Stamp duty on a property (at our value estimate)
/v1/properties/{gnaf_id}/calculators/stamp-duty11¢ per callStamp duty on buying this property at our value estimate — the same
calculation as /calculators/stamp-duty, with the state taken from the
property and the price set to our automated value estimate for it
(price_source: value_estimate).
Use it to show "stamp duty on this home" on a listing or a property page
without knowing the price. Priced as the calculator plus the value estimate.
When you know the agreed price, use /calculators/stamp-duty instead — it is
cheaper and exact. No value estimate for the property → available: false.
Authorization
Request
The only values you send. Fields under Responses below are what comes back — you never pass those.
Path parameters
gnaf_idstringrequiredQuery parameters
buyer_typestringoptional`first_home` (first home buyer who will live in it), `owner_occupier` (will live in it, not a first home), `investor`, or `foreign` (a foreign person under state law — surcharge duty applies, no home concessions).
property_typestringoptional`established` (an existing home), `new` (a new home or off-the-plan, never lived in), or `vacant_land` (land to build a home on).
contract_datestring · dateoptionalContract date (YYYY-MM-DD); picks the rates in force on that day. Default: today in Sydney.
off_the_planbooleanoptionalBought off the plan. Changes the answer only where a state has an off-the-plan concession.
regionalbooleanoptionalOutside the capital city (WA: outside Perth and Peel; also the WA grant's northern cap). Ignored where a state draws no such line.
household_incomenumber0–∞optionalGross household income for the past year — used by income-tested schemes (ACT). Omit and we assume you meet the income test.
dependantsinteger0–20optionalDependent children — raises an income-tested scheme's limit (ACT).
pensionerbooleanoptionalHolds an eligible pension or concession card. Changes the answer only where a state has a pensioner concession.
Responses
Successful Response
statestringalways returnedNSW, VIC, QLD, WA, SA, TAS, ACT or NT.
pricenumberalways returnedDutiable value used: the price you passed, or our value estimate on the property route.
price_sourcestringalways returned`input` (you passed it) or `value_estimate` (our estimate for the property).
gnaf_idstringmay be nullThe property, on the property route; null otherwise.
buyer_typestringalways returnedfirst_home, owner_occupier, investor or foreign.
property_typestringalways returnedestablished, new or vacant_land.
foreignbooleanalways returnedWhether the foreign purchaser surcharge was applied.
contract_datestring · datealways returnedDate the rates were picked for.
general_dutynumberalways returnedDuty at the general rate, before any concession.
concessionnumberalways returnedAmount taken off by concessions or exemptions (0 when none apply).
concession_namestringmay be nullThe concession or exemption that applied, if any.
foreign_surchargenumberalways returnedForeign purchaser surcharge duty (0 unless foreign).
total_dutynumberalways returnedWhat you pay: general_duty − concession + foreign_surcharge.
effective_rate_pctnumbermay be nulltotal_duty as a % of price; null when price is 0.
breakdownarray of CalcLinealways returnedEvery step, in order; amounts sum to total_duty.
ratesobjectalways returnedWhich rates table the answer used. Rates change each financial year (or land tax year); the version in force on your date is picked for you.
caveatsarray of stringalways returnedWhat this calculation assumes or leaves out.
About this data
What this is
Stamp duty on buying one property at our automated value estimate for it. The state comes from the property, so you only pass the buyer's situation. The working is the same as /v1/calculators/stamp-duty.
What people use it for
- Listing and property pages: show "stamp duty on this home" when there is no advertised price.
- Buyers: budget for a home before the price is known.
- Brokers: estimate funds to complete for a client's target property.
Tips
price_source: value_estimate marks a duty worked out from our estimate, not an agreed price. When you know the price, use /v1/calculators/stamp-duty for an exact figure. Properties we have no value estimate for return available: false; our estimate itself is at /v1/properties/{gnaf_id}/valuation/avm.
/v1/properties/{gnaf_id}/calculators/stamp-dutycurl --request GET \
--url 'https://api.microburbs.com.au/v1/properties/GANSW704074813/calculators/stamp-duty' \
--header 'Authorization: Bearer test'{
"data": {
"breakdown": [
{
"amount": 32437,
"detail": "$850,000 on the general rate: $11,602 + 4.5% of the value over $387,000 (per $100 or part).",
"item": "Transfer duty"
},
{
"amount": -22640.25,
"detail": "Concession for a first home (new or established) valued between $800,000 and $1,000,000: the duty on $800,000 ($30,187) shrinks in a straight line to nothing at $1,000,000, so $22,640.25 comes off.",
"item": "First home buyer concession"
}
],
"buyer_type": "first_home",
"caveats": [
"Assumes you are an Australian citizen or permanent resident.",
"You must never have owned residential property in Australia (nor your spouse or partner).",
"For a home, you must move in within 12 months of settlement and live there for 12 months in a row."
],
"concession": 22640.25,
"concession_name": "First home buyer concession",
"contract_date": "2026-11-12",
"effective_rate_pct": 1.153,
"foreign": false,
"foreign_surcharge": 0,
"general_duty": 32437,
"price": 850000,
"price_source": "input",
"property_type": "established",
"rates": {
"effective_from": "2026-07-01",
"version": "NSW-duty-2026-07-01"
},
"state": "NSW",
"total_duty": 9796.75
}
}