Can I charge more than my quote? When a tradesperson's final invoice can be higher, and when it cannot

Not unless the customer agrees to the change. A quotation is normally a fixed price, and under section 50 of the Consumer Rights Act 2015 the price information you give a householder becomes a term of the contract. A change to it "is not effective unless expressly agreed between the consumer and the trader". So the final invoice can be higher than the quote only for work or cost the customer said yes to, and the safe time to get that yes is before you do the work.

Quote, estimate, or no price at all

Which of the three you gave decides how much room you have.

A quote. Business Companion, the government-backed trading standards guidance site, puts it in one line: "A quotation is normally a fixed price whilst an estimate is generally a rough guess of what the work would cost." It also says that information given to a consumer is binding where they rely on it, and that "This will include quotations".

An estimate. The bill can differ from the figure, but not without limit. Business Companion says that where the price is not agreed beforehand it must be reasonable, and that this will typically be judged against the prices other similar traders might have charged.

No price. Section 51 of the Act covers a contract that does not expressly fix a price or say how it is to be fixed. The customer must then pay "a reasonable price for the service, and no more", and what is reasonable "is a question of fact". In practice that means an argument about what other firms charge.

For a job agreed at the customer's home there is a further rule. Before the customer is bound, regulation 10 of the Consumer Contracts Regulations 2013 requires you to give the information in Schedule 2, which includes "the total price" of the work "inclusive of taxes", or, where the price cannot reasonably be calculated in advance, the manner in which it is to be calculated. Section 50 of the Act then treats that information as a term of the contract. Our guide to writing a quote shows where each item goes.

Four reasons the bill goes up

Two of these need a little more.

The hidden problem. Section 50 says what you told the customer is subject to "anything that qualified it and was said or written to the consumer by the trader on the same occasion". A line in the quote such as "repairs to the floor found to be defective once the bath is out are not included and will be priced before we do them" is that kind of qualification. It does not set the price of the repair. It tells the customer the fixed price stops there, and you still need their yes to the extra figure.

Dearer materials. A clause saying "prices may change" will not rescue you with a householder. Schedule 2 of the Act lists two kinds of term that may be regarded as unfair. One gives the trader "the discretion to decide the price payable" after the consumer is bound, where no price or way of working it out was agreed. The other permits a price increase "without giving the consumer the right to cancel the contract if the final price is too high". If material prices worry you, shorten the time the quote stays open instead. Our terms and conditions template uses 30 days.

One job, four changes

A firm quotes a householder £4,800 including VAT for a bathroom refit, agreed at her home. The quote carries the floor line above. Four things then happen.

The final invoice is £4,800 + £360 + £285 = £5,445. The other £470 (£140 + £330) is the firm's cost of quoting a fixed price, and it stays with the firm.

Run it again with nothing in writing. The floor repair and the towel rail were discussed on site, the customer remembers it differently, and she pays £4,800. The firm is now £645 short on those two items (£360 + £285) and has to prove a conversation. The work was the same. All that separates the two outcomes is a pair of text messages.

How to make an extra stick

1. Stop before you start the extra work.
2. Send the price in writing. A text or email is enough.
3. Wait for a yes in writing. Business Companion's advice is "to record all changes in writing".
4. Put each agreed extra on the invoice as its own line, with the date it was agreed.
5. Keep the messages with the job file. Section 5 of the Limitation Act 1980 allows six years for a claim on a simple contract, so that is how long the proof may be needed. Our guide to how long to keep job records has the dates.

A message you can copy:

Hi [name], with the old bath out we have found [the problem]. Putting it right will cost £[amount] including VAT and adds [time] to the job. Shall we go ahead? Please reply yes or no. We will not do anything extra until you say.

Business customers

The Consumer Rights Act and the Consumer Contracts Regulations protect consumers. With a business customer, what counts is the quote and the terms they accepted. Write "plus VAT" on the quote if you mean it, and put your rule for extras in your terms, because no statute will supply either for you.

If the customer will not pay the higher bill

Sort the invoice into what was agreed and what was not. For the agreed part you are owed the money, and the route is the same as for any unpaid invoice: our guide to what to do when a customer won't pay sets out the steps and the court fees. For the part nobody agreed, the quote is the price. Offering to take it off the bill is usually cheaper than arguing for it.

Overlyft is an AI agency for small firms. It can set up an AI Quote Writer that drafts each quote from your notes with a line stating what is excluded, and you check it before it goes to the customer.

This is general information, not legal advice. For a large contract, or a job where the price depends on what you find, ask a solicitor to check your terms.