How to ask a client to pay an overdue invoice

Many overdue invoices are caused by ordinary delays or oversight rather than an intentional refusal to pay — an email that arrived on a busy day, an approval nobody chased, or an invoice that never reached the accounts system. Some are deliberate, and you will not know which from the first silence.

That uncertainty is what should decide the tone of the first message. Writing it as though it were an oversight costs you nothing if you are wrong, and preserves the relationship if you are right. Keep the firm version for when the evidence gives you a reason.

Send the first one at three days, not three weeks

The most common mistake is waiting. A fortnight passes, the amount feels awkward to raise, and by the time you write, you are annoyed and it shows. Three days after the due date is early enough that nobody is embarrassed and late enough that it is clearly overdue.

Sending early also protects the relationship. A short note at day three reads as admin. The same note at day thirty reads as a complaint, however carefully it is worded.

What the first message should contain

Four things, and nothing else: which invoice, how much, when it was due, and how to pay it. Every extra sentence is somewhere for the reader to get lost.

Subject: Invoice INV-0042 — £1,800.00

Hi Sarah,

Just a quick note that invoice INV-0042 for £1,800.00 was due on 22 August. I imagine it has simply been missed.

You can pay using the details on the invoice, and I have attached another copy in case the first went astray.

If it is already scheduled, ignore this — and thank you.

Best,
Ahad

The last line is doing more work than it looks. It gives the client an exit that does not require them to admit fault, and it removes the need for you to sound apologetic anywhere else in the message.

Do not apologise for asking

“Sorry to chase” and “I hate to be a pest” feel polite. What they actually do is frame a legitimate request as an imposition, and they invite the reader to treat it as optional. You delivered work. Asking to be paid for it needs no apology.

Politeness comes from the assumption of good faith, not from shrinking. “I imagine it has been missed” is warmer than “sorry to bother you” and considerably firmer.

Escalate on a schedule, not on your mood

Decide the sequence in advance — a nudge at three days, a firmer note at seven, a final email at fourteen — and follow it. A schedule stops two failure modes at once: leaving it so long that resentment leaks into the writing, and sending three messages in a week because a different client just paid and you noticed.

It also gives you something neutral to point at later. “This is my third reminder” is a fact. “I have been chasing you for ages” is an argument.

When the polite version stops working

Three ignored emails is information. At that point the problem is not the wording, and a fourth carefully phrased message will not fix it. Pick up the phone, or move to the formal route — which for qualifying UK business-to-business commercial debts may include statutory interest and a fixed recovery charge.

What to do when a client still has not paid covers that escalation, and the three reminder templates are ready to copy.