Contractors use estimate, quote and proposal interchangeably, and clients hear them differently. The word at the top of the page matters less than what the document says: whether the price is fixed, what it includes, how long it holds and what happens when the job changes. Here is one fictional bathroom job written up all three ways.
The short answer
- An estimate is your best calculation of what the work will cost the client, and it says so. It can move as you learn more.
- A quote is a price for a defined scope, held for a stated period. It changes only through a change order.
- A proposal is the package a client approves: the price, the scope of work, exclusions, allowances, options, schedule and terms.
The same job, three documents
As an estimate: eight lines costing $9,407.00, priced at $11,100.26 before tax and $11,655.27 with GST, marked as an estimate because nobody has opened the walls yet.
As a quote: the same total, with the scope written precisely enough to check (52 sq ft of tile, two coats of paint), a $2,800 fixture allowance, exclusions for anything behind the walls, and a 30-day validity date. If the client wants more, it is a change order.
As a proposal: the quote plus the scope of work, who supplies selections and the permit, the milestones and how each is accepted, and a place to approve. In this example the client approves it, and the approved price becomes the contract.
Revisions before and after approval
Before the client approves, revise the document and send a new version; keep the old ones so nobody argues later about what was offered. After approval, the contract does not change by editing the estimate. It changes by change order, priced and approved before the work.
In this job the client added a niche and a glass door after approval. That went through a $1,450.00 change order, and the revised contract became $12,550.26. Our worked example follows the same job from estimate to the final invoice.
What the law says about going over an estimate
Rules differ by province and state, and by whether the client is a consumer or a business, so there is no single answer to whether an estimate or a quote binds you. One clear example: in Ontario, section 10 of the Consumer Protection Act, 2002 says that if a consumer agreement includes an estimate, the supplier must not charge more than 10 per cent above it. If they do, the consumer can require the work at the estimated price. The same section lets both sides agree to amend the estimate when the consumer asks for additional or different work.
That reading is from the consolidated Act on Ontario's e-Laws site, current to October 30, 2026. The Act is due to be replaced by the Consumer Protection Act, 2023 on a date still to be proclaimed, so check the current rule before relying on it. Elsewhere in Canada and in the US, the rule comes from that province's or state's consumer law and from the wording of your contract. This is general information, not legal advice.
How BuildersBridge handles the three
In BuildersBridge an estimate and a quote are the same priced document: you send it as a PDF or as a proposal the client approves in their portal, and every version is kept. Bridge AI can draft the lines from a description, but a draft is never sent on its own and never a binding quote; you review it and decide what goes out. Once approved, it sets the contract value, and later changes go through change orders.