Binding versus non-binding, UK and US rules, and wording you can copy for both
A quote is a fixed price that binds you once the client accepts it. An estimate is your informed guess at the likely cost, and it can change. In the UK, quote and quotation mean the same thing, and Citizens Advice notes that a quote is sometimes called a fixed estimate, which shows that the heading on a document matters less than what it says. In the US, estimate, bid and quote are often used loosely, and that is where many price disputes start. What decides whether you are held to a figure is what you wrote, what you left open and what the client relied on. Below are the UK and US rules, how far a final bill may move from an estimate, when to send which, and wording you can copy for both.
What is the difference between a quote and an estimate?
A quote says what the job will cost. An estimate says what it will probably cost. UK council consumer advice puts it this way: an estimate may vary because it gives a general outline of the work and a guide price, while a quotation is a fixed and binding price for specific work (Pembrokeshire County Council, Supply of services: your consumer rights). The practical differences follow from that.
Price: a quote gives one fixed amount for a defined scope. An estimate gives an expected amount or a range, such as £2,000 to £2,600 or $2,500 to $3,300
Binding: an accepted quote binds you to the price and the scope. An estimate sets an expectation, and the final price may differ within what you said and what is reasonable
Detail: a quote needs a precise scope, quantities and exclusions. An estimate can work from a short description, a photo or a phone call
Timing: estimates come early, for budgeting and shortlisting. Quotes come after a site visit, a brief or a specification
Validity: a quote carries a date until which the offer stands. An estimate usually lists what could move the price instead
Changes: under a quote, extra work needs the client's agreement before you do it. Under an estimate, you warn the client before the total goes past the figure or range you gave
Is an estimate legally binding?
Not as a fixed price, but it is not meaningless either. In the UK, section 50 of the Consumer Rights Act 2015 treats anything a trader says or writes to a consumer about the service as a term of the contract if the consumer took it into account when deciding to go ahead. Section 50(2) makes that subject to anything that qualified the statement and was said or written on the same occasion, or to a change both sides expressly agreed. So an estimate that reads £2,400, may rise by up to 10 percent if the plaster needs repair, is read together with that condition, and you are held to that frame. A caveat you only mention when the bill arrives does not count unless the client agrees to it. Where the contract does not fix a price or say how it is worked out, section 51 says the consumer must pay a reasonable price and no more. These sections protect consumers. With business clients the terms you agree decide the matter, so write the assumptions and the tolerance into the estimate itself.
Is a quote legally binding?
Yes, once the client accepts it. Citizens Advice tells UK consumers that a trader cannot charge more than the quoted price unless the trader explained that extra work was needed and the customer agreed to pay more, or the price in the quote was an obvious mistake. A rise in the trader's own costs after the quote is not a reason to charge more. Before acceptance, the position depends on where you are and what you sell. In US contract law, an offeror can typically withdraw an offer before acceptance unless the parties have created an enforceable option contract (Cornell Law School, Wex: offer). Goods are the exception. Under UCC § 2-205, a merchant's signed written offer to sell goods that gives assurance it will be held open cannot be revoked for lack of consideration during the time stated, or for a reasonable time if no time is stated, and never for longer than three months. Article 2 of the UCC applies to transactions in goods (UCC § 2-102), so this rule reaches a quote for materials or equipment, not a quote for labour alone. A valid-until date on a signed US quote for goods can therefore commit you to hold the price until that date, up to three months.
How much can a final bill differ from an estimate?
There is no general percentage in UK law. Section 51(3) of the Consumer Rights Act 2015 says that what is a reasonable price is a question of fact, and Citizens Advice confirms that the law does not define what counts as reasonable. The official explanatory notes give an example: a plumber who fixes an urgent leak in ten minutes with a £50 part is unlikely to be entitled to £1,000. Two rules narrow the room further for consumer work. The Consumer Contracts Regulations 2013 require you to give the total price including taxes before the contract is made, or, where the price cannot reasonably be calculated in advance, the manner in which it will be calculated (Schedules 1 and 2). Section 50(3) and (4) of the Consumer Rights Act then make that information a term of the contract, and a change to it has no effect unless the consumer expressly agrees. The US has no single federal tolerance either, but some trades have their own rules.
Car repairs in California: the repair dealer must give the customer a written estimated price for labour and parts, and no charge may be made above that estimate without the customer's oral or written consent (California Business and Professions Code section 9884.9)
Car repairs elsewhere in the US: the Federal Trade Commission advises consumers to get a written estimate stating that the shop will ask for approval before exceeding a specified amount of time or money, and notes that state law may require this
Interstate household moves: federal rules let a mover give a binding estimate, above which it may not collect except in limited cases, or a non-binding estimate that must be reasonably accurate. Under a non-binding estimate the mover must hand over the goods at delivery once the customer pays up to 110 percent of it, plus certain added charges (49 CFR 375.403, 375.405 and 375.407)
Everything else: set your own tolerance in writing, such as within 10 percent, and promise to ask before going past it. That number is your commitment, not a legal default
When should you send an estimate, and when a quote?
Send an estimate when the client needs a number to decide whether to go further and you cannot yet see the whole job. Send a quote when the scope is clear enough that you are willing to be held to the price.
Estimate: a first enquiry, a budget check before a site visit, repair work where the fault is hidden, and projects where the client has not chosen materials or features yet
Quote: after a site visit or a detailed brief, repeat work you have priced before, fixed deliverables such as a website with a set number of pages, and any time the client compares suppliers on price
Estimate first, quote second: many jobs start with an estimate and end with a quote. Send the estimate early, then replace it with a quote under a new number once you have measured, inspected or agreed the specification
Mixed jobs: when part of the work is fixed and part is unknown, quote the fixed part and estimate the rest, clearly labelled, in the same document
How do you word an estimate so it is not read as a quote?
Label it, give a range or a figure with a tolerance, name your assumptions and say what happens if they turn out wrong. Put these qualifications on the same page as the figure, because section 50(2) of the Consumer Rights Act gives weight to qualifications made on the same occasion as the price. Here is example wording for a fictional decorator, Harbour Decorating.
Heading: Estimate E-2026-031. This is an estimate, not a fixed quote
Scope: repaint the living room and hallway, walls and ceilings, two coats, furniture cleared by the client
Estimated price: £1,850 to £2,150 including VAT (US version: $2,300 to $2,700, plus sales tax where it applies)
Based on: walls in sound condition, no more than two hours of filling, colours from our standard range
The price may change if: plaster needs repair, colours change after work has started, or access takes longer than agreed
Our promise: we will tell you in writing and ask for your approval before the price goes above £2,150
Next step: after a site visit we will send a fixed quote, valid for 30 days
How do you word a quote so it is clear and firm?
A quote should leave nothing to interpret. State the scope, the exclusions, the price, the validity date and the payment terms, and ask for written acceptance. If you send quotes as a link, Proposal Expert shows you when the client opens it and records the electronic signature with a trusted timestamp and a sealed audit trail, which settles which version was accepted and when. Here is the same decorator after the site visit.
Heading: Quotation Q-2026-044, fixed price
Scope: as described in estimate E-2026-031, plus repair of two cracks in the hallway ceiling
Not included: woodwork, wallpaper removal and moving heavy furniture
Price: £2,040 including VAT at 20 percent (US version: $2,550, with sales tax shown separately where it applies)
Valid until: 30 April 2026
Payment: 25 percent on acceptance, the balance within 14 days of completion
Changes: any extra work will be agreed in writing, with its price, before we start it
Acceptance: sign below or electronically to accept this quotation and these terms
Frequently asked questions
Is a quote the final price?
For the work described in it, yes. Once the client accepts, you cannot add charges for the same scope, and extra work needs the client's agreement first. For UK consumers the quoted price should include VAT, because the Consumer Contracts Regulations 2013 require the total price inclusive of taxes. In the US, the SBA notes that sales tax can vary significantly from place to place, so say whether tax is included or added.
What is a fixed estimate?
A fixed estimate is a quote under another name. Citizens Advice notes that a quote is sometimes called a quotation or a fixed estimate. If you do not want to be held to a figure, do not use the word fixed. Write estimate, give a range and list what could change it.
Can a contractor charge more than the quote?
Only in limited cases. In the UK, Citizens Advice says the trader can charge more only if the customer agreed to pay for extra work the trader said was needed, or if the quoted price was an obvious mistake. Higher material costs after the quote are not enough. To protect yourself, give quotes a short validity date and agree every change in writing before you do the work.
Is a binding estimate the same as a quote?
In most trades the phrase has no fixed meaning, and a figure you promise not to exceed works like a quote. In US interstate household moves it is a defined term. There, a binding estimate caps what the mover may collect, with limited exceptions, while a non-binding estimate must be reasonably accurate and the customer can take delivery by paying up to 110 percent of it (49 CFR 375.403, 375.405 and 375.407).
Should an estimate be in writing?
Yes. A written estimate shows what you assumed and what you promised, which is exactly what matters if the bill is disputed. For UK consumer contracts made away from your business premises, regulation 10 of the Consumer Contracts Regulations 2013 requires the pre-contract information, including the price or how it is calculated, on paper or, if the consumer agrees, on another durable medium. Keep a copy of exactly what you sent.