Quote vs estimate: the difference that decides who pays when the job grows
Customers use the words interchangeably. The law doesn’t. A quote is an offer to do defined work for a fixed price — accept it and there’s a contract at that price. An estimate is an informed prediction that the final bill may lawfully differ from. Most pricing disputes in the trades are really quote-vs-estimate confusion, which makes this the cheapest legal knowledge a tradesperson can own.
What a quote is
A quote is a fixed price for a defined scope of work. Once the customer accepts it, it becomes a binding agreement: you must do that work for that price, even if it takes longer or materials cost more than you allowed. That’s not a flaw — certainty is what customers are buying, and it’s why quotes win work.
The protection is in the definition: a quote should state what’s included, what’s excluded, how long the price is valid (“valid for 30 days” protects you from materials inflation), and how changes will be handled.
What an estimate is
An estimate is your informed judgement of the likely cost — a guide, not a commitment. The final invoice can differ, but not without limits: a final bill wildly beyond the estimate with no warning is where customers dig in and, for consumer work, where reasonableness rules bite. If the job starts running past the estimate, say so before continuing, not on the invoice.
When to use which
- Quote: defined, visible work — a boiler swap, a rewire with a proper survey, a bathroom to a spec. Customers prefer it and it wins jobs
- Estimate: genuinely unknowable scope — fault-finding, opening up floors and walls, damp and rot where the extent is hidden
- Hybrid (often best): a fixed quote for the known work plus stated provisional sums or day rates for the unknowns — certainty where possible, honesty where not
Variations: where fixed prices go to die
Almost every dispute follows the same script: the scope changed mid-job, the price change was verbal or implied, and the final invoice was a surprise. The fix is procedural, not legal: when anything changes, price the variation in writing — a two-line message is enough — and get a yes before doing it. “While you’re here” is a new quote, not a favour.
Paper trails without paperwork
The habit that prevents disputes is writing things down at the moment they happen — which only works if it takes seconds. TradeHub OS quotes carry scope, exclusions and expiry; customers accept and sign online, timestamped; and variations are sent, priced and accepted from your phone mid-job. The whole trail lives on the job when memories later differ.
This guide is general information for UK trades and landlords, not legal advice. Always refer to the current regulations and official guidance from the HSE, Gas Safe Register or your competent-person scheme.
