How we source and verify these rates
Stamp duty is a number people make property and vehicle decisions on. Here is exactly how we get it, checked, and kept current.
Primary sources only
Every rate on this site comes from the relevant state or territory revenue office's own published schedule, or — where a revenue office's own page could not be reached — the Act that governs it. We never take, infer or average a rate from another calculator, a bank's page, or a news article. Each result on the site links to the specific page the figure came from, and states the date we last checked it.
If we can't verify it, we don't show it
Where a figure could not be confirmed against a primary source, we omit it rather than estimate. A missing state is visible; a wrong one is not. South Australia's rates were recovered this way and shipped only after a human confirmed them against RevenueSA's own pages — a step we record rather than hide.
Every published worked example, reproduced
Where a revenue office publishes a worked example — a specific price and the duty it produces — our test suite reproduces it exactly before anything ships. Where an office publishes no worked example, we check that its own bracket base amounts are internally consistent: the duty stated at the top of one bracket has to equal the duty calculated at the bottom of the next. Both checks run automatically, every time a rate changes.
What we do not model
A handful of narrow concessions are noted with a source link rather than calculated — Victoria's green passenger vehicle concession is one — where the eligibility test itself could not be independently verified. We would rather tell you a concession might apply and point you to the source than silently get it wrong.
Kept current
Rates change at state budgets, almost always effective 1 July. We review the full set at that point, and record the date next to every figure so a stale rate is visible in the product, not just in a changelog.