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In a dispute with your builder over money? What to do

By Alex Williams, director of Ty Parc Construction, a building contractor in Newport, South Wales · Last reviewed 21 October 2026

Start by putting the problem in writing and saying what you think is fair — and pay the part you don’t dispute. Under the Consumer Rights Act 2015 a builder must do the work with reasonable care and skill, and if no price was fixed, charge a reasonable one. A quote is a promise to do the work at that price unless you agreed to extras. If you can’t agree, use the builder’s trade body dispute service or mediation before going to court.

Your rights in brief (Consumer Rights Act 2015)

  • The work must be done with reasonable care and skill.
  • What the builder told you about the work can be binding.
  • A reasonable price if none was agreed.
  • Done in a reasonable time if no date was agreed.
  • If the work isn’t right, you can ask them to put it right, and if that doesn’t happen or isn’t possible, ask for a price reduction.

Step by step

  1. Gather the quote or contract, invoices, messages, photos, and a list of extras with dates.
  2. Write to the builder: what’s wrong, what you think is due, and what you want them to do, with a date to reply.
  3. Pay what isn’t in dispute so the argument stays about the disputed part.
  4. Get an independent opinion — another builder’s view, or a surveyor if it’s about quality.
  5. Use a dispute service: if the builder belongs to a trade body or scheme (TrustMark, FMB, NFB, or the new Approved Code once live — see our cowboy builders guide), use its complaints or dispute service; or try mediation.
  6. Small claims: claims up to £10,000 in England and Wales can go to the small claims track online via GOV.UK. Citizens Advice’s consumer service can help — find it on the Citizens Advice website.

If the dispute is about extras

Ask the builder when and how each extra was agreed. If it wasn’t agreed, you can dispute it; if it was agreed but no price was set, the price should be reasonable. Write down what you’ll pay for each and why.

If the builder stops work or threatens to

Don’t let pressure push you into paying what you don’t owe. Put your position in writing, check what your contract says about payment and suspension, and get advice before ending the contract yourself.

Builders: when a client won’t pay

List exactly what’s owed and how each part was agreed, and talk first. Then follow the steps in our letter before action guide and use the free letter generator.

Stopping it next time

Almost every money dispute is about what was agreed. Agree the price, each extra and each payment in writing as you go — our guide to building contracts covers what to put in writing at the start.

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