Dunning letter templates for overdue B2B invoices: 5 escalation stages that get paid

A dunning letter is a written demand for payment on an overdue invoice, and it works best as one stage in a sequence rather than a single document. Five letters across 90 days, each escalating in tone and channel, collect far more than one strongly worded email sent whenever somebody remembers. Below are the five stages, what each one has to say, and the wording that moves an invoice out of an accounts payable queue.

The templates here are written for US business to business invoices, where a company was invoiced on terms and has not paid. They are not written for consumer debt, which is governed by the FDCPA and Regulation F and needs different language and different limits.

Why a single dunning letter rarely works

An unpaid B2B invoice is almost never a refusal. It is usually an invoice sitting in a queue behind other invoices, waiting for an approval that nobody has chased. One letter, however firm, joins that queue. A sequence changes the account's status in the reader's mind each time it arrives, and that is what moves it forward.

Timing matters more than wording at the start and less at the end. Commercial collection data puts the chance of recovering a debt at roughly 50% once it is six months past due, and around 10% by the two year mark. Most of the value in a dunning sequence is captured in the first 60 days, which is why the schedule below front-loads contact.

Stage 1: the pre-due courtesy reminder, three days before the due date

This is not chasing and should not read like it. It exists to catch the large share of late payments caused by an invoice going to the wrong address, landing in a spam filter, or missing a purchase order number the customer's system requires. Sent before anything is late, it costs you nothing in goodwill.

Subject: Invoice 1043 due Friday 12 September

Hi Dana, invoice 1043 for $4,820 is due this Friday, 12 September. I wanted to check it reached the right place and that you have everything you need to process it. If you need a purchase order number added or a copy sent to a different address, just reply and I will resend today.

Keep it short and make the reply easy. The whole purpose is to surface a problem while there is still time to fix it before the due date passes.

Stage 2: the first reminder, day 3 past due

Still assume an oversight, because at three days it usually is. State the four facts in the first two lines: invoice number, amount, original due date, and what you want to happen. Do not apologize for asking.

Subject: Invoice 1043, $4,820, now 3 days past due

Hi Dana, invoice 1043 for $4,820 was due on 12 September and is showing as unpaid on our side. If it is already scheduled, could you let me know the payment date so I can note it? If it has stalled somewhere, tell me where and I will help move it. Payment link and a copy of the invoice are below.

Two things make this letter work. It asks for a specific piece of information (the payment date), which is easier to answer than a demand, and it includes the payment link so acting takes one click rather than a trip into another system.

Stage 3: the firm reminder, day 15

At two weeks the oversight assumption expires. This letter changes who it is addressed to as much as what it says: send it to your original contact and copy accounts payable, or the contact's manager if you have one. Adding a second reader is often the entire mechanism.

Subject: Overdue: invoice 1043, $4,820, 15 days past due

Hi Dana, invoice 1043 for $4,820 is now 15 days past due and I have not been able to confirm a payment date. I am copying accounts payable in case it is sitting there for approval. Our terms are net 30 and the agreement provides for a late fee of 1.5% per month on overdue balances, which would apply from 12 October if the balance is still open. Please confirm the payment date by Friday.

Only mention a late fee your contract actually authorizes. A fee that is not in the agreement is not enforceable and stating it damages your position if the invoice ends up in front of a judge. The same principle applies to interest. Our guide to late fees on invoices covers what you can charge and when.

Stage 4: the formal notice, day 30 to 45

This is the letter that reads like a document rather than a message. Send it by email and by mail on letterhead. The physical letter matters here: it reaches a different desk, it gets filed rather than deleted, and it signals that the account has changed category.

Subject: Formal notice of overdue account, invoice 1043

Dear Dana, this is a formal notice that invoice 1043, dated 13 August, in the amount of $4,820, remains unpaid 33 days after its due date of 12 September. Despite reminders on 9, 15 and 27 September, we have not received payment or a scheduled payment date. We are requesting payment in full within 10 business days, by 20 October. If the balance is not resolved by that date, we will place new orders on hold and refer the account for formal recovery. If there is a dispute regarding this invoice, please put it in writing by the same date so we can address it.

Notice what this letter does that the earlier ones do not. It recites the contact history with dates, sets a specific deadline, states a consequence, and invites a written dispute. Each of those matters later: a documented history supports a demand or a claim, and an invitation to dispute in writing closes off the argument that the customer raised concerns you ignored.

Stage 5: the final demand, day 60 to 90

The final demand is the last letter before the account leaves your hands. It should be unambiguous about what happens next and should only state steps you are genuinely prepared to take.

Subject: Final demand before referral, invoice 1043

Dear Dana, invoice 1043 in the amount of $4,820 has been outstanding since 12 September and remains unpaid following our formal notice of 7 October. This is a final demand for payment of $4,820 plus accrued late charges of $145, total $4,965, payable by 5 November. If payment is not received by that date the account will be referred for recovery without further notice, and we will seek recovery of interest and, where our agreement provides for it, legal costs.

Do not send a final demand you will not follow through on. A referral threat that never materializes teaches the customer that your sequence has no end, and it makes every future letter weaker. If you are not prepared to escalate, stop at stage 4 and price the balance as a likely write-off instead. When an invoice genuinely does become uncollectible, a sole proprietor claims it as a business bad debt on Schedule C, and if you handle your own return it is worth knowing how to get that deduction onto the filing correctly in the year it becomes worthless rather than the year it was invoiced.

What to send the letters with

Five letters per invoice is easy for one account and unmanageable for forty. The failure mode of manual dunning is not bad wording, it is inconsistency: some customers get four letters, others get none, and there is no record of who received what. That inconsistency is also what makes stage 4 weak, because the recited contact history has to be accurate.

This is the job dunning software does. It watches due dates, fires each stage on schedule, escalates the channel, stops the sequence the moment payment posts, and keeps the dated contact log that stage 4 and stage 5 depend on. Pricing across the category runs from around $49 a month for flat-fee invoice dunning to $1,169 at the top of the published range, and our debt collection software pricing breakdown prices out each model.

One thing to check before you buy: a large part of the tooling sold under the word dunning retries failed credit cards on subscriptions and cannot chase an invoice at all. If nobody at your company has a card on file, that entire class of product is the wrong fit regardless of its reviews.

When the sequence runs out

If the final demand passes without payment, three routes remain. A collection agency will typically take 10% to 50% of what it recovers, scaled by claim size, with published commercial rate cards running around 20% on a claim in the $5,000 to $49,999 band. Small claims court is cheap and fast but caps vary by state and several states bar a corporation from bringing its own small claims case without counsel. A demand letter from an attorney sits in between and often moves accounts that ignored yours.

Whichever route you choose, the dated contact history from stages 1 through 5 is the asset you carry into it. Our page on unpaid invoice collection covers how to decide between them, and best debt collection software compares the platforms that run the whole sequence for you.