Guide
How to chase unpaid invoices
Written for UK sole traders and small businesses. Gentle first, firm when needed — and nothing here needs an awkward phone call.
The short answer
Send a short, friendly reminder the day after the invoice falls due, then a clearer one a week later, then a firm one at two weeks asking for a specific payment date. If it's still unpaid at around 30 days, send a formal letter before action. You can charge statutory interest and a fixed recovery cost on late commercial payments, and in England, Wales and Northern Ireland you generally have six years to pursue the debt.
The escalation ladder
The mistake most people make isn't chasing too hard — it's leaving it too long, then chasing once, angrily. Steady, predictable steps work better and cost you nothing in goodwill.
- 1
Day 1 after the due date
A friendly nudge
Assume it's an oversight, because most of the time it is. Keep it short, warm and easy to act on.
Hi Sam — hope the bathroom's settling in nicely. Just a gentle nudge that invoice #1042 for £480 was due yesterday. If it's already on its way, ignore me completely. Thanks!
- 2
Around a week overdue
A clear reminder
Still polite, but now state the facts plainly: the amount, the reference, how many days late, and how to pay.
Hi Sam — invoice #1042 for £480 is now 7 days overdue. Bank details are on the invoice, and I've attached a copy in case it's gone astray. Could you let me know when I can expect payment?
- 3
Around two weeks overdue
Firm and specific
Ask for a payment date rather than a reply. Mention that statutory interest and compensation apply to late commercial payments.
Hi Sam — invoice #1042 for £480 is now 14 days overdue. Please confirm a payment date by Friday. Late commercial payments carry statutory interest and a fixed recovery cost, which I'd rather not add.
- 4
Around 30 days overdue
Final notice before formal action
Neutral, factual, no anger. Give a deadline and say what happens after it. This is the last step before a letter before action.
Invoice #1042 for £480 remains unpaid, now 30 days past its due date. If payment is not received by 5pm on [date], I will send a formal letter before action and may begin recovery proceedings.
How long can you chase an unpaid invoice?
In England, Wales and Northern Ireland, most unpaid invoices are a simple contract debt, and you generally have six years from the date the debt became due to bring a claim, under the Limitation Act 1980. In Scotland the equivalent period is five years, under the Prescription and Limitation (Scotland) Act 1973.
If the client acknowledges the debt in writing or makes a part payment, the clock can start again from that point. That's one good reason to keep every reminder and reply in one place.
Read the law itself: Limitation Act 1980 · Prescription and Limitation (Scotland) Act 1973
How to calculate interest on overdue invoices
When another business pays you late, you can charge statutory interest of 8% plus the Bank of England base rate, unless your contract sets a different rate. You can also add a fixed sum for the cost of recovering the debt: £40 for invoices under £1,000, £70 for £1,000 to £9,999.99, and £100 for £10,000 or more.
The base rate has been 3.75% since 18 December 2025, so statutory interest is currently 11.75% a year. Always check the current Bank Rate before you invoice for interest, and see the GOV.UK guidance.
Late payment interest calculator
Uses statutory interest of 11.75% a year and the fixed recovery cost.
Enter an amount and the date the invoice was due to see what you could claim.
Sending a letter before action
A letter before action is the formal, final step before court. It isn't aggressive — it's simply clear. Send it once the friendly and firm reminders have run out, usually around 30 days overdue.
- · Your details and the client's, and the date.
- · The invoice number, amount, date issued and date due.
- · A short history of the reminders you've already sent.
- · Any interest and recovery costs you're claiming, shown as a total.
- · A clear deadline — commonly 14 days — and how to pay.
- · What happens next if the deadline passes.
Keep a copy, and keep the trail of everything you sent before it. If it ever does reach court, that record is the whole case.
For the full detail — every point the letter must cover, what to enclose with it, and how long to give them to reply — read our guide to writing a letter before action.
Common questions
How do I chase an unpaid invoice without damaging the relationship?
Chase early and lightly. A nudge the day after the due date reads as admin; a first chase three weeks later reads as an accusation. Keep the tone the same as the tone you used when you quoted the job.
How long can you chase an unpaid invoice in the UK?
Generally six years in England, Wales and Northern Ireland, and five years in Scotland — measured from when the payment became due. A written acknowledgement or part payment can restart that period.
How do I calculate interest on an overdue invoice?
Take the invoice amount, multiply by 8% plus the Bank of England base rate, divide by 365, and multiply by the number of days late. Add the fixed recovery cost of £40, £70 or £100 depending on the invoice size.
Do I have to charge interest?
No. It's your right, not an obligation. Many people mention it as a consequence without ever invoicing for it — which is often enough on its own.
What if the client disputes the invoice?
Stop chasing and deal with the dispute directly, in writing. Resolve the substance first; if it turns out the invoice stands, the chasing clock picks up from there.
This guide is general information about UK late payment, not legal advice. For a specific debt or dispute, speak to a solicitor.
Or let TactPay do the chasing
TactPay writes and sends these reminders for you, in your voice — gentle first, firm when needed — and keeps every message and reply in one place. You approve each one before it goes.