5 emails you can copy
Five reminders for five points in time. Start with the first one and move down only if you need to. Replace every [BRACKET] with a real fact.
- Before the due dateSubject: Invoice [NUMBER] is due on [DUE DATE]Hi [FIRST NAME], A quick heads-up that invoice [NUMBER] for [AMOUNT] is due on [DUE DATE]. It is attached again, with the payment details at the bottom. If you need anything from me to pay it, tell me. [YOUR NAME]
- On the due dateSubject: Invoice [NUMBER], due todayHi [FIRST NAME], Invoice [NUMBER] for [AMOUNT] is due today. You can pay by [PAYMENT DETAILS]. Thank you for working with me. [YOUR NAME]
- Three days lateSubject: Invoice [NUMBER]: have you had it?Hi [FIRST NAME], I have not seen payment for invoice [NUMBER] ([AMOUNT], due [DUE DATE]). It may have slipped through. I have attached it again. Could you tell me when it will be paid? [YOUR NAME]
- Two weeks lateSubject: Invoice [NUMBER]: can we sort this out?Hi [FIRST NAME], Invoice [NUMBER] for [AMOUNT] was due on [DUE DATE] and is now [NUMBER] days late. I do not want this to become a problem between us. Is there something I should know? If you need to split the payment, tell me what you can pay and when. [YOUR NAME]
- After a missed promiseSubject: Invoice [NUMBER]: payment promised on [DATE]Hi [FIRST NAME], You told me on [DATE] that invoice [NUMBER] would be paid by [PROMISED DATE]. I have not received it. Please let me know today what has happened, and a new date I can rely on. [YOUR NAME]
What to avoid
- Do not apologise for asking to be paid. You did the work.
- Do not be sarcastic or write "as per my last email". It makes people defensive.
- Do not make threats in a first or second reminder.
- Do not send a reminder without the invoice attached. Make it easy to pay.
- Do not chase by email only. If a client goes quiet, try a short phone call too.
What the free tool adds
It is free. Use it if your customer is a UK business.

Late Payment Chaser (UK)
What you give it: The unpaid amount, the invoice date, and the due date if you agreed one.
What you get: What you can claim under UK late-payment law, worked out with a script and shown with official sources, and three reminder emails to send. UK business-to-business debts only. Not legal advice.
Free. It also works as a paste-in text in a chatbot; there the assistant does the arithmetic, so check its working.
Questions people ask
How polite is too polite?
Polite is fine as long as it is specific. Name the invoice, the amount and the date, and ask for a date to pay.
Should I send a reminder before the due date?
It is optional. Some people do, because it costs nothing and removes excuses. Others wait.
Should I call instead of emailing?
A call can work well after the second reminder. Follow it with an email so there is a written record.
What if they say they never got the invoice?
Send it again and ask them to confirm receipt. Then agree a new date in writing.
Can I charge interest?
That depends on your contract and your country. In the UK, see the page on late payment reminder emails for what GOV.UK says. Not legal advice.