Quote vs estimate.What the difference means for a UK trade.

A quote, also called a quotation or a fixed estimate, is a promise to do the work at an agreed price. Once the customer accepts, that is the price, unless they agree to extra work or the price was obviously a mistake.

An estimate is your best guess. It gives the customer an idea of cost when you cannot fix the price yet, for example before you have opened up a wall. If the final bill is a lot more than the estimate, the customer can dispute it. The law says the price must be reasonable, without defining reasonable, so you have to agree it between you.

• Give a quote when you can see and measure everything the job needs. Customers prefer certainty and are more likely to accept.
• Give an estimate, and call it an estimate, when there are unknowns you cannot price yet.
• Or give a quote with provisional sums: a fixed price for what you can see, and clearly labelled allowances for what you cannot.
• Whichever you give, put it in writing and say what is excluded.

Most arguments about price come from scope that was never written down. Itemise the work, list exclusions, and if the job changes, send a revised quote for the customer to accept before you do the extra work. In Upheld a revised quote goes out as a new version on the same link, so there is always one agreed price.