An unpaid invoice: the three chases, and what comes after

The invoice went out, the due date passed, nothing happened. This is the moment people write either an over-polite message or a curt one, and both work badly.

Start with something that completely changes how the first message should be written.

Most late invoices are not refusals to pay

Out of ten late invoices, roughly one is a client who will not or cannot pay. The other nine are administrative accidents, and they are always the same ones:

• the invoice landed in a junk folder;
• it went to the person you worked with, who is not the person who pays;
• a reference is missing, a purchase order number, a delivery note, without which accounts process nothing;
• the person who approves it has been on leave for three weeks;
• the client fully intends to pay and simply forgot, which is extremely ordinary.

None of those nine calls for firmness. They call for information. Which is why a first message written as a reprimand costs you something for nothing: it puts somebody who did nothing wrong on the defensive, and makes everything after it harder.

Chase 1, at day three to seven: the neutral one

One sentence, the invoice attached, and the assumption that it never reached you.

Hello, I'm resending invoice 2026-084 in case it slipped past. Have a good day.

What not to write, and what everybody writes instinctively: "I still haven't received your payment". It is true, it sounds like an accusation, and nine times out of ten the accusation is aimed at somebody who never saw the invoice.

Attach the file again. Do not say "as agreed", do not send a link: the attachment removes half the causes on the list above in one second.

Chase 2, at day fifteen: the one almost nobody sends

It is the most effective of the three, and it is the one people skip, because it does not ask for money.

Hello, is there anything missing from my side for this invoice to be paid? A purchase order number, a reference, somebody else I should send it to?

It turns a silence into information. A question about what is blocking gets an answer when a demand for payment does not, because it is easy to deal with: the client does not have to deliver bad news, they just have to tell you what is missing.

And what it brings back is often the whole solution. "It needs to be addressed to the holding company, not to me." "Our accounts run payments on the 15th only." "I need a PO number on it, here it is." Three weeks of silence explained in one line.

This is also the moment for a phone call, if you have the number. Two minutes on the phone beats three emails, for the same reason: somebody on the phone tells you what is blocking, whereas an email requires them to write it down.

Chase 3, at day thirty: a date and a consequence

Here you stop assuming an accident. The message changes character, and two things have to be in it.

Hello, invoice 2026-084 has been overdue since 15 July. Without payment by the 30th I will pass the matter to collection and apply the late payment terms set out in the quote.

A specific date, not "as soon as possible". A vague deadline is not a deadline, and it postpones itself indefinitely.

A consequence you will actually apply. This is the part that matters. A threat you do not follow through on costs you more than silence: it teaches the client that your deadlines mean nothing, and the fourth chase will carry no weight at all.

And always: no anger, no apology. Anger shifts the subject onto the relationship, which is not the subject. Apology ("sorry to bother you with this") makes the debt sound negotiable, which it is not.

After the three chases

Two steps, in this order, described for what they are rather than for their legal machinery.

A formal written demand, sent by a method that proves delivery. It is not a legal action: it is a dated request whose sending and receipt you can prove. A great many cases settle at this point, precisely because it signals that what comes next is serious.

Then, depending on the amount, most jurisdictions have a short small-claims route that needs no solicitor.

Check what applies where you and your client are before acting, including any statutory late-payment interest or fixed recovery charge you may be entitled to between businesses. Those rules, rates and thresholds differ by country and change over time, this article is not legal advice, and an invoice is a poor place to be wrong.

Should you keep working?

No, and there is one rule: say so before you stop, not after.

A supplier who quietly stops working looks like a supplier who abandoned the project, including to a client who owes them money. One sentence does it, and it is factual: "I'm putting the job on hold pending payment of invoice 2026-084, and I'll pick it straight back up once it clears."

It is also the only defensible position if the matter goes further: you gave notice, in writing, and the client had the choice.

What prevents nine out of ten of these

One sentence, and it is worth the rest of the article: the balance is due at the moment the client collects their work, never after.

An invoice issued after delivery has no leverage behind it: the file is with the client, the site is live, and all they owe you is goodwill, which runs on a forty-five-day fuse. The same sum asked for at handover needs no chasing, because there is no delay.

That is the subject of deposit, balance, delivery, and it is the only place a late invoice is really dealt with: before it exists.

Frequently asked questions

How do you chase an unpaid invoice without souring the relationship?

By assuming an accident in the first message rather than a refusal. Out of ten late invoices, nine are administrative: wrong recipient, missing reference, somebody on leave. A first message that reproaches puts somebody on the defensive who did nothing wrong.

How long should you wait before chasing an invoice?

Three days to a week for the first, neutral, with the invoice attached. Fifteen days for the second, which asks what is blocking. Thirty days for the third, which carries a date and a consequence.

Which chase actually works best?

The one that does not ask for money: "is there anything missing from my side for this invoice to be paid?" It is easy to deal with, so it gets an answer, and that answer is often the entire solution.

Should you stop working when an invoice is unpaid?

Yes, and you should say so before you stop. A supplier who quietly stops working looks like one who abandoned the project, even to a client who owes them money.

What do you do after three chases with no reply?

A formal written demand sent by a method that proves delivery, then a short small-claims route depending on the amount. Check what applies where you and your client are, because the rules and rates differ by country and change; this is not legal advice.