Published 4 November 2026

Effective November 2026

People use our calculators to plan one of the biggest purchases they’ll make, so accuracy comes first. This page explains how we research, check and update what we publish.

For duty rates, thresholds and concessions we use primary sources only:

• State and territory revenue office websites, rate tables and published examples
• The revenue offices’ own calculators, which we use to check our results
• Legislation and legal instruments, such as the ACT’s annual duty determinations

Third-party calculators, news articles and forums can point us to a change, but we never take a figure from them without confirming it at the source.

1. Research. We record each rule with its source URL, the date it starts and, where relevant, the date it ends.
2. Implementation. Rates live in code, separate from the content system, so editing a page can’t change a statutory calculation by accident.
3. Testing. Every rule has automated tests, including bracket boundaries, rounding, concessions and dates before and after a change. Where a revenue office publishes an example or a calculator, our result must match it.
4. Review and approval. A change is reviewed before it is published, and every version is kept in the project history so it can be rolled back.
5. Honest limits. If a contract date falls outside the dates we’ve verified, or a concession depends on information we don’t ask for, the calculator says so instead of estimating.

Guides are written for the reader’s actual question, checked against the same primary sources, and dated. Each guide lists its sources and its last review date. We don’t invent statistics, credentials or quotes, and we don’t list qualifications nobody holds.

We are not affiliated with any government agency, lender or broker. Advertising never decides what we say about a scheme, a cost or a product.

AI tools may help with research, organisation and proofreading. They are never used to publish automatically, and every figure is checked by a person against its official source before it goes live. See our AI content policy.

Duty rules change with state budgets and at the start of each financial year. We review every jurisdiction’s rules at least each July, and whenever a revenue office announces a change. Each calculator result shows when its rules were last verified.

If a figure looks wrong, please tell us. Include the state, price, options and contract date you used, and a link to the official source if you have one. Email editorial@ozstampdutycalc.com.au. We treat errors in figures as our top priority.