Estimate vs quote vs bid: what's the difference, and which one to send
Estimate, quote, bid — most people use the three words as if they're the same thing, and most of the time it doesn't matter. Until it does: the day a customer holds you to a "quote" you meant as a ballpark, or you lose a job because you sent a casual estimate where the client wanted a firm price. The words carry different promises, and knowing which one you're handing over protects both the price and the relationship.
Here's the short version, the real difference between the three, and how to decide which one to send — without needing a lawyer to read your paperwork.
The one-line version
If you remember nothing else: an estimate is a guess, a quote is a promise, and a bid is a competition. An estimate is your best educated approximation of what a job will cost. A quote is a firm price you're committing to. A bid is a formal price you submit to win work against other contractors. Same ballpark, very different weight — and the difference is mostly about how binding the number is.
Estimate: a ballpark, not a promise
An estimate is your educated approximation of the cost, based on what you know so far. It can be verbal or written, and in most cases it isn't legally binding — it's meant to give the customer a realistic range to plan around before the scope is fully nailed down. Estimates are right for early conversations, for jobs where the scope could still shift, or for work where you genuinely can't know the final number until you open a wall.
The catch is that a sloppy estimate gets remembered as a quote. If you say "probably around eight grand" and the final bill is eleven, the customer feels misled even though you were guessing in good faith. So if you give an estimate, label it one, and say plainly what could move the number — material prices, hidden conditions, choices not yet made.
Quote: a firm price you can sign
A quote is a detailed, written price for a defined scope — and once the customer accepts it, it can function as a binding agreement. That's the whole point: the customer knows exactly what they'll pay, and you've committed to deliver the named scope for that number. Quotes usually carry an expiry ("valid for 30 days") because your material and labour costs move, and they should spell out exactly what's included so there's no daylight between what you priced and what they expect.
This is the document most residential contractors should be sending most of the time. In Stairkey you build the scope as plain line items or straight from measured takeoff, send a clean estimate, and collect the customer's approval on the record — so the "yes" is documented, not a half-remembered phone call. The piece that protects a quote afterward is the change order: when the customer asks for more, it's tracked against the original scope instead of quietly eating your margin. For the anatomy of a quote that wins, see how to write a detailed contractor quote.
Bid: a formal offer in a competition
A bid is a formal price you submit in response to a request — from a general contractor, a property manager, or a government agency — usually competing against other contractors for the same job. Bids are the norm on larger commercial, municipal, and government work, where the process is structured: there's a spec to price against, a submission deadline, and an award. A bid is an offer to do defined work for a stated price and timeline, and if you win, it generally becomes the basis of the contract.
For most residential and small-commercial contractors, day-to-day work is quotes, not bids — but when you do chase bid work, the discipline is the same one good quoting builds: price from real quantities, document the scope precisely, and know your margin cold before you commit. That's the case for running estimating on one system instead of a pile of spreadsheets — see construction estimating software.
Which one to send
Send an estimate when the scope is still loose and you want to give the customer a planning number without committing — just label it clearly and name what could change. Send a quote when the scope is defined and the customer wants a firm price they can say yes to, which covers most residential jobs. Submit a bid when you're competing for a job through a formal request with a spec and a deadline.
Whichever you send, the move that protects you is the same: write it down, define the scope, and keep the approval on the record. Want a head start? Grab the free estimate template to lay out a clean scope, then see how a walkthrough becomes a signed estimate in the walkthrough-to-signed-estimate guide.