SiteKiln gives you plain-English information, not legal advice. It's aimed at small UK construction businesses. Laws change and every job is different, so speak to a solicitor or adviser before you rely on this for a real dispute.
If a customer changes their mind mid-job, you're not automatically stuck doing extra work for free, and they're not automatically allowed to cancel without paying for what you've already done.
1. The short version
The key is to pin down variations in writing as you go, and if they genuinely cancel part-way through, you may be entitled to a reasonable sum for the value of work done (quantum meruit) even if the original contract doesn't spell it out.
2. Where you stand legally
- A variation is any agreed change to the original scope -- extra work, omitting work, changing materials, or altering design.
- There is no automatic right to extra payment just because circumstances changed; you usually need a contractual right to vary or a clear agreement about paying more.
- To be paid for extra work, you normally need to show:
- The extra work was not already included in the contract sum.
- The customer requested or clearly accepted the change.
- There was an express or implied promise to pay extra.
- Any notice or valuation procedures in the contract were followed.
- If the client cancels or changes their mind in a way that effectively ends the contract, you may have a claim on a quantum meruit basis -- "a reasonable sum for the work done".
- Quantum meruit is usually used where:
- Work has been done with no agreed price.
- Work was done outside the original scope at the client's request.
- A contract is unenforceable or has been terminated, but the client has still had a benefit from your work.
- In many cases, the contract price acts as a cap on what you can recover on a quantum meruit basis, especially in formal construction law settings.
- For domestic home-improvement contracts taken in the consumer's home or at a distance, there's usually a 14-day cooling-off period, but if they ask you to start during that period and then cancel, they can still be liable for the value of work done up to cancellation.
3. Work out what's actually changed
Get clear in your own mind whether this is:
- Extra work they now want (scope creep).
- A change of design / materials.
- A partial cancellation ("stop there, we don't want the rest").
- A full repudiation ("we're sacking you, we don't want you to carry on").
Ask the client to confirm in writing:
- What they want to change or stop.
- Whether they still want the rest of the original job.
- Whether they accept this may affect price and timing.
Check your paperwork:
- Does your contract or quote talk about variations, extras, or how changes will be priced?
- Does it say anything about cancellation or minimum charges?
Work out quickly:
- How much work you've already done and what it's worth.
- Costs and losses if you stop now (materials on site, restocking charges, labour already booked).
This tells you whether you're talking about a variation (same contract, changed scope) or a job that's effectively being cut short, where quantum meruit and cancellation rights start to matter.
4. Check your own position honestly
Look at the original deal:
- Was it a single fixed price for the whole job ("entire" contract), or clearly split into stages?
- Did you make casual promises like "we can change things as we go" that might be used against you?
Be real about what you can prove:
- Do you have any written agreement on how extras are charged (day rate, fixed price per item, etc.)?
- Have you been logging variations as you go, or just "we'll sort it at the end"?
Consider the cooling-off angle:
- If the contract was agreed off-premises or at a distance (phone/online), did you give the client proper cancellation information?
- Did they ask you in writing to start within the 14-day period?
If you've done a lot of work and they now want to scrap or massively change it, your realistic options are:
- Agree a fair extra/omission price and carry on.
- Agree to end the contract and invoice on a quantum meruit basis for what's done.
If you've done very little and they're inside the cooling-off period with no clear written start request, you may have to take it on the chin and treat it as a learning moment for future paperwork.
5. Offer a clear way forward
Put three things in writing to the client:
- What they've asked to change/stop.
- What that means for scope, programme and price.
- Their options (continue as planned, vary the job, or stop and settle up to date).
For extra work / design changes
- Price the variation and set it out clearly ("original scope £X, additional work £Y, new total £Z").
- Make it clear that the extra will not proceed until the variation is agreed in writing.
For partial cancellation ("stop there")
- Set out the value of work done to date on a reasonable basis (materials on site, labour, overheads).
- Explain that if they want to stop, you expect payment for work done and committed costs.
For full cancellation
- If they're within a 14-day cooling-off period and you've already started at their request, explain they may owe a proportionate amount for work already carried out.
- If they're outside any cooling-off period, treat it as a repudiation and look at a quantum meruit or damages-style claim for losses.
The tone you want is calm and factual: you're not blocking change, but you're not agreeing to lose money because they've changed their mind.
6. Send a pre-action style note if they refuse to pay for work done
If they've changed their mind, you've stopped work as requested, and they're now refusing to pay for what's already been done:
Cover the basics
- Original contract details and price.
- The date and content of their change-of-mind / stop instruction.
- The work you'd completed up to that point (with photos where possible).
- The reasonable value you're claiming for that work (labour, materials, etc.).
Explain the legal basis in plain English
- That you're not seeking the full contract price, only a reasonable sum for the value they've received (a quantum meruit basis).
Give them a deadline
"If I don't receive £[amount] within 14 days, I may start a small claim in the county court to recover this sum."
This keeps the door open to settlement but lines things up sensibly if you need to use small claims later.
7. Decide if you want to fight over it
Ask yourself:
- Is the amount worth the hassle and court fee?
- How strong is your evidence of what was agreed and what was done?
- Did you keep decent records of variations, instructions and progress?
Consider:
- If you pushed too many changes through verbally with "we'll sort it later", a judge may trim your claim.
- If the customer has had a clear benefit (partly completed works they've then built on), courts are often open to a quantum meruit claim.
Think about reputation and time:
- Sometimes a smaller, negotiated figure paid quickly beats chasing every last pound at small claims.
- If the number is high and your paperwork is decent, it's worth at least one serious written attempt to settle, then considering small claims using your 9.9 guide as the practical how-to.
8. When you need proper legal advice
Get advice from a solicitor or specialist if:
- The job is large and the change of mind would wipe out your profit or more.
- There's a formal written contract with complex variation provisions.
- You're looking at ending the contract and claiming for loss of profit as well as work done.
Legal help can:
- Check if you've actually got a good quantum meruit or damages claim.
- Help you frame offers and responses that line up with the Civil Procedure Rules.
- Stop you accidentally accepting a bad deal in a heated WhatsApp chat.
9. Common mistakes
- Letting scope creep with no paper trail -- doing "just a bit more" over and over without written variations is how you end up working a week for free.
- Saying "we'll sort the price later" -- courts like clear, upfront prices for extra work; vague promises are hard to enforce and can undercut a quantum meruit claim.
- Stopping work without clarifying terms -- if you down tools without confirming whether you're treating their change of mind as a cancellation and what you expect to be paid for, you weaken your position.
- Ignoring cooling-off rules -- not giving proper cancellation information on off-premises jobs can make it harder to get paid if they change their mind early.
- Assuming you always get the full contract profit -- in many cases you're looking at a reasonable value for work done and committed costs, not the whole margin you'd have made if the job ran to the end.
10. Who to contact
- Citizens Advice -- consumer problems -- guidance on building contracts, cancelling work and paying for work already done: 0800 144 8848 (free)
- Citizens Advice consumer service -- specialist line for disputes where a consumer has changed their mind or cancelled: 0808 223 1133 (free, England)
- Trade bodies / contract advisers -- organisations familiar with construction contract variations can help tighten up your processes (varies -- often paid or member benefit)
- Solicitor specialising in construction / contract law -- for higher-value jobs, complex contracts, or quantum meruit / loss-of-profit claims (paid)
11. Sources and legislation
- Consumer Rights Act 2015 -- Part 1, Chapter 4 (services: reasonable care and skill, repeat performance, price reduction). legislation.gov.uk/ukpga/2015/15
- Consumer Contracts (Information, Cancellation and Additional Charges) Regulations 2013 -- 14-day cooling-off period for off-premises and distance contracts, and liability for services started during cooling-off. legislation.gov.uk/uksi/2013/3134
- Supply of Goods and Services Act 1982 -- sections 13-15 (implied terms for services). legislation.gov.uk/ukpga/1982/29
- Quantum meruit -- common law principle: reasonable payment for work done where no price agreed or contract incomplete. Applied in construction cases including Serck Controls Ltd v Drake & Scull Engineering Ltd and Costain Ltd v Charles Haswell & Partners Ltd.
- Civil Procedure Rules Part 27 -- Small Claims Track procedures. legislation.gov.uk/uksi/1998/3132/part/27
12. Related guides on this site
- 9.1 Customer won't pay the final invoice
- 9.11 Customer demanding a refund -- when you have to and when you don't
- 9.13 Scope creep -- client keeps adding work and expects it for free
- 9.14 Client blaming you for a pre-existing problem
- 8.5 Writing quotes that protect you
- 8.6 Terms and conditions template -- domestic work
- 2.5 Variation orders -- protecting yourself
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