How South Australia stamp duty is calculated in 2026

South Australia's stamp duty scheme has a feature the east-coast states do not: the first-home buyer concession is uncapped, but it only applies to new homes and vacant land. Buy an established 1960s villa in Prospect for $700,000 as a first-home buyer and you pay the same duty as an investor flipping the place next door. Buy a brand-new townhouse for $1.2 million and you pay zero. The price-cap states call this unfair; SA calls it housing-supply policy.

Here is how the brackets, the new-build exemption, and the off-the-plan concession actually combine on a 2026 contract.

The bracket schedule (everyone pays these unless a concession applies)

SA uses a single progressive schedule. Every dollar above a threshold is taxed at the rate for that band; the rate on the top band does not retroactively apply to the whole price. The 2026 schedule, sourced from RevenueSA, looks like this:

• Up to $12,000: $1.00 per $100.
• $12,001 to $30,000: $120 plus $2.00 per $100 over $12,000.
• $30,001 to $50,000: $480 plus $3.00 per $100 over $30,000.
• $50,001 to $100,000: $1,080 plus $3.50 per $100 over $50,000.
• $100,001 to $200,000: $2,830 plus $4.00 per $100 over $100,000.
• $200,001 to $250,000: $6,830 plus $4.25 per $100 over $200,000.
• $250,001 to $300,000: $8,955 plus $4.75 per $100 over $250,000.
• $300,001 to $500,000: $11,330 plus $5.00 per $100 over $300,000.
• Over $500,000: $21,330 plus $5.50 per $100 over $500,000.

Two things stand out compared to the bigger states. First, there is no headline rate concession for owner-occupiers, the way Queensland gives every PPR a price break. Second, the top marginal rate of 5.5% kicks in at $500,000, which by Adelaide standards is well inside the family-home band. The median established dwelling in metropolitan Adelaide ticked above $750,000 in 2025, so most non-first-home buyers in the city land squarely in the top bracket.

Worked example: $650,000, owner-occupier, established home

Take a $650,000 established three-bedroom in Findon, a typical 2026 Adelaide owner-occupier purchase. Walk through the top bracket only, since every dollar below $500,000 is already captured by the $21,330 base figure:

• Base at $500,000 threshold: $21,330.
• Amount over $500,000: $150,000.
• Duty on the excess: $150,000 / $100 = 1,500 units of $100, times $5.50 = $8,250.
• Total duty: $21,330 + $8,250 = $29,580.

On a $650,000 contract that is an effective rate of about 4.55%. No concession applies for an owner-occupier on an established home in SA. The same price as a first-home buyer on an established home is also $29,580. The same price as a first-home buyer on a new build is $0. The property type, not the buyer type, is what moves the needle in this state.

The new-build first-home exemption (uncapped, since 6 June 2024)

The state government scrapped the previous price caps on the first-home buyer stamp-duty relief in June 2024. The current rules:

• New homes and off-the-plan apartments:full exemption from stamp duty for first-home buyers, no price ceiling.
• Vacant land for a new build: full exemption from stamp duty for first-home buyers, no price ceiling.
• Established homes: no first-home buyer stamp-duty relief at all. The first-home buyer pays the same duty as an investor.

The uncapped exemption on new builds is the most generous first-home concession in the country at the top end. A first-home buyer purchasing a $900,000 new townhouse in Bowden saves the full $43,330 of duty on the day; the same buyer in NSW would have lost the concession well before $900k, and in VIC would never have qualified above $750k. Compare the price-band crossover logic in the NSW vs VIC comparison for a sense of how aggressive SA's pure-property-type rule is by national standards.

The First Home Owner Grant (FHOG), a separate $15,000 cash payment administered by RevenueSA, still applies on top of the stamp-duty exemption for eligible new builds under the FHOG price cap. The two work together rather than against each other. An eligible first-home buyer on a $650,000 new home therefore pays $0 duty and receives $15,000 cash, against a comparable buyer on a $650,000 established home who pays $29,580.

Off-the-plan apartment concession

Separate from the first-home buyer rules, SA also offers a partial duty concession on off-the-plan apartments for any buyer, including investors and non-first-home owner-occupiers. The concession discounts the dutiable value to exclude the portion of the contract attributable to construction not yet completed at the date of contract. In practice this can shave several thousand dollars off the duty bill on an early-stage off-the-plan apartment purchase, and the saving is largest when contracts are signed well before practical completion.

The relief is administered by RevenueSA on application; the conveyancer files the concession claim alongside the standard duty assessment. Worth raising with the conveyancer before settlement, since it is not auto-applied.

Foreign Ownership Surcharge (7%)

Foreign purchasers pay a 7% surcharge on residential property, called the Foreign Ownership Surcharge. The surcharge applies on top of the standard stamp duty and is calculated on the full purchase price, not the post-concession amount. SA's 7% sits below NSW's 9% and the 8% charged by VIC, QLD and TAS, but above the zero-surcharge regimes of ACT and NT.

A foreign buyer at $1 million in SA owes $70,000 of surcharge plus the standard $48,830 of duty, totalling $118,830. The first-home buyer new-build exemption does not apply to foreign purchasers, since the underlying first-home eligibility requires Australian citizenship or permanent residency.

How to run this on your specific contract

Articles work in clean numbers. Your contract has cents and a specific property type. The fastest way to a precise figure is the platform calculator, which carries the SA brackets verified against RevenueSA and toggles the new-build and off-the-plan rules correctly:

1. Enter the contract price and toggle the state to South Australia in the stamp duty calculator. Choose "new home", "off-the-plan" or "established" as the property type, because that choice is what flips the first-home result between $0 and the full schedule.
2. Compare against another state by switching the jurisdiction. The QLD calculation breakdown shows the equivalent logic for a Brisbane purchase, and is a useful reference if you are weighing an Adelaide-vs- Brisbane move.
3. Carry the duty into your upfront-cost stack alongside the deposit, conveyancing, building and pest, and LMI if applicable. The first-home buyer guide covers the full line-item walkthrough.

SA's stamp-duty scheme rewards a single choice harder than any other state: new versus established. A first-home buyer who can stretch from a $650,000 established place to a $700,000 off-the-plan apartment is roughly $30,000 better off on day one, before counting the FHOG. That is the lever the government built into the policy. Whether it suits your actual purchase depends on the contract in front of you, not the averages.