A past due notice is the formal step after friendly reminders: it states the invoice facts, sets a deadline, and creates a written record you can rely on if the account escalates. Below are a short past-due email, a formal letter, and a compact invoice summary you can drop into either - followed by ten variants covering friendly through 90-day notices.
Start here: short email, formal letter, invoice summary
Short past-due email
Subject: Past due notice: invoice [Invoice number] ([X] days)
Hi [Client name], This is a past due notice for invoice [Invoice number] for [Outstanding amount], which was due on [Original due date] and is now [X] days past due. Please arrange payment at your earliest convenience: [Payment link] If payment has already been sent or the invoice is disputed, reply to this email and we will update our records. Regards, [Your name] [Your company name]
Formal past-due letter
Use this layout when you need a document rather than an email - to print, attach as a PDF, or send by post. It doubles as your written record if the account is later escalated.
[Your company name] [Your address] [Date] [Client name] [Client company name] [Client address] RE: PAST DUE NOTICE - INVOICE [Invoice number] Dear [Client name], Our records show that invoice [Invoice number], issued on [Invoice date] in the amount of [Outstanding amount], remains unpaid. The invoice was due on [Original due date] and is now [X] days past due. Please remit payment in full by [payment deadline]. Payment can be made via [Payment link / payment details]. If payment has already been made, please disregard this notice and send remittance details so we can reconcile our records. If you believe this invoice is in error or wish to discuss payment arrangements, contact us at [phone / email] before the deadline above. Sincerely, [Your name] [Title] [Your company name]
Compact invoice-summary block
Paste this at the top of any notice so the recipient can verify the debt at a glance.
PAST DUE NOTICE Invoice number: [Invoice number] Invoice date: [Invoice date] Original due date: [Original due date] Days past due: [X] Amount outstanding: [Outstanding amount] Payment link / details: [Payment link]
Past due notice templates by situation
1. Friendly past-due notice
For the first past-due contact with a client who usually pays. A notice in name, a nudge in tone.
Subject: Past due notice: invoice [Invoice number]
Hi [Client name], A quick heads-up that invoice [Invoice number] for [Outstanding amount] went past due on [Original due date]. I'm sure it's just slipped through - here's the payment link to settle it: [Payment link] If anything about the invoice needs clarifying, just reply and I'll sort it out. Thanks, [Your name]
2. Formal past-due notice
For repeat late-payers or larger balances. Formal register, factual tone, and a stated deadline.
Subject: Formal past due notice - invoice [Invoice number]
Dear [Client name], This is a formal notice that invoice [Invoice number] for [Outstanding amount], due on [Original due date], remains unpaid and is now [X] days past due. Please remit payment by [payment deadline] using the following link: [Payment link] If the invoice is disputed or payment has already been sent, contact us immediately at [phone / email] so we can resolve the matter. Sincerely, [Your name] [Your company name]
3. Second past-due notice
The first notice went unanswered. Reference it, restate the facts and tighten the deadline.
Subject: Second notice: invoice [Invoice number] remains past due
Dear [Client name], This is our second notice regarding invoice [Invoice number] for [Outstanding amount], due [Original due date]. Our first notice was sent on [date of first notice] and we have not received payment or a response. Please arrange payment by [payment deadline]: [Payment link] If there is a reason payment has not been made - a dispute, missing paperwork or cash-flow timing - contact us at [phone / email] so we can agree a way forward. Sincerely, [Your name] [Your company name]
4. Past-due notice before escalation
The last notice before you move to a final demand. Name the next step plainly, without threats you cannot support.
Subject: Past due notice: invoice [Invoice number] - action required by [payment deadline]
Dear [Client name], Despite previous notices, invoice [Invoice number] for [Outstanding amount] (due [Original due date], now [X] days past due) remains unpaid. Please make payment by [payment deadline]: [Payment link] If the balance is not settled or a payment arrangement agreed by that date, we may need to escalate this matter, subject to our agreement and applicable law. Please contact us immediately at [phone / email] if the invoice is disputed. Sincerely, [Your name] [Your company name]
5. Past-due notice with a payment plan option
When the client has acknowledged a cash-flow problem. Offering an installment path often recovers more than pressing for full payment.
Subject: Invoice [Invoice number]: payment options
Hi [Client name], Invoice [Invoice number] for [Outstanding amount] is now [X] days past due. I understand cash flow can get tight, so I'd rather agree a plan than keep sending notices. Two options: 1. Full payment by [payment deadline]: [Payment link] 2. A payment plan - for example, [number] installments of [installment amount], starting [start date]. Reply by [reply-by date] with the option that works, and I'll send confirmation. If neither fits, call me at [phone] and we'll find something that does. Regards, [Your name]
30-, 60- and 90-day past due notices
Escalate the register as the account ages. Each notice below can be sent as an email or dropped into the formal letter layout above.
30-day notice
One month past due. Still professional and cooperative, but with a firm deadline and a named next step.
Subject: Invoice [Invoice number]: 30 days past due
Dear [Client name], Invoice [Invoice number] for [Outstanding amount] is now 30 days past its due date of [Original due date]. Please arrange payment within the next 7 days: [Payment link] If you are unable to pay in full at this time, contact us at [phone / email] to discuss a payment arrangement. If payment has been sent, please share remittance details so we can update our records. Sincerely, [Your name] [Your company name]
60-day notice
Two months past due. Reference the prior notices, state the account status, and make the consequence of continued non-payment clear but factual.
Subject: Invoice [Invoice number]: 60 days past due - response required
Dear [Client name], Invoice [Invoice number] for [Outstanding amount] is now 60 days past due. We have sent previous notices on [dates] without receiving payment or a response. Your account is now on hold pending resolution. To restore normal terms, please pay the outstanding balance by [payment deadline]: [Payment link] If the invoice is disputed, contact us immediately at [phone / email]. Otherwise, we may need to escalate this matter, subject to our agreement and applicable law. Sincerely, [Your name] [Your company name]
90-day notice
Three months past due - typically the last notice before collections or formal action. Keep it factual; do not threaten steps you will not take.
Subject: Final past due notice: invoice [Invoice number] - 90 days
Dear [Client name], Invoice [Invoice number] for [Outstanding amount], due [Original due date], is now 90 days past due despite repeated notices. This is our final past due notice. Please pay the full balance by [payment deadline]: [Payment link] If we do not receive payment or hear from you by that date, we intend to pursue the remedies available to us under our agreement and applicable law, which may include referring the account to a collections process. Please contact us immediately at [phone / email] if the invoice is disputed or if you wish to agree a payment plan. Sincerely, [Your name] [Title] [Your company name]
A note on consequences: only reference escalation steps, late fees or interest that your agreement and local law actually permit. When in doubt, use neutral wording like "we may need to escalate this matter, subject to our agreement and applicable law."
Where notices fit in the escalation path
Timeline: reminders to formal notices to escalation
- Day 1-13 Friendly and second reminders
- Day 14-29 Firm reminder
- Day 30-44 Formal past due notice (30-day)
- Day 45-89 Second notice, then 60-day notice
- Day 90+ 90-day final notice, then escalation
Before the notice stage, try a second payment reminder or a firm reminder - they resolve most late invoices without formal language. After the 90-day notice, the next message is a final notice.
Related templates
- Invoice reminder email templates - the full sequence from first nudge to final demand.
- Invoice late fee wording - if your terms allow fees on past-due balances.
- Final notice for an unpaid invoice - the step after your last past-due notice.
- Accounts payable follow-up email - when the notice goes to an AP department.
- Unpaid invoice follow-up schedule - day-by-day timing for the whole process.
Send every notice on time, automatically
ChaseAI escalates from friendly reminder to formal notice on schedule, so no invoice slips through.
