estimate vs quote legally binding
Estimate vs Quote in UK Law: When Are You Legally Bound?
Here's the legal position in one breath: an accepted quote is a fixed-price offer that becomes a binding contract the moment the customer says yes - you can't put the price up afterwards because cable or timber jumped. An estimate is an informed approximation and isn't binding. But it's not a free pass either, and that second part is where tradespeople get caught.
Under the Consumer Rights Act 2015, where no price was fixed you may only charge a 'reasonable price'. So an estimate you've wildly exceeded can still be challenged - 'it was only an estimate, mate' won't always save you. This article is the legal-protection side of the question; if you want the general when-to-use-which explainer, that's elsewhere on the blog.
A quote is a fixed-price offer
When you send a quote and the customer accepts it, you've formed a contract at that price. If copper spikes 15% between acceptance and starting on site, that's your problem, not theirs - unless the quote itself says otherwise. There's no legal magic in the word 'quote', but courts and customers alike treat a clear, itemised, fixed figure as exactly what it looks like: an offer capable of acceptance.
The flip side: until it's accepted, you can withdraw or change it. That's the whole reason a validity line exists - it stops the offer hanging open indefinitely.
An estimate is an approximation - with a catch
An estimate signals 'this is my informed best guess, not a promise'. The customer can't hold you to the figure. But because no price was fixed, the Consumer Rights Act's reasonable-price rule kicks in: if you estimated around £2,000 and invoice £4,500 with no warning and no scope change, the customer can push back, and if it went to a dispute the question would be what a reasonable price for that work actually was - not what you fancied charging.
So an estimate protects you from price movement only if it's clearly an estimate and you keep the paper trail as things change.
Where material price swings bite
The last few years have taught every trade the same lesson: cable, timber and board prices can move faster than your job pipeline. A fixed quote issued in January can bind you to January prices for a job that starts in April. If you quote fixed prices weeks ahead of starting, price movement is your risk unless the document says otherwise.
How to draft an estimate that actually protects you
- ✓ Label it clearly at the top: 'Estimate - not a fixed price'
- ✓ Add a validity window - 14 or 30 days from the date on the document
- ✓ Add a materials-cost clause so supplier hikes pass through instead of eating your margin
- ✓ Confirm the scope in writing - what's included and, crucially, what isn't
- ✓ If anything changes on site, confirm the revised figure by message before carrying on
ESTIMATE - NOT A FIXED PRICE This document is an estimate based on the scope described above. It is not a fixed-price quotation. This estimate is valid for 30 days from the date above. After that we may need to re-price to reflect current material costs. Material prices are held for 14 days; beyond that, materials are charged at supplier invoice cost. Any change to the scope of work will be priced and confirmed in writing before additional work is carried out.
From the tools: My brother, a spark in Leeds, once gave a customer a verbal ballpark of 'about £3,200' for a partial rewire. Between that conversation and starting the job, his cable costs jumped hard - the wholesaler's twin-and-earth price alone moved enough to swallow around £400 of the job. The customer insisted the ballpark was the price, and because nothing was in writing, my brother ate it rather than fall out with a whole street of referrals. Every estimate he sends now is headed 'Estimate - not a fixed price' with a 14-day materials line under it. He's had to invoke it twice since, and both customers accepted the revised figure without a murmur - because it was there in black and white from day one.
Quick answers
Is a quote legally binding in the UK?
Yes, once accepted - at that point it's a contract at the stated price, and material rises are your cost to absorb. Until acceptance you're free to withdraw or amend it, which is exactly what a validity window is for.
Is an estimate legally binding?
No, but it isn't meaningless. Because no price was fixed, the Consumer Rights Act 2015 says you can only charge a reasonable price - so a bill miles above the estimate, with no warning, is open to challenge.
Can I charge more than my estimate?
Within reason, yes - that's what an estimate is for. The safe habit is telling the customer in writing before doing the extra work, so the higher bill never lands as a surprise.
How do I stop material price rises hurting me on an estimate?
Label the document as an estimate, give it a 14- or 30-day validity window, add a materials-at-invoice-cost clause, and confirm scope in writing. Those four lines shift the price-movement risk back where it belongs.
Send estimates and quotes with the protective wording built in - drafted from a voice note in seconds.
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