FREE TOOL
Dunning letter generator
A dunning letter is a written request to a customer to pay an overdue invoice, sent in stages that get firmer the longer the invoice stays unpaid. Enter your invoices and due dates, and the generator picks the right stage (first reminder, second notice, past due notice, credit hold, final demand or final notice before collections), writes the letter in a warm, plain or firm tone, and gives you a PDF, a Word file or email text. Morsa sends these for you from your own mailbox; this page is the free, do-it-yourself version.
Updated October 21, 2026
What a dunning letter must include
The invoice numbers, the customer’s PO numbers, the due dates and the open balance of each invoice, plus the total. AP departments pay by PO and invoice number; a letter without them goes to the bottom of the pile.
How late it is, in days, worked out from the due date, not the invoice date.
One clear request: pay by a date, or reply with the date you will pay.
How to pay: ACH details on the invoice, a card by phone, a check address.
Consequences, stated once and only if true: late charges your terms allow, a credit hold on new orders, referral to a collection agency.
A way to raise a dispute, because a short shipment or a wrong price is often the real reason an invoice is unpaid.
A named person to contact, with a direct email and phone number.
The dunning stages
| Stage | When | What it does | Credit hold |
|---|---|---|---|
| Courtesy reminder | 3 days before due | States the amount and due date; nothing is late yet | No |
| First reminder | 1 to 14 days late | Assumes it slipped; asks for the payment date or check number | No |
| Second notice | 15 to 29 days late | Notes there was no reply; asks for a date | No |
| Past due notice | 30 to 44 days late | Sets a pay-by date; states late charges your terms allow; warns of a hold | Warned |
| Credit hold notice | 45 to 59 days late | New orders wait until the past due balance is paid | On |
| Final demand | 60 to 89 days late | Last notice before referral; offers a call or a plan | On |
| Final notice before collections | 90+ days late | Names the referral date to an agency or attorney | Account closed to new orders |
The stages the tool writes. Day ranges are a common B2B schedule on net 30 terms; shift them if your terms are longer.
Sample dunning letters
These are the generator’s own words for an example customer with two open invoices: INV-20418 for $4,812.50 (PO 7702) and INV-20533 for $1,926.00 (PO 7731), $6,738.50 in total. Fill in the tool and every number is yours.
First reminder (1 to 14 days past due)
Subject: Invoice INV-20418 is past due: $4,812.50. Our records show invoice INV-20418 (PO 7702) for $4,812.50 is 9 days past due. It may simply have slipped through, so I wanted to check that you received it. If payment is already on its way, thank you, and please send me the payment date or check number so I can match it. If anything on it is wrong, such as a short shipment, a price or a missing credit, tell me which line and I will get it fixed right away.
Past due notice (30 to 44 days past due)
Subject: Past due notice: $6,738.50 on 2 invoices. The invoices listed below for $6,738.50 are now 38 days past due, and we have not received payment or a reply to our earlier reminders. Please pay the full balance by October 31, 2026, or reply with the date it will be paid. Under our terms, late payment charges apply: 1.5% per month on balances over 30 days. If we do not receive payment by October 31, 2026, new orders for Hollis Fabrication will be placed on credit hold until the account is current.
Credit hold notice (45 to 59 days past due)
Subject: Credit hold notice: Hollis Fabrication, $6,738.50 past due. As of today the account is on credit hold. Orders already in progress may be held, and new orders will ship once the past due balance is paid. Please pay by the date below, or call me to agree a date.
Final demand (60 to 89 days past due)
Subject: Final demand for payment: $6,738.50 past due. Despite our earlier notices, $6,738.50 remains unpaid. This is our final demand before we refer the account for collection. Please pay the full balance within 10 days. If there is a reason this has not been paid, call me before that date and we will work it out.
Final notice before collections (90 or more days past due)
Subject: Final notice before collections: Hollis Fabrication, $6,738.50. Unless the full balance is paid within 10 days, we will refer the account to a collection agency or our attorney, which may add collection costs as allowed by our terms and the law. We would much rather settle this directly. Call me before that date.
How to use the generator
Enter your company and the person signing. Both are remembered in this browser for the next letter.
Add the customer and each open invoice with its due date and open balance. The tool counts the days past due.
Leave Letter on automatic to pick the stage from the oldest invoice, or choose a stage yourself.
Set the pay-by window, any late charge your terms allow, the credit hold and a payment plan offer, and pick a tone.
Fix anything under Before you send, then download the PDF or Word file, print it, or copy it as email text.
Dunning letter or email?
Email first: it is faster, it reaches the AP inbox, and the customer can reply with a date. Use a printed letter on company letterhead for the final demand and the final notice before collections, where a signed, dated paper record helps if the account goes to an agency or to court. The generator makes both from the same details. For a ready email sequence with send dates, use the past due invoice email templates.
The modern way: let Morsa do the chasing
Most distributors and manufacturers still collect the old way: someone exports the aging on Monday, sorts it in a spreadsheet, writes a dozen emails, and calls the big ones when there is time. The ones that get chased are the ones somebody remembered.
Morsa does that job every morning. It reads the open invoices straight from your ERP, picks who to chase and at which stage, and sends each reminder from your AR person’s own mailbox, so a customer hears from Nina in accounts receivable, not from a no-reply address. When Hollis Fabrication replies that they will pay Friday, Morsa logs it as a promise to pay, sets the reminder, and asks the owner whether to release their credit hold once the money lands. Disputes (a short shipment, an old price) go to the person who can fix them, with the invoice and the PO attached. Your people approve; Morsa does the typing and the remembering.
Frequently asked questions
What is a dunning letter?
A dunning letter is a notice asking a customer to pay an invoice that is past its due date. Companies send them in stages, each one firmer, from a polite reminder to a final notice before the account goes to collections.
How many dunning letters should I send before collections?
Most B2B sellers send four to six notices over 60 to 90 days: a first reminder, a second notice, a past due notice with a pay-by date, a credit hold notice, and a final demand, then a final notice naming the referral date.
Can I charge a late fee in a dunning letter?
Only if your terms of sale or the invoice said so before the sale, and within your state’s limits. The generator mentions a late charge only when you type one, in your own words.
Do debt collection laws apply to a business customer?
The federal Fair Debt Collection Practices Act and the CFPB’s Regulation F cover consumer debts collected by debt collectors. A company collecting its own invoices from another business is generally outside them, but state laws and your contract still apply. Keep every letter factual and never threaten an action you will not take.
What is the difference between a dunning letter and a demand letter?
A dunning letter is any stage of the reminder sequence. A demand letter is the final, formal stage that states the amount, a deadline and what happens next, often sent by an attorney.
Is anything I type uploaded?
No. The letter, the PDF and the Word file are built in your browser, and your details are saved only in this browser.
Related tools
WHERE MORSA FITS
Your past-due list, chased every morning without anyone opening a spreadsheet.
Morsa reads the aging from your ERP, sends each customer the right reminder from your AR person’s own mailbox, logs every promise to pay with a reminder, and asks the owner before a credit hold is released. It works in email, Teams, WhatsApp, text or whatever your team already runs on.
