Estimating Jobs
Estimate vs Quote: Why the Word You Use Matters
Short answer
An estimate is a good-faith ballpark and can legally change as scope clarifies. A quote is a binding offer at a fixed price. Use 'estimate' for unknown-scope work where final cost depends on what you find; use 'quote' for defined-scope work where you can commit to a number.
Most service-business owners use 'estimate' and 'quote' interchangeably. Customers do too. But in contract law and in customer-perception terms, they mean very different things — and using the wrong word at the wrong time is the easiest way to either give away margin or end up in a small-claims hearing.
The legal difference
An estimate is an opinion of probable cost. It is not a binding price. A reasonable variance (often 10–25%) is expected and accepted. The contractor is not legally required to honor the original number if scope expands or costs change.
A quote is a fixed-price offer. Once the customer accepts, you are contractually bound to deliver the work for that amount. Cost overruns come out of your pocket, not the customer's.
States vary on the specifics. California, for example, requires written contracts above $500 and treats vague price terms as ambiguous-to-the-contractor. Check your state's contractor licensing rules.
When to use 'estimate'
- Renovation work where you can't see behind the walls
- Drainage, electrical, or HVAC diagnostic work
- Time-and-materials jobs
- Any project where scope is likely to expand once started
When to use 'quote'
- Install a defined product (water heater, dishwasher, light fixture)
- Standard maintenance contracts
- Replacement work where scope is fully visible upfront
- Anything you are happy to commit to a fixed price on
How to write each document
An estimate document must state 'ESTIMATE — subject to change based on actual scope.' Include a variance allowance (e.g., '±15% expected variance'). Define what triggers a change order.
A quote document must state 'QUOTE — fixed price, valid for 30 days.' Include the exact scope and exclusions. Make clear that any work outside the listed scope requires a written change order at additional cost.
Customers prefer quotes because they remove uncertainty. Use quotes whenever you can; reserve estimates for genuinely unknown-scope work.
Frequently asked questions
Can I turn an estimate into a quote?
Yes — once scope is locked. Do an inspection or partial demo, then issue a firm quote for the remaining work. Customers appreciate the upgrade from uncertainty to certainty.
What if the customer agreed to an estimate and now disputes the higher final bill?
Document the scope changes and material price changes in writing as they happen. If you didn't, the customer has a good argument that you should honor the original number.
Is a verbal quote binding?
In some states, yes — for small amounts. In most states, written quotes are required above a threshold. Never give a binding verbal quote on anything material; send a written follow-up the same day.
Turn pricing into invoices.
Glo Invoice creates branded estimates and invoices from your pricing in seconds — free for 14 days.
Sources & further reading
Primary sources we consulted when writing and reviewing this guide.