Quote or Estimate? Is a Builder's Quote Legally Binding?
You've got a piece of paper (or a PDF) with a price on it. Is it a quote or an estimate? Is it legally binding? And how long does it stay valid?
Homeowners mix these up all the time, and builders sometimes use the words loosely too. Getting them straight before you sign or pay a deposit saves a lot of grief later. This is practical guidance from a builder's point of view, not legal advice. For a dispute or a contract you're unsure about, speak to a solicitor or Citizens Advice.
Quick answer
- A quote (or "quotation") is usually a fixed price for a defined scope. Once you accept it, it can form part of a contract.
- An estimate is a best guess. The final bill can be higher or lower.
- Whether something is binding depends less on the word on the page and more on what was agreed, in writing, about the scope, the price and the terms.
- Quotes are often valid for 30 days, but only if the document says so. If it doesn't say, ask.
- Under the Consumer Rights Act 2015, work must be carried out with reasonable care and skill, at a reasonable price if none was agreed, and within a reasonable time (legislation.gov.uk).
Quote vs estimate: what's the difference?
Quote (quotation)
A quote should set out the work, the materials and a price you can hold the builder to for that defined job. If the scope stays the same, the price should stay the same. Changes (variations) need agreeing separately, preferably in writing with a price before the work is done.
Estimate
An estimate is an informed guess. It is useful early on, when drawings aren't finished or the builder hasn't opened anything up. It is not a fixed price. If your document says "estimate", "guide price" or "subject to survey", treat the number as provisional.
What if it doesn't say which it is?
Look at the wording:
- Fixed figures against a clear specification lean towards a quote.
- Lots of "allow for", "provisional sum", "approx" and "subject to" lean towards an estimate.
- A single round number with no breakdown is hard to enforce either way.
If you're not sure, ask the builder in writing: "Is this a fixed quote for the work described, or an estimate?" Keep the reply.
Not sure whether what you've got is a quote or an estimate? For £59 I'll read up to three documents for one job and tell you which parts look fixed, which are allowances, and what to pin down before you sign. Review my builder's quote, £59
Is a builder's quote legally binding?
On its own, a quote is an offer. It becomes binding when you accept it and there is agreement on the essential terms (what's being done, for how much, and the main conditions). That acceptance can be a signature, a clear email saying "please go ahead", or sometimes conduct (paying a deposit and letting work start).
In practice:
- The quote alone, sitting in your inbox, does not force either of you to proceed.
- Once accepted, the quote (plus any drawings, spec and contract conditions you both agreed) is usually what the price dispute turns on.
- A signed contract (for example the JCT Home Owner Contract) is clearer than a quote on its own, because it sets out variations, payment, insurance and what happens if something goes wrong.
Citizens Advice recommends getting a written contract and being clear about the price and how changes will be handled (Citizens Advice).
This is not legal advice. Contract law turns on the facts of your case. If money or unfinished work is at stake, get proper advice.
How long is a builder's quote valid?
Many quotes say "valid for 30 days" (sometimes 14, sometimes 60). That protects the builder against material price rises and a full diary, and it protects you from discovering the price has changed after you've planned around it.
If the quote doesn't say:
- Ask how long the price holds.
- Get the answer in writing.
- Don't assume last month's figure still stands after a long gap, especially if timber, steel or imported materials have moved.
Pressure tactics such as "this price is only good until Friday" are a red flag unless there is a real reason (a merchant's time-limited offer on a specific product). A fair quote should normally give you time to compare.
Can the price change after you've accepted?
Yes, but only in defined situations:
- You change the scope (different windows, extra sockets, a bigger opening). That should be a written variation with a price before the work starts.
- Provisional or PC sums in the original quote get replaced with actual costs. Ask how each allowance was worked out, and what happens if the real figure is higher.
- Hidden conditions nobody could see (rot, asbestos, ground that won't take the designed foundations). A fair contract explains how these are priced.
- An estimate, by nature, can move as the job becomes clearer.
What should not happen: the builder simply invoices more for the same defined work with no agreed change. If that is happening mid-job, collect everything in writing and get advice. Our example builder dispute page shows the kind of situation people bring to us.
What makes a quote stronger (and safer for both sides)
- Clear scope and exclusions
- Materials specified (makes, models, thicknesses), not "quality tiles"
- VAT stated (included, plus, or not registered)
- Programme and payment schedule tied to stages
- Deposit in the 5-10% band (or nil)
- A written variations process
- Insurance evidenced
- How long the quote is valid
Use the free builder quote checker on a single quote, or the comparison tool if you have two or three. The full how to check a builder's quote guide walks through every section.
The short version
A quote is an offer of a fixed price for a defined job; an estimate is a guess. Neither traps you until you accept. Once you accept, the wording, the scope and any contract you signed are what matter. Check how long the price holds, keep variations in writing, and don't treat a vague one-pager as a finished agreement.
Want a builder to read it before you accept?
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Frequently asked questions
Is a builder's quote legally binding?
A quote is usually an offer. It can become binding once you accept it and agree the essential terms. Whether it binds you depends on what was agreed in writing about the scope, price and conditions. This is not legal advice; for a dispute, speak to a solicitor or Citizens Advice.
What is the difference between a quote and an estimate in the UK?
A quote is generally a fixed price for a defined scope. An estimate is a best guess, so the final bill can change. If the document does not say which it is, check the wording for provisional sums and 'allow for' language, and ask the builder to confirm in writing.
How long is a builder's quote valid?
Many quotes are valid for 30 days if the document says so. If it does not say, ask how long the price holds and get the answer in writing. Do not assume an old figure still stands after a long gap.
Can a builder charge more than the quote?
For the same defined scope, a fixed quote should hold. The price can change if you alter the work, if provisional sums are replaced with actual costs, or if hidden conditions appear that nobody could have priced. Changes should be agreed in writing with a price before the work is done.
Does paying a deposit accept the quote?
Paying a deposit and letting work start is often treated as acceptance, along with a clear email saying please go ahead or a signed contract. Get the scope, price and payment terms clear before you pay.
Is this legal advice?
No. This is practical guidance from a builder's point of view about what to expect in a quote and contract. For a dispute or a contract you are unsure about, speak to a solicitor or Citizens Advice.
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