Making an offer
Buying at auction in South Australia
The SA auction rules from registration to the fall of the hammer: vendor bids, the reserve, the deposit, cooling-off and what happens if a property is passed in, each cited to Consumer and Business Services and the SA Government.
Key points
- Cooling-off: None at auction or later the same day; a pre-auction offer has cooling-off unless waived.
- At the hammer: Sign immediately after the hammer; deposit usually around 10%, paid immediately.
- Vendor bids: Up to 3, made by the auctioneer, each below the reserve and announced.
- If passed in: The vendor may negotiate with a bidder or put it on the open market; no cooling-off on a contract with someone who bid, made before midnight that day.
SA auction rules at a glance
Cooling-off: None at auction or later the same day; a pre-auction offer has cooling-off unless waived (Government of South Australia (Attorney-General's Department), verified 12 Aug 2026).
Rules as at the date on each citation, from Consumer and Business Services and the SA Government. The bidders' guide is the form prescribed under the Land and Business (Sale and Conveyancing) Act 1994, version January 2025.
Registering to bid
Bidders must register with the agent, giving their details and proof of identity, or authorise someone else in writing to bid for them (Government of South Australia (Attorney-General's Department), verified 12 Aug 2026).
The contract and its conditions
An auction sale is unconditional: the contract can't be made subject to finance (Government of South Australia (Attorney-General's Department), verified 12 Aug 2026).
The buyer's information notice (Form R3) must be available at least 3 business days before the auction, and at the auction site at least 30 minutes before it starts (Government of South Australia (Attorney-General's Department), verified 12 Aug 2026).
The reserve price
The vendor sets a reserve price but is not required to disclose it to bidders (Government of South Australia (Attorney-General's Department), verified 12 Aug 2026).
Vendor (seller) bids
The vendor may have up to 3 bids made on their behalf by the auctioneer; each must be announced as a vendor bid and be less than the reserve price (Consumer and Business Services, South Australia, verified 22 Oct 2026).
Dummy bidding
It is against the law for the vendor, or anyone acting on the vendor's behalf, to bid at the auction. This is dummy bidding, and it can attract a maximum penalty of $20,000 (Consumer and Business Services, South Australia, verified 22 Oct 2026).
When the hammer falls: signing and the deposit
Under the prescribed conditions, the contract is signed by or for the buyer and the vendor immediately after the fall of the hammer, and the deposit is paid immediately too unless both agree otherwise in writing before the auction starts (Consumer and Business Services, South Australia, verified 22 Oct 2026).
The deposit is usually around 10% of the price (Consumer and Business Services, South Australia, verified 22 Oct 2026).
Generally the auction conditions are a 10% deposit and 30-day settlement, though some terms can be negotiated with the agent before the auction (Government of South Australia (Attorney-General's Department), verified 12 Aug 2026).
Cooling-off
There is no cooling-off period for a property bought at auction, or bought after the auction on the same day. A successful offer made before the auction does carry a cooling-off right unless the buyer waives it, and the waiver needs an independent legal practitioner to sign a prescribed form (Government of South Australia (Attorney-General's Department), verified 12 Aug 2026).
If the property is passed in
If bidding doesn't reach the reserve, the vendor may choose not to sell, negotiate with a bidder, or put the property on the open market (Government of South Australia (Attorney-General's Department), verified 12 Aug 2026).
If the property is passed in and someone who bid at the auction signs a contract for it before midnight on the auction day, that contract has no cooling-off period (Consumer and Business Services, South Australia, verified 22 Oct 2026).
Before you bid: with no cooling-off period, finance, the building inspection and a conveyancer's or solicitor's review of the contract all have to be done before the auction.
For how auctions run everywhere, and every state side by side, see buying at auction in Australia. For cooling-off, the contract, the deposit and settlement on a private sale too, see buying a home in South Australia.
Common questions
Is there a cooling-off period at auction in South Australia?
There is no cooling-off period for a property bought at auction, or bought after the auction on the same day. A successful offer made before the auction does carry a cooling-off right unless the buyer waives it, and the waiver needs an independent legal practitioner to sign a prescribed form.
What do I sign and pay when I win an auction in South Australia?
Under the prescribed conditions, the contract is signed by or for the buyer and the vendor immediately after the fall of the hammer, and the deposit is paid immediately too unless both agree otherwise in writing before the auction starts.
How do vendor bids work in South Australia?
The vendor may have up to 3 bids made on their behalf by the auctioneer; each must be announced as a vendor bid and be less than the reserve price.
Practical checklist
Before an auction in South Australia
- Finance approved for this property and your limit, not just pre-approval in principle
- Building and pest inspection, and strata records for a unit, done before the day
- Contract and vendor disclosure read by your conveyancer or solicitor, with any changes asked for in writing before the auction
- Your walk-away limit written down, and the bidding plan for whoever bids
- Proof of identity for registration, and a letter of authority if bidding for someone else or a company
- The deposit ready in a form the agent accepts, confirmed with the agent beforehand
- Arrive early to read the rules or conditions on display and hear the auctioneer's opening statements
- If you win: get a copy of the signed contract, tell your lender, and arrange insurance from the date your contract says
Questions for a professional
- Is there anything in this contract or the conditions of sale I should ask to change before the auction?
- What happens to my deposit if my finance falls through after I win?
Official resources
- SA Government: home sales, offers and auctions
- Consumer and Business Services: bidders' guide (form 4)
Important limitations: General information about SA auction rules, not legal or financial advice and not a bidding strategy. Rules change; each citation shows when Delora last checked its source, and Consumer and Business Services and the SA Government is the authority. Have a conveyancer or solicitor review the contract before auction day.
Sources and methodology
- Bidders' guide: guide to the sale of residential property by auction (form 4, January 2025) — Consumer and Business Services, South Australia (retrieved 22 Oct 2026). Reuse terms: see the publisher's site
- Offers, auctions and buying off the plan — Government of South Australia (Attorney-General's Department) (retrieved 12 Aug 2026). Licence: CC BY 4.0
Figures on this page are drawn from Delora's local knowledge graph, refreshed from these primary sources and checked for changes on a regular schedule. If a figure here looks out of date, the official source above is always the authority — please let us know.
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