How to follow up on an unpaid invoice (with email templates)

A calm step-by-step schedule for chasing late payments, with copy-and-paste email templates for before the due date, on the day, and when an invoice is overdue.

September 30, 2026 · 7 min read

You did the work, you sent the invoice, and the due date has come and gone. Now what? Chasing money feels awkward, especially with a client you'd like to work with again. But late payment is usually a process problem, not a relationship problem. Invoices get lost in inboxes, stuck waiting for approval, or forgotten.

A clear, polite follow-up schedule solves most of it. Here's the one we recommend, with email templates you can copy.

Before you chase: check your invoice

Before sending a reminder, make sure the problem isn't on your side:

  • Did the invoice go to the right person? Ask your contact who handles payments.
  • Are your bank details correct and complete?
  • Does the invoice include the campaign name, a purchase order number (if the client uses them) and a clear due date?

If something was missing, fix it and resend. That alone solves a surprising number of late payments.

The follow-up schedule

A good rhythm is:

  1. A friendly reminder 3 days before the due date.
  2. A short note on the due date.
  3. A firmer follow-up 7 days after the due date.
  4. A final notice 14 to 21 days after the due date, mentioning late fees if your terms include them.
  5. A phone call if there's still no response.

Space matters. Messaging every day feels aggressive; waiting a month makes it look like you don't mind.

Template 1: Before the due date

Subject: Invoice INV-0012 due on 15 November > Hi Nimali, > > Hope the campaign is going well! A quick heads-up that invoice INV-0012 for the Summer Launch Reels (LKR 125,000) is due on 15 November. > > I've attached it again here for convenience. Let me know if you need anything else from me to process it. > > Thanks, > Kasun

This isn't chasing yet. It's a helpful reminder that also confirms the invoice arrived.

Template 2: On the due date

Subject: INV-0012 due today > Hi Nimali, > > Just a reminder that invoice INV-0012 (LKR 125,000) is due today. Payment details are on the invoice, which I've attached again. > > If it's already on its way, thank you, and please ignore this note. > > Best, > Kasun

Template 3: One week overdue

Subject: Overdue: invoice INV-0012 > Hi Nimali, > > I haven't yet received payment for invoice INV-0012 (LKR 125,000), which was due on 15 November. > > Could you let me know when I can expect it, or whether there's anything holding it up on your side? If it would help, I'm happy to send it directly to your accounts team. > > Thanks, > Kasun

Asking "is anything holding it up?" gives the client an easy way to tell you about an approval problem, which you can then help solve.

Template 4: Final notice

Subject: Final reminder: INV-0012 now 21 days overdue > Hi Nimali, > > Invoice INV-0012 (LKR 125,000) is now 21 days overdue. As set out in the terms on the invoice, a late fee of 2% applies from today. > > Please arrange payment by 12 December. If there's an issue with the invoice, reply and let me know so we can sort it out. > > Regards, > Kasun

Only mention late fees if they were in your agreed terms. Stay factual and calm: you're describing what was agreed, not making a threat.

When to pick up the phone

If email doesn't work after the final notice, call. A two-minute conversation often reveals the real reason: a missing purchase order, a finance team member on leave, or a cash-flow issue. Once you know the reason, agree on a date and confirm it by email.

If the client can't pay in full, a payment plan (for example two instalments over a month) is better than nothing. Put it in writing.

Keep it professional, always

A few rules make chasing easier:

  • Stay polite, even when you're frustrated. You may want to work with this client again, and the people in accounts are rarely the ones who decided to pay late.
  • Always include the invoice number, amount and due date. Make it easy to act on.
  • Reply in the same email thread, so the history is visible.
  • Keep your follow-ups in writing, even after a call.

Prevent late payment next time

The best follow-up is the one you never have to send:

  • Agree on payment terms before you start, in writing.
  • Ask for a deposit on larger projects or new clients.
  • Send the invoice the day the work is delivered.
  • State your late-fee terms on the invoice.
  • Ask up front who should receive invoices and whether they need a purchase order.

Let reminders run on their own

Sending these emails by hand works, but it relies on you remembering. PlanBrix can send payment reminders for you before and after the due date, apply late fees you've defined, and stop as soon as you record the payment. You get paid without writing the awkward emails yourself.

Put this into practice.

Projects, invoices, payments and reminders in one place. PlanBrix has a free plan, no card needed.