How long should an estimate be valid?

Thirty days is what most estimates say, and for most of them nobody decided it — it is the number that was already in the template. Sometimes it is right. On a job priced on today's parts, fuel and a slot in next week's calendar, it is a month of exposure you are giving away for free.

Ask what moves your cost

The period is not about how long you would like the client to take. It is about how long your own numbers stay true. Work backwards from the thing most likely to move: the price of materials, a supplier quote you are relying on, fuel, a subcontractor's availability, or nothing much at all if the job is mostly your own hours.

The trades at the short end are the ones whose whole job is urgency — a vehicle off the road, a flooded floor, a load that has to move. There the estimate is not being considered for weeks anyway, so a long validity buys nobody anything and quietly exposes you to the next price list.

What an estimate with no expiry actually says

It says the price stands until you tell the client otherwise, and telling them otherwise is a conversation nobody enjoys. Every trade has the story: an estimate accepted six months on, at a price that has since stopped making sense, and a client who is entirely reasonable to be annoyed about it. The expiry date is what makes that conversation unnecessary rather than awkward.

  • Put the date on the document, not in a covering email nobody keeps.
  • Say it as a date rather than a duration — "valid until" needs no arithmetic from the reader.
  • If the estimate lapses and the client comes back, re-issue it rather than honouring the old one silently.
  • Re-issuing is not a penalty. It is the moment to reflect what has actually changed.

A quote is the same question with less room

On a fixed price the expiry is doing more work, because there is no wording about prices moving to fall back on. If you are quoting rather than estimating, pick the shorter period of the two you were considering.

Make an estimate

Common questions

What if a client accepts an expired estimate?
Nothing obliges you to honour it, and how you answer is a commercial decision rather than a rule. Re-issue at today's numbers and say what changed — most clients accept that far better than a price rise discovered on the invoice.
Should the expiry be longer for bigger jobs?
Usually yes, because bigger jobs take longer to decide — but a long decision is also a long window for costs to move, so pair it with an assumption that names the supplier prices the estimate rests on.
Does the expiry date affect when payment is due?
No. When an offer stops standing and when the money is owed are unrelated. Payment terms start from the invoice, and a converted invoice gets its own.

Figures on this page last reviewed 2026-08.

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