An estimate is an approximation of what a job will cost — the number can move as the job reveals itself. A quote is a firm price the customer can hold you to. A bid is a firm price competing against other contractors on a defined scope, and a proposal is the sales document built around one. We build Voice Estimate around the first kind, because that's the document most trade jobs actually run on.
The words get swapped every day on job sites, and mostly nothing happens. Where it matters is the paper: what the document says about the price decides what you can charge later — not the word at the top.
What's the difference between an estimate, a quote, a bid, and a proposal?
An estimate approximates the cost and is expected to change. A quote fixes the price once the customer accepts it. A bid is a fixed price submitted in competition on a scope someone else defined. A proposal is a quote or bid plus the case for hiring you. The real difference is commitment — how firm the number is, and who defined the scope.
| Document | What it says | How firm the price is | When to use it |
|---|---|---|---|
| Estimate | "This is what the job should cost, based on what I can see." | Expected to move as the job reveals itself — and the paper should say so | Most residential trade work: repaints, re-roofs, fences, anything with tear-out or unknowns |
| Quote | "This is the price." | Firm once accepted; changing it needs the customer's sign-off | Well-defined scope you've done a hundred times, no surprises waiting behind a wall |
| Bid | "This is my price for your defined scope." | Firm — you're being compared line by line against other contractors | Commercial, GC, and public work, where the client hands you the scope and the format |
| Proposal | "Here's the price — and here's why us." | As firm as the quote or bid inside it | Bigger jobs where you're selling the approach and the crew, not just a number |
Does the word at the top matter?
Less than what's written under it. In a dispute, what gets read is the substance of the document — the price language, the scope, the signatures — not the title. A detailed "estimate" with a firm price and a customer signature can be enforced like a contract, as Levelset's breakdown of estimates, proposals, and contracts lays out. An airy one-line "quote" with no scope behind it protects nobody.
That cuts both ways. Write "quote" at the top out of habit, and when the tear-out doubles, the title you chose is evidence the price was firm. Hand over a signed "estimate" that reads like a fixed-price offer, and don't count on the title to make it flexible. The fix costs one sentence in the terms: "Final cost may adjust by written change order" on an estimate, or "Price firm for 30 days from acceptance" on a quote.
Everything else on the document is the same in all four cases — scope in plain words, line items with quantities, exclusions, terms. How to write a job estimate covers that structure section by section.
Can a contractor charge more than the estimate?
Sometimes. An estimate is an approximation, but there is no universal percentage a contractor is automatically allowed to add. The written agreement and state law control. Angi says a 5–20% overrun can be reasonable on a home-improvement estimate, but that is consumer guidance, not a nationwide legal tolerance. Nolo's current guidance focuses on what the parties agreed to in writing, state home-improvement law, advance notice, and whether the customer approved the added work (both checked August 2026).
But the percentage isn't what protects you — disclosure is. Subject to the agreement and your state's rules, written approval before extra work begins is what gives an added charge its footing; work the customer first hears about on the final invoice is a nonpayment fight at almost any size. Moving a price without the fight takes three steps:
- Name the unknown before it's found. An assumptions line on the estimate: "Assumes decking is sound; hidden damage priced after tear-off." Now the surprise is expected, not sprung.
- Price the surprise before the work, in writing. A change order with its own scope and its own number — two sentences and a price is enough.
- Get the yes before the saw. A signature or a clear written OK, then do the work. Approval after the fact isn't approval; it's a negotiation you started from behind.
Do that, and "how much over can you go" stops being a percentage debate — every dollar above the original number has its own signed paper.
Which one should you send?
- Residential work with any unknown in it: send an estimate, written with quote-grade specificity — visible quantities, exclusions, and the change-order sentence. You get a document that wins trust and a price that can still breathe.
- A tight, repeatable scope you could price in your sleep: send a quote, and say how long the price holds. Customers pay for certainty; give it where you actually have it.
- Commercial, GC, or public work: it's a bid, whether you'd call it that or not — the client defines the scope, the format, and the deadline. Your job is matching their line items, not naming the document.
- A bigger job where you're selling the approach: wrap your estimate or quote in a proposal — the plan, the crew, the timeline. The price section inside still follows the rules above.
How little separates the first two on paper:
SAME $900 DECK JOB · TWO DOCUMENTS
ONE SENTENCE APART
Estimate: "Estimated total $900. Boards found soft after washing are priced by written change order before staining begins." Quote: "Total $900, firm for 30 days from acceptance." Same scope, same number — the terms sentence is the entire difference.
A voice script that keeps an estimate an estimate
The flexibility has to be spoken into the document, not assumed. Here's a bathroom tile walkthrough dictated so the paper comes out an estimate — firm where the scope is known, open where it isn't:
"Estimate for the hall bath at 27 Grove Street. Tear out the shower surround and re-tile, about 90 square feet of wall tile, customer supplies the tile. Demo and haul-away is 300. Tile setting is 14 dollars a square foot. Thinset, backer board, and grout, 260. Anything behind the backer board — rot, mold, framing — is a separate change order after demo. Fifty percent deposit on acceptance, and the price is good for 30 days."
Where each phrase lands: "90 square feet" and "14 dollars a square foot" are extracted as the literal numbers you spoke, and the server multiplies them — the AI never does arithmetic. The change-order sentence becomes the scope language that keeps the document an estimate. "Fifty percent deposit on acceptance" lands in the acceptance terms as a condition of the job — not money received. And "good for 30 days" sets the validity date because you actually said it. You review the draft, then send it before the customer's had time to call anyone else.
Common mistakes with estimates, quotes, and bids
- Writing "quote" out of habit. If the price can move, the title just handed the customer an argument that it can't.
- A bare total with no firmness language either way. The customer reads it as firm. You meant it as movable. Both of you are sure you're right.
- Treating a signed, detailed estimate as non-binding. Substance controls over title — a firm price, a tight scope, and a signature behave like a contract whatever the top of the page says.
- Leaving the change-order mechanism unwritten. The 10–20% tolerance debate only happens on jobs where nobody wrote down how extra work gets priced.
- Quoting a job with tear-out in it. A firm price on an unknown means you own the surprise. If you can't see it, estimate it — and name it in the assumptions.
What to review before you send
- The title matches the firmness of the price — and the terms say it explicitly, in one sentence
- If it's an estimate: the change-order mechanism is written, not implied
- If it's a quote: the scope is tight enough to defend, and the price window is stated
- Deposit is worded as a condition of acceptance, with balance timing
- Validity date is on the document
- Quantities and units are visible behind the number, so the price reads as math, not a hunch
FAQ
Is a quote legally binding once the customer accepts it?
It can be. An accepted quote may form an enforceable contract when its wording identifies a firm price and defined scope, but the result depends on the document, how it was accepted, and state law. Treat a quote as a commitment: ordinary overruns do not automatically let you raise the price after acceptance.
Can a contractor charge more than the estimate?
Sometimes. An estimate is an approximation, but there is no universal percentage a contractor may add: the written agreement and state law control. What makes extra cost defensible is advance disclosure and a written change order the customer approved before the extra work was done, not a larger invoice at the end.
What is the difference between a bid and an estimate?
A bid is a price submitted in competition against other contractors on a scope the client defined, and it is usually firm. An estimate is your own approximation for one customer, built from your walkthrough, and it is expected to move if the job reveals more work. Bids compete; estimates open a conversation.
Is a proposal the same as a contract?
No. A proposal is a sales document — the price plus the case for hiring you. But if it carries a firm price, a defined scope, and both signatures, it can function as a contract regardless of the title. If you don’t want a proposal to bind you, say in it that work is subject to a separate signed agreement.
Should I write "estimate" or "quote" at the top of the document?
Match the word to how firm the price is, then say it explicitly in the terms: "final cost may adjust by written change order" on an estimate, or "price firm for 30 days from acceptance" on a quote. The wording inside the document controls over the title — a mismatch between the two only buys you an argument.
Do contractors charge for estimates?
Most residential estimates are free — the walkthrough is part of winning the job. Charging is fair when the estimate itself is real work: design time, engineering, or a detailed takeoff the customer could shop around. If you charge, name the fee up front, and consider crediting it against the job if you’re hired.