How to chase a late invoice without souring the relationship

A simple sequence

1. A few days before the due date. A short, friendly heads-up with the invoice attached. It catches the "I did not know it was coming" cases.
2. On the due date. "Just a reminder that invoice 1051 is due today." Plain and polite.
3. About a week late. Ask whether anything is holding it up: a missing PO, a wrong contact, a question about a line.
4. Two weeks late. Be direct about the amount and the date, and offer a call if there is a problem.
5. A month late. A firm final reminder, written so that it can stand on its own if it ever needs to be read by someone else.

What good wording looks like

Hi Sam, a quick note that invoice 1051 for $395.50 was due on October 14. If it has already been paid, please ignore this. If something is holding it up, tell me and I will sort it out.

• Name the invoice number, the amount and the due date every time.
• Make it easy to answer: one question, not three.
• Keep the tone the same as your usual emails with that customer.

Know when the problem is not the payment

If the customer disputes the work, more reminders will not help. Pause, ask what the concern is, and fix the invoice or the work first. A promise to pay is not a payment, and a forwarded screenshot is not a deposit, so record a payment only when the money has actually arrived.

Automate the nudges, not the judgment

In Invo.tax you can switch on reminders for a single invoice, choose a standard or gentle schedule, and pause or stop them whenever you like. Reminders stop when the invoice is paid, and the final one waits for your approval before it goes out. They are off until you turn them on, and they need outgoing email to be set up first.