Client Won't Pay the Final Invoice? What Builders Can Do
The short answer
Check who the client is first: homeowner or business. Then chase in writing on a fixed timetable, and use adjudication (business) or small claims (up to £10,000).
- Check who the client is first. The Construction Act payment rules don't cover work on the client's own home. Developers, landlords and businesses: they apply.
- Business client, no pay-less notice? They must pay the notified sum by the final date.
- Adjudication decides in 28 days from referral; homeowner claims up to £10,000 go to the small claims track.
- Next time, keep the last payment small: a deposit, stage payments before each stage, every variation in writing.
The final invoice is the one most builders lose sleep over. The work is finished, your leverage has gone, and the client goes quiet or starts finding faults.
If your client won't pay the final invoice, you have more options than it feels like. Which ones depends on one question: who is the client? If a big final payment is stuck right now, book a free strategy call and we'll look at your paperwork with you.
First 48 hours: find the real reason
Before you send anything formal, find out why the money hasn't come. Call, don't text. Then write down what they said.
| What the client says | What it usually means | Your first move |
|---|---|---|
| "We're waiting on funds" | A cash problem, not a dispute | Agree a date or instalments in writing |
| "There are snags" | A quality complaint, real or used as a reason to delay | Ask for the list in writing, book a snagging visit |
| "That extra wasn't agreed" | A variation dispute | Send the written approval, or offer to split it out and get the rest paid |
| No reply at all | Avoidance | Start the timetable below the same day |
Pay the undisputed part first. If £2,000 of a £12,000 final account is in dispute, ask for the £10,000 now and deal with the £2,000 separately.
Which rules apply to your job
The Construction Act payment rules do not apply to a contract mainly about work on the client's own home. Everyone else is covered: developers, landlords, businesses and main contractors.
| Homeowner in their own home | Business, developer, landlord or main contractor | |
|---|---|---|
| Construction Act payment rules | Do not apply | Apply |
| Payment and pay-less notices | Only if your contract has them | Required by law |
| Right to suspend work | Only if your contract gives it | After at least 7 days' written notice |
| Adjudication | Only if your contract gives it | A right at any time |
| Statutory late payment interest | No (business debts only) | Base rate + 8%, plus £40–£100 per invoice |
| Where it ends up | Letter of Claim, then court (small claims up to £10,000) | Adjudication, or court |
These are the rules in England and Wales. Scotland and Northern Ireland have their own court processes, so check locally there.
Problems like this usually trace back to cash and contracts. The free 4-minute Construction Business Scorecard shows your weakest area first. Want someone to run valuations, variations and final accounts for you? See our commercial management service.
Still chasing your final invoice?
Book a free call with our team. We'll look at your contract, your notices and the fastest route to getting paid.
A 28-day timetable when a client won't pay the final invoice
This is our timetable, not a legal deadline. The point is to act on fixed days instead of waiting and hoping.
- Day 1: send the final account. Itemised, with every signed variation, photos of the finished work and the due date.
- Day 7: call, then email. Overdue money gets chased within 7 days. Friendly, and ask for a payment date.
- Day 14: formal letter. Amount, due date, what the contract says and, for a business client, statutory interest.
- Day 21: offer a meeting. A snagging visit, a payment plan or mediation. Write down what was agreed.
- Day 28: escalate. A Letter of Claim to a homeowner, or a notice of adjudication or suspension to a business client.
Keep everything in writing and dated. If it ends up in front of an adjudicator or a judge, your emails are the evidence.
Chasing a final account right now? Book a free strategy call and we'll look at your contract and paperwork with you.
If the client is a business, developer or landlord
On these contracts the law gives you real tools. Use them in this order.
1. Payment notices. The contract must provide for a payment notice no later than 5 days after each payment due date. If the client doesn't send one, you can send your own notice, and the sum in it becomes the amount due. The final date for payment moves back by the days of delay.
2. Pay-less notices. To pay less than the notified sum, the client must send a pay-less notice saying what they think is due and how it was calculated. Under the statutory Scheme it must arrive at least 7 days before the final date for payment. No valid pay-less notice, and the full notified sum must be paid.
Got one? Run the 5 checks on a pay less notice, and if you're a subcontractor chasing a main contractor, follow our day 0 to 28 plan.
3. When the final payment is due. If the contract says nothing, the Scheme makes it due 30 days after completion (or after your claim, whichever is later). The final date for payment is 17 days after that.
- Suspend work: if a sum due isn't paid by the final date, you can suspend after at least 7 days' written notice stating the grounds.
- Adjudication: refer the dispute at any time. The adjudicator decides within 28 days of referral (up to 14 more with your consent), and the decision is binding until the dispute is finally settled.
- Interest: statutory interest is 8% above the Bank of England base rate, plus £40 (under £1,000), £70 (£1,000 to £9,999) or £100 (£10,000+) per invoice, unless your contract sets its own rate.
- "Pay when paid": a main contractor can't hold your money because its client hasn't paid it, unless that client is insolvent.
Letting the pay-less deadline pass in silence. If the client misses it, write and say so: the notified sum is now due in full.
If the client is a homeowner
The Construction Act doesn't help you here. Your contract does, and so does consumer law, on both sides.
Under the Consumer Rights Act 2015 a homeowner can expect the work to be done with reasonable care and skill. If it isn't, they can ask you to put it right or for a price reduction, and they can rely on that against your invoice. If no price was ever agreed, they owe a reasonable price.
So the snag list is your fastest route to the money:
- Get every complaint in writing, with photos and the room or item.
- Fix real snags quickly and get the client to sign them off. (What you owe on defects after handover: how long a builder is liable for defects.)
- Put a price on anything you dispute and offer to deduct only that amount.
- Close the list in one walk-round if new snags keep arriving. See what to do when the snagging list never ends.
If they still won't pay, follow the court's pre-action rules for debts owed by an individual:
| Step | What the rules say |
|---|---|
| Letter of Claim | Amount, interest or charges, details of the agreement, how to pay. Enclose the Information Sheet, Reply Form and Financial Statement |
| Time to reply | 30 days from the date at the top of the letter |
| Court claim | Claims up to £10,000 normally go to the small claims track |
| Claim fee | £205 for £3,000.01–£5,000, £455 for £5,000.01–£10,000, 5% above £10,000 |
| Mediation | Disputed claims up to £10,000 get free court mediation, and you must attend |
Above £10,000, or where the client says the work is defective, take advice from a construction solicitor before you issue. For the wording, use our letter before action template.
Don't forget the retention
On commercial work, retention is the final payment you're most likely to lose by forgetting it. Typically 5% is held back: half comes back at completion and half after a defects period, usually 12 months.
- Put both release dates in your diary the day the contract is signed.
- Chase in writing on the day, with the completion or defects certificate attached.
- Price it in. On a £40,000 package, 5% is £2,000 waiting for a year or more.
If a late final payment has left you short this week, start with our 7-day cash plan for when you can't pay suppliers or wages.
Stop it happening on the next job
You can't control how a client behaves at the end. You can make the final payment too small to hurt. Get the money in before the work, not after.
Here is the example schedule from our Cash Flow & Margin Blueprint for a £120K refurb:
| Stage | % | Amount |
|---|---|---|
| On signing (deposit) | 15% | £18,000 |
| Before strip-out & first fix | 20% | £24,000 |
| Before second fix | 25% | £30,000 |
| Before finishes & decoration | 25% | £30,000 |
| Practical completion | 10% | £12,000 |
| Snagging signed off | 5% | £6,000 |
The most a client can hold back at the end is the last 15%, not the whole job.
- Written contract every time (e.g. JCT Minor Works or a homeowner contract), with the schedule attached.
- Each stage paid before it starts. No payment, no start.
- Long-lead items (kitchens, glazing, joinery) paid upfront.
- Every variation priced and agreed in writing before you do it, then added to the next payment.
The clients who argue about paying upfront are usually the same clients who pay late at the end. A clear schedule filters them out before they cost you money.
Clayton, a plasterer, now signs work with £5K upfront and staged payments. His first project after our call was £10K. Individual results, not typical or guaranteed.
The Cash Flow & Margin Blueprint
Deposits, stage payments, the UK rules that hit your cash, and a fill-in payment schedule.
Get the free guideWant a contract and payment schedule that keeps the last invoice small?
Book a free strategy call.
Before you chase your next unpaid invoice
This is general information on the rules in England and Wales as of October 2026, not legal advice. For a large or disputed sum, speak to a construction solicitor.
Before you go
- You know whether the client is a homeowner in their own home or a business
- The final account is itemised, with signed variations and photos
- Undisputed money has been asked for separately from the disputed part
- Every chase is in writing and dated, on fixed days
- The next contract has a deposit and stage payments due before each stage
