Past due invoice email templates for every stage of overdue

Past due invoice emails work best when the tone tracks the age of the balance. A note at one day past due should assume the customer forgot. A note at ninety days should state what happens next if they do not pay. Sending the same message at every stage is why so many overdue emails get ignored.

The templates below are mapped to five milestones: 1, 15, 30, 60, and 90+ days past due. Each one names the invoice and amount, gives a payment link, and shifts tone as the balance ages. Fill in the [Placeholders] and send the one that matches where the invoice sits today.

How to escalate tone as invoices age

Tone is the lever that decides whether a past due email gets paid or ignored. Get it wrong in either direction and you lose. Threaten on day one and you burn a good customer's goodwill over an oversight. Stay breezy at ninety days and you signal that the debt is not serious, so it keeps sliding.

The progression is simple. Early emails assume good faith: the customer is busy and the invoice slipped. Middle emails get specific and ask for a commitment, a date or a payment. Late emails state consequences plainly and put a deadline on them. Across all of them, the facts stay the same, the invoice number, the amount, the days past due, and a way to pay in one click. Only the framing hardens.

There is a second reason to escalate by milestone rather than by gut feel. An invoice that is 5 days late and one that is 75 days late carry very different risk, and they deserve different effort. Treating them the same wastes attention on the easy ones and lets the dangerous ones slide. The milestones below give you a default for each band, so a busy week never means a 90-day balance gets the same soft nudge as a 1-day one.

Below, each milestone gets its own template. The day counts assume net-30 terms. Tighten the spacing for shorter terms and loosen it for longer ones.

Template: 1 day past due

At one day late, assume the customer forgot. Keep it warm and short.

Subject: Invoice [Invoice number] is now past due

Hi [Customer name],

Invoice [Invoice number] for [Amount] was due yesterday, [Due date], and is showing as unpaid. It probably just slipped through.

You can clear it in one click here: [Payment link]

If you have already paid, thank you, please ignore this. If anything looks off, reply and we will sort it.

Thanks,
[Your name]
[Company name]

When to send this: 1 day past the due date, as a friendly first nudge.

Template: 15 and 30 days past due

By two weeks, a reminder is no longer a courtesy. Get more specific and ask for a date. At 30 days, reference the prior touches and the day count.

15 days past due

Subject: Following up: invoice [Invoice number], [Amount] outstanding

Hi [Customer name],

Invoice [Invoice number] for [Amount] was due on [Due date] and is now 15 days past due.

Please settle it here: [Payment link]

If you cannot pay in full right now, reply and let me know a date you expect to pay. I would rather agree something than let this keep aging.

Regards,
[Your name]
[Company name]

When to send this: at 15 days past due, when the first nudge got no response.

30 days past due

Subject: Action needed: invoice [Invoice number] is 30 days overdue

Hi [Customer name],

Despite a couple of reminders, invoice [Invoice number] for [Amount] is now 30 days past due. It was due on [Due date].

Please pay the balance here: [Payment link]

If there is a dispute or a hold on your side, I need to hear it this week so we can resolve it before it ages further.

Regards,
[Your name]
[Company name]

When to send this: at 30 days past due, as a firm escalation that references earlier touches.

Template: 60 and 90+ days past due

Past 60 days, name the consequences. Past 90, send a final demand with a deadline before the account moves to collections.

60 days past due

Subject: Invoice [Invoice number]: action required to avoid a hold

Hi [Customer name],

Invoice [Invoice number] for [Amount] is now 60 days past due, originally due [Due date].

To keep your account in good standing and avoid a hold on new orders, please pay in full by [Final due date]: [Payment link]

If something is blocking payment, reply today and we will work out a path together.

Regards,
[Your name]
[Company name]

When to send this: at 60 days past due, when continued service or new orders are at stake.

90+ days past due (final notice)

Subject: Final notice: invoice [Invoice number], [Amount] outstanding

Hi [Customer name],

This is a final notice on invoice [Invoice number] for [Amount], originally due [Due date] and now [Days overdue] days past due.

Unless payment in full reaches us by [Final due date], or you contact us to arrange terms, this balance will be referred to [Collections agency or legal step] on [Escalation date].

Pay now to stop this: [Payment link]

We would much rather resolve this directly, so please reply today.

Regards,
[Your name]
[Company name]

When to send this: at 90+ days past due, as the documented final demand before handing the account to a third party.

Personalization tokens that lift reply rates

A past due email that names specifics gets answered more often than a generic chase. Pull these tokens straight from your AR ledger:

• [Invoice number] and [Amount]. Non-negotiable. The customer should never have to go looking.
• [Days overdue]. A concrete number ("47 days past due") lands harder than "overdue."
• [PO number]. For customers whose AP team matches against a purchase order, including it removes a reason to stall.
• [Customer name] and a real sender. A named person, not "Accounts," signals someone is actually watching this.
• [Final due date] and [Escalation date]. Specific deadlines create urgency that "as soon as possible" never will.

Pull these from the ledger automatically wherever you can. Tokens you have to fill in by hand get skipped under pressure, and a half-personalized email ("Hi , invoice is overdue") does more harm than a plain one. The goal is an email that reads as if a person looked at this exact account, because the ones that feel automated get treated as automated. For a wider library of stage-by-stage messages, see the collection email templates, and to run these milestones as a scheduled cadence, build a payment reminder email sequence.

Automating stage-based escalation with Rex

The hard part of past due email is not writing the templates. It is knowing, across hundreds of open invoices, which one is at 1 day, which is at 47, and which crossed 90 overnight, then sending the right message for each, every day, without missing one. Done by hand, the calendar always wins. Invoices age past the milestone before anyone notices.

Rex does this work continuously. It tracks every invoice's exact age, sends the milestone-appropriate message on its own, and hardens the tone as a balance moves from 1 to 15 to 30 to 60 to 90+ days, with no human chasing the calendar. It personalizes each message from the live ledger, reads replies, and pauses the instant a customer disputes a charge or commits to a date, routing those to a person with full context. When payment lands, Rex stops. Your team only sees the accounts that need a real decision.

See how Rex escalates overdue invoices across your whole ledger without anyone watching the calendar.