Guide · 6 minute read

Overdue invoice email: what to write, and when

An overdue invoice email names the invoice number, amount and due date in the first line, includes a link to pay, and asks one clear question: when can you expect payment? Send the first one 1 to 3 days after the due date, then at about 7, 14 and 30 days, each a little firmer, adding a deadline and then a next step.

By the Babara team · Updated

8.5 days late is how late the average US small-business invoice was paid in the June 2026 quarter, per Xero Small Business Insights. A short reminder on day one is often all it takes.

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5 overdue invoice email templates, by how late it is

Replace everything in [brackets]. Want one written for you? The free reminder email writer fills in your details and picks the tone.

1. 1–3 days overdue: the friendly nudge

Subject: Quick reminder: invoice #[number] was due [due date]

Hi [Name],

Just a quick note that invoice #[number] for [amount] was due on [due date]. It may simply have slipped through, so here’s the link to pay: [link].

If it’s already on its way, thank you, and please ignore this.

Best,
[You]
2. 7 days overdue: the clear ask

Subject: Invoice #[number] is now 7 days overdue

Hi [Name],

I’m following up on invoice #[number] for [amount], which was due on [due date] and is now a week overdue.

Could you let me know when I can expect payment? You can pay here: [link].

If something is holding it up, a PO number, an approval or a question about the work, just reply and I’ll sort it out.

Thanks,
[You]
3. 14 days overdue: a date, please

Subject: Second reminder: invoice #[number], payment by [date]?

Hi [Name],

Invoice #[number] for [amount] is now two weeks overdue. I wrote about it on [date].

Please pay it by [date, about 5 working days away]: [link]. If that date doesn’t work, reply with one that does and I’ll note it.

Thanks,
[You]
4. 30 days overdue: the final reminder

Subject: Final reminder: invoice #[number] is 30 days overdue

Hi [Name],

Invoice #[number] for [amount], due on [due date], is now 30 days overdue. I reminded you on [date 1] and [date 2].

Please pay the full amount by [deadline, about 7 days away]: [link].

If I don’t receive payment or hear from you by then, I’ll pause any ongoing work and send a formal demand letter.

If paying in full is hard right now, reply and we can agree a short plan.

Thanks,
[You]
5. 45+ days overdue: before you go further

Subject: Invoice #[number]: last chance before a formal demand

Dear [Name],

Despite my reminders of [dates], invoice #[number] for [amount], due on [due date], is still unpaid, and I haven’t had a reply.

Please pay by [deadline]: [link]. After that date I will send a formal demand letter and, if needed, file a claim in small claims court for the amount and court costs.

I would much rather settle this between us. A reply with a date, or a plan, is all it takes.

Sincerely,
[You]
Step by step

How each reminder gets firmer

Same facts every time. What changes is the ask and the deadline, never the politeness.

StepToneThe askDeadline
FriendlyAssume they forgotHere’s the linkNone
ClearPolite, directWhen can I expect it?Ask for one
FirmMatter-of-factPay by a date~5 working days
FinalCalm, seriousPay or I’ll take a next step~7 days
FormalFormal letterPay or small claims10–14 days
Subject lines

8 subject lines for an overdue invoice

Specific beats clever. The invoice number makes it findable; the days late make it real.

  1. Quick reminder: invoice #[number] was due [date]
  2. Invoice #[number] for [amount]: still open
  3. Is invoice #[number] stuck somewhere?
  4. Invoice #[number] is now [X] days overdue
  5. Second reminder: invoice #[number], payment by [date]?
  6. Final reminder: invoice #[number] is [X] days overdue
  7. Action needed: invoice #[number] before [date]
  8. Invoice #[number]: last chance before a formal demand

6 rules that get overdue invoices paid

  1. Lead with the invoice

    Number, amount and due date in the subject or first line. Your client might be looking at 40 invoices.

  2. Always include the pay link

    Every extra step, finding the bank details or logging in somewhere, is a reason to do it later.

  3. Reply to your own thread

    Keep every reminder in one email thread, so the history is one scroll away for them, and for you.

  4. Ask a question

    “Is anything holding it up?” gets replies. Replies turn into dates, and dates into payments.

  5. Get firmer, not angrier

    Each step adds a date or a consequence, never more exclamation marks.

  6. Send on a weekday morning

    Early in the week and early in the day, when people work through their inbox.

Invoice overdue or past due: same thing, same fix

An invoice is overdue (or past due) from the day after its due date. If no date was agreed, UK law treats a business invoice as due 30 days after the client receives it; in the US and elsewhere, the terms on the invoice decide.

1. Past due notice, about 7 days late

Subject: Past due: invoice #[number] for [amount]

Hi [name],

This is a quick notice that invoice #[number] for [amount] was due on [due date] and is now past due. You can pay here: [payment link].

If it’s already on its way, thank you, and please ignore this. If something is holding it up, just reply and let me know.

Thanks,
[your name]
2. Overdue account reminder, several invoices

Subject: Overdue account: [number of] invoices, [total] in total

Hi [name],

A reminder that your account has [number of] overdue invoices:

#[number]: [amount], due [date]
#[number]: [amount], due [date]

Total overdue: [total]. You can pay them all here: [payment link].

Could you let me know when I can expect payment? Happy to send copies of any of them.

Thanks,
[your name]

Not sure when to send each one? See the payment reminder schedule, or follow what to do with an unpaid invoice step by step.

Charging interest? Work out the exact figure with the late payment interest calculator.

Before you start

Good questions

What does “invoice overdue” mean?
It means the due date has passed and the invoice hasn’t been paid. “Overdue” and “past due” mean the same thing. From that day you can send reminders and, between businesses in the UK, claim statutory interest and fixed compensation.
What is a past due invoice reminder?
A short email or letter telling the client that an invoice is now past its due date, with the amount, the date it was due and a way to pay. The first one should assume it was simply missed.
How do you write an email for an overdue invoice?
Put the invoice number, amount and due date in the first line, include a payment link, and ask one clear question: when can you expect payment. Keep it under 100 words and friendly at first, then add a firm date in later emails.
What do you say when an invoice is overdue?
Start with “Just a quick note that invoice #[number] for [amount] was due on [date]” and a link to pay. Assume it was missed. In later reminders, name how many days late it is and ask for a payment date.
How many days overdue before I send a reminder?
Send the first reminder 1 to 3 days after the due date, then at about 7, 14 and 30 days. Each one a little firmer. After about 30 to 45 days without a reply, move to a formal demand letter.
What is a good subject line for an overdue invoice email?
One that names the invoice and how late it is, like “Invoice #1042 is now 7 days overdue”. Specific subject lines get opened and are easy to find later.
Should I add a late fee to an overdue invoice?
Only if your contract or invoice terms said so, or your local law allows it. In the UK and EU, business clients owe statutory interest and a fixed fee; in the US each state sets its own legal rate.
What if they still don’t reply?
Try a phone call, pause any new work, then send a formal demand letter with a deadline. If that passes too, small claims court is built for amounts like most unpaid invoices.

Sources

Every link checked on . This guide is general information, not legal advice.

  1. Late payments: US small-business invoices paid 8.5 days late on average (June quarter 2026) · Xero Small Business Insights
  2. Late payment research: £11bn a year cost, 86 hours a year spent chasing · Office of the Small Business Commissioner (UK)
  3. Freelance Isn’t Free Act: payment due 30 days after the work if no date is agreed · New York State Senate
  4. Late commercial payments: charging interest and debt recovery costs · GOV.UK

Keep reading

Unpaid invoice: what to do, day 1 to day 60The steps in order, with the email, the interest and the demand letter for each.When to send a payment reminderThe 6-step schedule, as a calendar file or checklist.How to ask for payment politelyWhen to send each reminder, and word-for-word scripts.Polite ways to say “please pay”20 phrases for every stage, from heads-up to final reminder.Final payment reminderWhat it must say, 3 templates, and what to do after.Late Payment of Commercial Debts Act (UK)Interest, the £40/£70/£100 compensation and when it applies, in plain English.Demand letter for payment (US)Free generator, 3 sample letters and small claims limits.Invoice software for freelancersAn honest roundup with prices, free plans and reminders, each fact dated.Quote and invoice software without the spreadsheetSave items once, quote from them, invoice in one click.Late payment interest calculatorUK, euro area, Germany, France and Netherlands rules.

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