Quoting

Quote vs Estimate: What's the Difference? A UK Trade Guide

BuilderBuddy · 8 July 2026 · 7 min read

A customer asks you for "a quote." You send a figure. Three weeks later the job's grown arms and legs, the final bill is higher, and now they're refusing to pay the difference, waving your own message back at you.

This is where the difference between a quote and an estimate stops being pedantic and starts costing money. The two words are not interchangeable, and in the UK they carry very different legal weight. Get the wrong one on paper and you can be locked into a price that no longer covers the work.

Here's the difference, in plain English, and how to protect yourself whichever one you send.

Quote vs Estimate: The Simple Difference

A quote (short for quotation) is a fixed price for a clearly defined piece of work. You're saying: "This is exactly what I'll do, and this is exactly what it costs." Once the customer accepts it, that price is locked for both of you.

An estimate is your best-considered guess at what a job is likely to cost before the full scope is known. It's a guide, not a promise. The final figure can move up or down as the real work reveals itself.

The short version: a quote is a fixed price; an estimate is an educated approximation. Use a quote when the scope is certain, an estimate when it isn't.

Is a Quote Legally Binding in the UK?

Yes, in almost every case. Under UK contract law, a quote is treated as a firm offer. The moment the customer accepts it, in writing, by text, or simply by letting you start the work, a binding contract is formed at that price. That's reinforced by the Consumer Rights Act 2015, which expects the price agreed with a consumer to be honoured.

In practice that means you cannot quietly raise the figure later just because the job took longer than you hoped. If you quoted £2,400 and the customer said yes, £2,400 is the price, unless they agree, in writing, to a change. This protects the customer, but handled properly it protects you too: a clear, accepted quote is your strongest evidence if a payment dispute ever ends up in front of a judge.

Is an Estimate Legally Binding? Can the Final Bill Be Higher?

An estimate is not a fixed price, so the final bill can legitimately come in higher, but not by any amount you like. UK law expects the final charge to be reasonable. Where no fixed price was agreed, the Consumer Rights Act 2015 entitles the customer to pay a reasonable price, not whatever number lands on the invoice.

As a rule of thumb, courts and trading standards treat a final figure within roughly 10% to 15% of a genuine estimate as reasonable. Go materially beyond that and you need a good, documented reason, and you should have told the customer before the extra cost was run up, not after. The golden rule with estimates: the second you can see the price moving, put it in writing and get the customer's sign-off before you carry on.

When to Send a Quote and When to Send an Estimate

Most jobs make the choice for you. A few quick rules:

1. 1
   Scope is clear → send a quoteSupplying and fitting a specified radiator, hanging four internal doors, fencing a measured run. You can see the whole job, so commit to a fixed price and win on professionalism.
2. 2
   Scope is uncertain → send an estimateDamp of unknown extent, a rewire in an old property, anything hidden behind plaster or under floors. Give a considered figure, call it an estimate, and note what could change it.
3. 3
   Big job, unknowns you can isolate → quote plus provisional sumsQuote firmly for the parts you're sure of, and add clearly labelled provisional allowances for the unknowns. The customer sees a real price and knows exactly which bits might move.
4. 4
   Whichever you send, never mislabel itCalling an estimate a "quote" can trap you at a price that doesn't cover the work. Calling a quote an "estimate" makes you look unsure and invites haggling. Use the right word.

How to Protect Yourself, Whichever You Send

The difference between a quote and an estimate only holds up if it's written down properly. Whether you're fixing a price or giving a guide, the same essentials protect you:

Label it clearly. Put the word "Quotation" or "Estimate" at the top. Don't leave it to the customer to guess which one they're holding.

Define the scope in detail. "Supply and fit 12m of close-board fencing, 1.8m high, concrete posts and gravel boards," not "fencing." If it's not written down, it's not in the price, and that's where arguments start.

List your exclusions. Skip hire, scaffolding, making good, decorating after. If you're not doing it, say so. Exclusions protect you as much as the scope does.

Add an expiry date. Material and labour costs move. Thirty days is standard. A quote with no expiry is an open-ended liability.

Show VAT properly. If you're VAT-registered, break out the net, the VAT and the gross as separate lines. Never bury it.

The Bottom Line

A quote fixes the price; an estimate guides it. A quote is binding the moment it's accepted; an estimate must still be reasonable and can only move within sensible limits, with notice. Choose the right one for the job, label it clearly, write the scope down properly, and you'll rarely end up arguing over a final bill.

Do that consistently and the paperwork stops being a risk and starts being one of the strongest reasons a customer picks you.