 2 weeks before suspension
  • Example: Failed payment triggers 3 automated reminders before service cuts off

B2B/Enterprise

  • Dunning: Formal process, often approved by finance
  • Timeline: 30-60 days standard terms (Net 30, Net 60)
  • Example: Invoice sent, 30-day wait, then formal letter if not paid

Technology for Dunning

Manual (Email + Spreadsheet)

  • You send emails yourself
  • Track in a spreadsheet
  • Cost: Your time (~2-3 hours/month if 10+ overdue invoices)
  • Best for: <5 invoices/month

Automated Dunning (Nudgexa, Wave, Stripe)

  • Tool sends reminders automatically
  • Tracks status automatically
  • Cost: $15-50/month
  • Best for: 10+ invoices/month

Formal Collections Dunning

  • Dunning process in QuickBooks, NetSuite, or Billtrust
  • Integrates with accounting system
  • Cost: $50-200/month
  • Best for: $1M+ businesses with formal dunning requirements

Key Takeaways

  1. Dunning is normal — Most businesses have to follow up on overdue payments
  2. Good dunning is graduated — Start friendly, escalate gradually
  3. Prevention beats collection — Clear invoices + preemptive reminders avoid dunning
  4. Automate if scaled — Manual dunning doesn't work at 20+ invoices/month
  5. Tone matters — Aggressive dunning damages relationships; professional dunning gets paid

Common Dunning Questions

Q: Is dunning legal? A: Yes, as long as you don't threaten or harass. Reminders are perfectly legal.

Q: How long should I dunning before giving up? A: 30-60 days is typical. After that, escalate to collections or write it off.

Q: Should I charge late fees? A: Yes (if legal in your area). Late fees work as dunning (customer wants to avoid them).

Q: Can I dunning too hard? A: Yes. Aggressive dunning can backfire (client pays hostile or doesn't pay at all).

Q: What if they just won't pay? A: After 60 days with no response, you have options: Collections agency, sue, or write off as bad debt.


Next Steps

If you're sending 5+ invoices/month and dealing with late payments:

  1. Document your dunning process (what reminders to send, when, what tone?)
  2. Automate if possible (Nudgexa or similar, $19/month)
  3. Track DSO (measure how many days to average payment)
  4. Iterate (adjust reminders based on what works)

Effective dunning is an investment. For every dollar you recover in faster payments, you gain cash flow + peace of mind.

Start automating your dunning process today with a 7-day free trial. Credit card required.

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Written by Brycen Medart on 3/24/2026