Quote vs Estimate: What Is the Legal Difference?

A customer asks for a price, you send a number, and three weeks later they're holding you to it — even though the job grew. Sound familiar? The words quote and estimate get used interchangeably on most kitchen tables, but in law they can mean very different things. Get the wording wrong and you could be locked into a price that no longer covers your costs.

This guide breaks down the practical and legal difference, when each one becomes binding, and how to word your documents so you stay protected and still win the work.

Quote vs Estimate: The Core Difference

The simplest way to think about it:

• A quote is a fixed price. You're saying: this is what the job will cost. Once the customer accepts it, it generally forms part of a contract and you're expected to honour it.
• An estimate is your best, honest guess. You're saying: based on what I can see, it's likely to cost around this. It's not a firm commitment, and the final bill can reasonably differ.

That difference matters most when things go wrong. If you quote £1,200 to rewire a flat and you hit problems behind the plaster, you usually can't just bump the price — you committed to a figure. If you estimated £1,200 and were upfront that it was an estimate, you have far more room to charge for the extra work.

The label on the document isn't the only thing that counts, though. A court will look at what was actually agreed and how a reasonable customer would have understood it. Calling something an "estimate" while behaving as if it's a fixed price won't necessarily save you.

When a Quote Becomes Legally Binding

A quote typically becomes binding once the customer accepts it and you both intend to be bound — the basic ingredients of a contract. In practice that means:

• You set out a clear price and scope.
• The customer agrees to it (verbally, in writing, by signing, or by letting you start the work).
• Both sides intend it to be a deal, not a casual chat.

Once that's in place, you're generally on the hook for that price for the work described. You can't quietly inflate it later just because you underpriced.

The protection cuts both ways. A signed, dated, clearly scoped quote is also your best defence if a customer tries to wriggle out, dispute the figure, or claim you promised extras for free. Whatever you agreed in writing is what you can point to.

Tip: Always put a validity period on a quote — for example, "valid for 30 days". Material and labour costs move, and you don't want a customer accepting a six-month-old price after your supplier prices have jumped.

When You Can Charge More Than the Estimate

If you've given a genuine estimate, you can usually charge more than the figure — but not by any amount you fancy. The general expectation is that the final cost stays reasonably close to the estimate. A modest overrun is normal; doubling the price without warning is asking for a complaint or a refusal to pay.

The safest approach is simple: the moment you realise the job is heading past the estimate, stop and tell the customer. Explain what's changed, what it now looks like, and get their go-ahead before you carry on. Most disputes aren't about the extra cost itself — they're about the customer feeling ambushed by a bill they never saw coming.

If the work changes scope entirely (you find rot, asbestos, a buried problem), that's usually a variation. Price it separately, get sign-off, and keep it documented. For a deeper look at structuring the money side, see deposits and staged payments.

How to Word Quotes and Estimates Properly

Whichever you're sending, clarity is what protects you. A good document should make it obvious which it is and exactly what's covered.

Include:

• The word "Quote" or "Estimate" clearly at the top — don't leave it ambiguous.
• A detailed scope — what's included, and just as importantly, what isn't.
• A breakdown of labour, materials and any allowances.
• Exclusions and assumptions — for example, "price assumes existing pipework is reusable" or "excludes making good of plasterwork".
• VAT treatment — show clearly whether the figure includes VAT.
• A validity period and your payment terms.
• A note on variations — that extra or unforeseen work will be priced and agreed before proceeding.

Those exclusions and assumptions are where most trades lose money. If you don't write down what you haven't allowed for, a customer can reasonably argue it was part of the deal.

The estimate-then-quote approach

Plenty of trades use a sensible two-step process: give a rough estimate early to qualify the customer and set expectations, then survey properly and issue a firm quote before any work starts. It manages expectations without committing you to a price before you've seen what you're dealing with. There's more on getting the firm version right in how to price a job for profit.

Why Speed and Consistency Matter as Much as the Wording

The best-worded quote is useless if it lands two weeks late. Customers tend to go with whoever responds first and looks most professional, so getting a clear, properly worded document out quickly is half the battle for winning the job.

That's where doing it on paper or off the cuff lets you down. Hand-written estimates with no exclusions, prices texted over WhatsApp, no record of what was agreed — that's how disputes start and how money leaks out.

A job-management system like Gaffer lets you build quotes and estimates from reusable templates, so every one goes out labelled correctly, with your standard exclusions and terms already baked in. The customer can accept online, the agreement is timestamped and stored, and it flows straight through to invoicing — so the price you agreed is the price you bill, with far less admin and far fewer arguments.

FAQs

Is an estimate legally binding in the UK?

Generally no — an estimate is an informed guess, not a fixed commitment, so the final cost can reasonably differ. But you're still expected to keep it broadly accurate and to flag significant overruns before carrying out the extra work. Always check the current consumer rules, as your obligations can depend on the circumstances.

Can a tradesperson charge more than the quoted price?

If it was a genuine quote (a fixed price) that the customer accepted, you usually can't charge more for the agreed work — you committed to that figure. You can only charge extra for clearly separate or unforeseen work that you've priced and agreed with the customer before doing it.

What's the difference between a quote and an estimate for VAT?

The difference is about whether the price is fixed, not about VAT itself. Whichever you send, state clearly whether the figure includes or excludes VAT, as confusion over this is a common cause of payment disputes.

Should I send a quote or an estimate?

Send a quote when you've seen the job and are confident in the scope, so the customer gets price certainty. Send an estimate when there are unknowns you can't price accurately yet — then follow up with a firm quote once you've surveyed properly.