Estimate
An estimate is your best professional judgement of what the work will cost, based on what you can see and reasonably assume. It carries conditions: hidden damage, access problems, material availability, or code requirements discovered during work can move the number.
Estimates are appropriate for repair work, anything behind a wall or under a surface, and any job where the scope cannot be fully verified before starting.
Quote
A quote is a fixed price for a defined scope. Once the customer accepts it, the price holds unless the scope changes through a written change order. Quotes are appropriate when the work is fully visible and measurable — a replacement, an installation, a defined maintenance package.
The risk transfers to you. That is why quoted work needs a tighter scope statement and clear exclusions than estimated work does.
Proposal
A proposal is a document, not a price type. It explains the problem, the recommended approach, the options, the timeline, and the terms, with a quote or an estimate inside it. It exists for jobs where the buyer is comparing approaches rather than only comparing numbers — larger projects, commercial work, or anything with a design component.
How to choose
- Can you see and measure everything? Quote it.
- Are there unknowns behind surfaces? Estimate it, and name the unknowns.
- Is the customer choosing between approaches? Write a proposal.
- Is the customer choosing between contractors on price alone? Quote it and make the exclusions explicit.
The part people skip
Whichever document you send, the enforceable content is the scope. A fixed price against a vague scope is worse than an estimate against a precise one, because the argument moves from 'what will it cost' to 'what did you agree to do'. Precision in the scope is what protects the price.