How To Chase An Unpaid Invoice

Chase in a fixed sequence and escalate on a schedule rather than on how annoyed you are: a polite reminder the day after the due date, a firmer follow-up at 7 days with the terms restated, a formal demand at 14 to 21 days setting out the statutory interest and compensation you’re entitled to, then a letter before action. Most invoices get paid in the first two steps. The point of a written sequence is that you never have to decide what to do next, and by the time you reach the end you’ve built a paper trail a court would recognise.

Before you chase, check your own paperwork

Half of all “they won’t pay” situations are actually “they can’t process it”.

Did the invoice actually arrive, at the right person, with a PO number if they need one? Does it show a payment due date, an actual date rather than “30 days”? Are the bank details on it and correct? And is there a complaint about the work you haven’t been told about yet, because a silent customer is sometimes an unhappy one.

Sorting an admin problem takes ten minutes. Sorting a legal one takes months. And you can’t credibly escalate on an invoice that never landed.

The sequence

Day 1 after the due date: polite reminder

Short, friendly, assume it’s an oversight. Attach the invoice again. Ask them to confirm a payment date.

This gets a surprising number of invoices paid and costs you nothing in goodwill.

Day 7: firmer follow-up, email and phone

Restate the terms and how far past due it is now. Ask a direct question: when will this be paid? Get a date and a name.

The phone call is the bit that matters. Email is easy to ignore. Someone who has verbally committed to a date is far more likely to pay it. Then follow the call with an email confirming what was agreed, because that’s your record.

Day 14 to 21: formal demand

Now the register changes. In writing, set out the invoice number, date, amount and due date, how many days overdue it is, and that the debt now carries statutory interest and fixed compensation under the Late Payment of Commercial Debts (Interest) Act 1998 if it’s a commercial debt. Work the figures out and show them. Give a deadline, usually 7 days, and say what happens if it passes.

Putting the entitlement in actual numbers is usually the moment things move. How to charge late payment interest has the rate and the calculation.

Day 30ish: letter before action

The formal step before court. It has to make clear it’s a letter before action, set out the debt and the basis for it, state what you’ll do if it isn’t paid, and give a reasonable deadline, normally 14 days.

On a business debt this is often the last thing you ever send. It signals you’ll actually issue a claim rather than just being annoyed about it.

After that

Roughly in order of cost: mediation or a negotiated settlement, which is often quicker and cheaper than being right. Money Claim Online for straightforward debts. A debt recovery agency, whose fee may be claimable as reasonable recovery costs. Or a construction adjudication, if it’s a construction contract in scope of the Construction Act, which is fast and built for exactly this.

Two extra levers on construction work

If the job is a construction contract covered by the Construction Act, which means commercial or subcontract work rather than a homeowner’s own home, you’ve got tools an ordinary supplier hasn’t.

Suspension comes first. Where a notified sum hasn’t been paid, section 112 lets you suspend any or all of your obligations after at least seven days’ written notice stating the grounds. You can recover the reasonable costs of doing it, and the time doesn’t count against your contractual deadlines.

Adjudication is the other one: a statutory right to a binding decision on a short timetable instead of waiting on the courts.

Both carry procedural traps and both are serious moves. Take advice before using either on a job of any size. Construction Act payment terms explains what’s in scope.

Worked example

A £3,200 invoice to a commercial customer, 30-day terms, nothing on the due date.

Day 1, reminder email with the invoice reattached. No reply. Day 7, you ring. They say it missed the payment run and will go on the next one in a fortnight, so you email to confirm that.

Day 21, still nothing. Formal demand: £3,200 outstanding, 21 days overdue, statutory interest at 11.75% running at about £1.03 a day, plus £70 fixed compensation, payment inside 7 days.

Day 26, paid in full.

Three emails and one phone call, on a schedule. The demand worked because the earlier steps had built a record and the figures were specific rather than vague.

Common mistakes

Going quiet. The most common one and the most expensive. An invoice nobody chases reads as an invoice nobody needs paid.

Escalating on temper. Going straight to threats on day two wrecks a relationship you might want and looks unreasonable if a judge ever reads it back. A schedule takes the feeling out of it.

Not confirming calls in writing. A verbal promise you can’t evidence is worth very little later on.

Never mentioning the entitlement. Statutory interest and the £40, £70 or £100 fixed sum exist on commercial debts. Most trades never bring them up at all.

Leaving it too long. Under the Limitation Act 1980 you generally have six years in England and Wales to bring a claim on a simple contract debt. The practical window is far shorter than that. How long you can chase an unpaid invoice covers it.

Chasing an invoice with a genuine problem on it. Wrong amount, missing PO, wrong company name. Fix it and reissue rather than escalating something they were always going to bounce.

Do this in FieldHive

Chasing is much easier when the invoice was right to begin with. Build a clear invoice with a real due date, correct details and optional statutory late-payment interest, free in your browser. When several invoices are outstanding, a statement of account with an ageing summary puts the whole position on one page, which is a lot harder to ignore than another copy of one invoice.

Aid, not advice

This guide sets out a practical chasing sequence and the entitlements behind it. It is not legal advice. Debt recovery, suspension and adjudication all carry procedural risk. For a disputed or high-value debt, take advice before escalating.

*Legislation and figures checked August 2026: Late Payment of Commercial Debts (Interest) Act 1998; Housing Grants, Construction and Regeneration Act 1996 s112; Limitation Act 1980 s5.*