How to chase an unpaid invoice (UK): a step-by-step plan with messages you can copy

The job's finished, the customer was happy, and the invoice went out weeks ago. The money still isn't in.

Here's how to chase an unpaid invoice without falling out with the customer. Start friendly, get firmer on a set timetable, and put everything in writing. If that fails, send a final demand, then a letter before action, then use the formal routes.

In short

• Check your invoice first: right amount, right person, a clear due date.
• Send a friendly reminder the day after it's due, then a firmer one a week later.
• If they still don't pay, send a final demand with a fixed deadline.
• Next comes a letter before action: your last warning before a court claim.
• If the customer is a business, you can add late payment interest and a fixed sum on top.

How do you chase an unpaid invoice, step by step?

You chase an unpaid invoice in stages, each one firmer than the last, with a date on every step. The trick is to chase on a timetable, not when you happen to remember.

The law doesn't set these days. They're a sensible plan you can adjust. Here's a worked example for a sparky owed £3,000 by a shopfitting firm, with the invoice due on day 0.

That's how to chase an unpaid invoice in practice. Keep a note of every message, call and promise. If it ever goes to court, that record shows you tried to sort it out first.

What should you check before you chase?

Check that nothing on your side is holding up payment. A wrong invoice gives a slow payer the perfect excuse.

• The amount matches the quote, plus any extras (added work) the customer agreed.
• The person. It went to whoever pays the bills, not just the site manager.
• The due date is on the invoice, in plain words.
• Your bank details are on it and correct.
• Any notice. On construction work, check for a pay less notice (a formal notice that they plan to pay less, and why).

Got a pay less notice? Then you're dealing with a dispute, not just a late payer. Our guide to payment and pay less notices explains what to do.

How do you politely chase an unpaid invoice?

Send a short, friendly reminder the day after the due date, written as if it's been missed, not ignored.

Most late payers simply forgot, so keep it light.

Copy this and fill in the brackets:

Subject: Invoice [number]: payment reminder

Hi [name],

Just a quick reminder that invoice [number] for £[amount] was due on [date]. I've attached a copy.

Could you let me know when it'll be paid? If there's a problem with it, give me a ring on [number].

Thanks,
[your name]

Send it by email, and a short WhatsApp or text if that's how you normally talk. Keep the email as your written record.

What should a firmer follow-up say?

A firmer follow-up should say the invoice is now a week overdue and ask for a payment date. Then pick up the phone.

A quick call often gets a straight answer that emails don't.

Subject: Invoice [number]: now overdue

Hi [name],

Invoice [number] for £[amount] is now [number] days overdue. I haven't had a reply to my last email.

Please pay by [date], or let me know today when it will be paid.

Thanks,
[your name]

On the call, be calm and get a date. Then confirm it by email: "Thanks for the chat. You said it'll be paid by Friday 14th." That turns a promise into a record.

What is a final demand letter?

A final demand letter is a formal letter saying the invoice must be paid by a fixed date, or you'll take further action. It's the point where friendly chasing stops.

Give a clear deadline. Northern Ireland's government guidance says to give a date at least 7 days away, and that's a fair minimum anywhere.

Subject: Final demand: invoice [number]

Dear [name],

Invoice [number] for £[amount], dated [date], was due for payment on [due date]. Despite reminders on [dates], it remains unpaid.

Please pay the full amount to [bank details] by [deadline date].

If it isn't paid by then, I'll take further steps to recover the debt without more notice.

Yours sincerely,
[your name], [business name]

Only threaten what you're ready to do. An empty threat teaches a slow payer to wait you out.

What is a letter before action?

A letter before action is your last formal warning before you start a court claim. It says what's owed and the date you'll go to court if they don't pay.

It's also called a letter before claim. Northern Ireland's guidance says the court will expect you to try to sort it out first. It says your letter should include:

• the amount owed;
• what it's for;
• what you've already done to get it back;
• the date you expect payment.

Subject: Letter before action: invoice [number]

Dear [name],

You owe [business name] £[amount] for [work done] at [site address], under invoice [number] dated [date]. It was due on [due date].

We've asked for payment on [dates of reminders and calls]. It hasn't been paid.

If the full amount isn't paid by [date], we intend to start a court claim to recover it, plus interest and costs, without further notice.

If you dispute any part of this, please tell us in writing before that date and say why.

Yours sincerely,
[your name], [business name]

If the customer is a person or a sole trader, in England and Wales this letter must follow the Pre-Action Protocol for Debt Claims. That means a letter of claim sent by post with a statement of account, the protocol's information sheet, reply form and financial statement, and at least 30 days from the date of the letter for them to reply before you start a court claim. The template above, with its shorter deadline, is for business customers that are companies.

Not sure about the steps before a court claim? Get advice before you send this letter, especially if the customer is a person rather than a company.

What can you do if they still don't pay?

If the letter before action doesn't work, you can make a court claim for the money. You can also use the construction routes below, which are often quicker on a building job.

A court claim in England and Wales. You can claim online through GOV.UK. There's a court fee based on the amount you claim, and you may get it back if you win.

If the claim is 10,000 pounds or less and the customer disputes it, you'll be told to attend mediation. The court organises it, and it's free.

Scotland and Northern Ireland have their own systems. In Scotland, a simple claim under 5,000 pounds usually uses simple procedure. In Northern Ireland, claims up to 5,000 pounds can use the online Small Claims service.

Construction routes. On a construction contract, you can suspend work for non-payment. You must first give at least 7 days' notice saying why.

You can also refer a payment dispute to adjudication (a fast decision by an independent expert) at any time. Under the Construction Act, neither route applies to work on a home the customer lives in.

In Northern Ireland, the same right to suspend comes from Article 11 of the Construction Contracts (Northern Ireland) Order 1997.

Interest. If your customer is a business, you can charge late payment interest at 8 per cent plus the Bank of England base rate. You can also add a fixed sum of 40, 70 or 100 pounds, depending on the size of the debt. Our guide to working out late payment interest shows the sums.

The Small Business Commissioner may help if you're a small business with an unresolved payment dispute with a larger customer.

Can trade admin software chase quotes and unpaid invoices automatically?

Yes. Admin software can send the reminders for you on a set schedule.

That means a late payer gets chased on day 1 and day 7, even when you're on the tools.

The catch is tone and control. Before you switch it on, check these:

Nexley is one example: it chases quiet quotes and unpaid invoices on a schedule, and you approve before anything goes.

Where Nexley fits

Chasing is the job everyone means to do on Friday and never does. Nexley is the AI back office for UK trade firms. Five AI assistants do the office work overnight, and you approve each one from WhatsApp.

Nexley drafts the invoice the day the job finishes. Then it chases quiet quotes and unpaid invoices on a schedule, in a tone you'd be happy to have sent. You stay in charge: it drafts, and you sign off before anything goes.

See how it handles invoicing and chasing linked to Xero, or try it free for 7 days.

Common questions

How long can you chase an unpaid invoice?

In England and Wales, you usually have 6 years from when the debt was due to start a court claim. Northern Ireland also has a 6-year limit.

In Scotland, the debt can be wiped out after 5 years if it hasn't been claimed or acknowledged. Don't leave it that long, though: the older a debt gets, the harder it is to collect.

Can you charge interest on an unpaid invoice?

Yes, if your customer is a business. The Late Payment Act lets you add 8 per cent a year plus the Bank of England base rate, and a fixed sum on top.

Send a new invoice showing the interest. The Act doesn't cover homeowners, so only charge them interest if they agreed to a fair interest term before the job started.

When should you chase an invoice?

Chase it the day after it's due. Waiting a week or two only tells the customer your invoices can wait.

A friendly heads-up a few days before the due date helps too, especially on a bigger invoice. If no due date was agreed with a business customer, it counts as late 30 days after they got your invoice or you finished the work, whichever is later.

What if the customer is a homeowner?

The same steps work: reminder, follow-up, final demand, then a letter before action. What changes is the extra protection. In England and Wales, the letter before action must follow the Pre-Action Protocol for Debt Claims and give them 30 days to reply.

Late payment interest and the construction payment rules don't cover a homeowner's own home. So put stage payments and due dates in your quote before you start, and chase each one on time.

Sources

This page is general guidance, not legal advice. For a large or disputed debt, or before you start a court claim, get advice on your own case.

• Late commercial payments: charging interest and debt recovery (GOV.UK) (gov.uk)
• Make a court claim for money (GOV.UK) (gov.uk)
• Pre-Action Protocol for Debt Claims (Ministry of Justice) (justice.gov.uk)
• Court fees for money claims (GOV.UK) (gov.uk)
• Recover debts owed to you (nidirect, Northern Ireland) (nidirect.gov.uk)
• Make a court claim for money in Scotland (mygov.scot) (mygov.scot)
• Housing Grants, Construction and Regeneration Act 1996, section 112: suspending work for non-payment (legislation.gov.uk) (legislation.gov.uk)
• Housing Grants, Construction and Regeneration Act 1996, section 108: adjudication (legislation.gov.uk) (legislation.gov.uk)
• Construction Contracts (Northern Ireland) Order 1997, article 11: suspending work (legislation.gov.uk) (legislation.gov.uk)
• Limitation Act 1980, section 5: time limit for contract claims (legislation.gov.uk) (legislation.gov.uk)
• Office of the Small Business Commissioner (smallbusinesscommissioner.gov.uk)