Transfer duty is the tax an Australian buyer pays to the state or territory when a property changes hands. Most people still say stamp duty, the older name. Revenue NSW charges it to the buyer, never the seller, and wants it within three months of signing the contract, or by settlement if that comes first, because settlement cannot happen until it is paid.
Each state sets its own scale, so the same price can carry quite different duty in Sydney, Melbourne and Brisbane. The New South Wales scale is published as a base amount plus a rate per $100 above each threshold, and Revenue NSW adjusts the thresholds every year in line with the CPI. For contracts from 1 July 2026 to 30 June 2027 the band from $387,000 to $1,290,000 pays $11,602 plus $4.50 per $100 above $387,000. A $900,000 home therefore pays $11,602 plus $23,085, which is $34,687. Above $1,290,000 the rate is $5.50 per $100, and a premium rate of $7.00 per $100 applies to residential property above $3,870,000.
First home buyers often pay far less. Under the NSW First Home Buyers Assistance scheme, an existing home worth up to $800,000 is exempt altogether and one between $800,000 and $1 million pays a concessional rate. Other states run their own schemes with different limits.
The Australian mortgage calculator applies a New South Wales scale by default and adds the duty to your cash to complete. It does not apply first home buyer concessions or another state's scale, so check your own state revenue office before you rely on the figure.