An estimate gives a rough price guide before all details are known; a quote offers a price for a defined scope. An accepted quote can form a binding contract, so record the scope, assumptions, exclusions and how changes will be agreed. The label alone does not settle the effect of an agreement.[1][2]
Estimate versus quote
Business Queensland says an estimate is a rough guide given without having all the specifications. It usually carries a disclaimer that the price is subject to change. A quote means you have the information needed for a well-planned, correctly calculated price, and if the customer proceeds it forms part of a legally binding contract.
Business Queensland also says an accepted quote becomes legally binding, so confirm acceptance in writing before you start work or order materials. This is Queensland guidance, and the rules on trade contracts can differ by state or territory.
Sources[1]
Side-by-side
The wording in the last column is our recommendation.
| Item | Estimate | Quote |
|---|---|---|
| Use when | Owner wants an indication before inspection | Scope is defined and you can price it |
| Price | A rough figure or range with stated assumptions | A line-item price with the GST component shown |
| Status | Business Queensland says not legally binding | Business Queensland says it forms part of a contract if the customer proceeds |
| Wording | State what is unknown and what would change the price | State inclusions, exclusions, expiry and how to accept |
Sources[1]
Fictional example
A homeowner asks about replacing a hot water unit before anyone has seen the site. The plumber replies with an estimate of $1,800 to $2,400, GST included, based on a like-for-like unit and clear access, and says the price may change after inspection. After inspecting, the plumber sends a quote with a fixed price for a named unit, installation and removal of the old one, plus exclusions such as any pipework repairs. These figures are illustrative only.
Quote checklist
Drawn from Business Queensland's quote content and Business.gov.au's contract points. It is a practical checklist, not a legal form.
[ ] Business name, ABN, contact details [ ] Quote number, date and expiry date [ ] Customer name and site address [ ] Scope of work described in plain terms, with start and finish timing [ ] Line-item costs, total and GST component [ ] Inclusions and exclusions (for example, making good or extra pipework) [ ] Assumptions the price depends on (access, existing condition) [ ] Payment terms and accepted payment methods [ ] How variations are priced and agreed in writing [ ] Customer acceptance line with name and date
If details change
Business Queensland says to issue a revised quote if the job's specifications change, and to add an expiry date because material costs can rise quickly. Business.gov.au says contract changes are best made in writing and signed or confirmed by both parties.
Common questions
- What is the difference between an estimate and a quote?
- Business Queensland says an estimate is a rough guide to cost without all the specifications and is not legally binding. A quote is a detailed price that forms part of a legally binding contract if the customer proceeds.[1]
- How legally binding is a quote?
- Business Queensland says that once a customer accepts a quote it becomes a legally binding contract, so get acceptance in writing and make sure the scope and exclusions are accurate before you send it. For a specific dispute, ask a lawyer.[1]
Official sources
Checked 16 October 2026. Rules can change; use these sources to check the requirements for your job.
Related guides
- Free quote template for Australian tradies
- What should a building variation form include?
- When should a trade business use cost-plus or fixed-price pricing?
Job workflows for plumbers.
Put it to work on the next job
Leadhand lets you build a quote from your pricebook, show the scope and GST-inclusive price, and have the customer accept it online.
See Leadhand quoting