Quote vs Estimate: What's the Difference and Which Protects You?

You ask three builders to price a new bathroom. Builder A sends a quote for £8,500. Builder B sends an estimate of £7,000–£9,000. Builder C sends a rough figure of "probably around £8,000, give or take". What is the difference, and which one gives you the most protection?

A quote is a fixed price

A quote is a fixed price for a defined scope of work. Once you accept it, the builder is legally obliged to complete the work for that price. If the job costs them more than expected, that is their problem — not yours.

For example, Builder A quotes £8,500 for your bathroom. Halfway through, they realise the pipework is more complicated than they thought. Unless you agree to a variation (a change to the original scope), the price stays at £8,500. The builder cannot come back and say "actually, it is going to be £10,000".

A quote is a firm offer. The builder has assessed the work and committed to a price. That commitment is legally binding.

The key is that the scope must be clear. If you later decide you want underfloor heating instead of a radiator, that is a change to the scope — and the builder can charge extra for it. But if the work stays as originally agreed, the price is fixed.

An estimate is a best guess

An estimate is an educated guess at what the work might cost. It is not binding. The final cost can be higher or lower depending on what the builder finds once work starts.

Builder B gives you an estimate of £7,000–£9,000. Once they start, they discover that the floor joists need reinforcement. The final bill comes to £9,500. Because it was an estimate, not a quote, they are within their rights to charge the higher amount — as long as it is reasonable.

The final cost should be within a sensible range of the estimate. If Builder B estimated £7,000–£9,000 and then charged £15,000 without your agreement to major changes, you would have grounds to challenge it.

When to ask for a quote vs an estimate

For work with a clear, fixed scope — like fitting a new kitchen, rewiring a house, or installing a bathroom — always ask for a quote. The builder can see what needs doing, so they can commit to a price.

For work where the full scope is not clear until they start — like repairing structural issues or investigating a leak — an estimate is more realistic. The builder cannot commit to a fixed price if they do not know what they will find.

If a builder insists on giving you an estimate for straightforward work, ask why. A professional builder should be able to give you a fixed quote for a standard bathroom or kitchen fit.

Get it in writing

Whether you get a quote or an estimate, make sure it is in writing. A verbal quote is technically binding, but proving what was said is nearly impossible if there is a dispute. A written quote — or better, a proper contract — removes all ambiguity.

A good written quote includes:

• A clear description of the work to be done
• The total price, including VAT if applicable
• What is included and what is not
• How long the quote is valid for
• Payment terms — when and how much

If the builder sends you an estimate, ask for a breakdown. What is the minimum cost? What is the maximum? What could cause it to increase?

Even with a fixed quote, you might request changes during the project — a different tile, a bigger shower. These are called variations, and the builder can charge extra for them. The key is that changes should be agreed in writing before the work is done. For more on this, see our article on written contracts for building work.

If you are a tradesperson trying to decide which to give, see our trade-focused guide on quote vs estimate: which should you give your customers. And if your builder has already charged more than quoted, see what to do when a builder asks for more money than the quote.

The bottom line

A quote is a fixed price and is legally binding. An estimate is a best guess and can change. For fixed-scope work, always ask for a written quote. For exploratory work, an estimate is reasonable — but make sure you understand the range.

The best builders put everything in a proper contract — ask yours if they use TradeContract. Try it free.