Making an offer

Buying at auction in Australia

How an auction works from registration to the fall of the hammer, what binds you when you win, and how the rules on vendor bids, the reserve and passed-in properties differ in each state and territory.

The short answer

The property sells to the highest bidder once bidding reaches the seller's reserve price (VIC, QLD). There is no cooling-off period on a property bought at auction in any state or territory (VIC, NSW, QLD, WA, SA, TAS, ACT, NT). You can't make the contract subject to finance in Victoria, South Australia or Tasmania (VIC, SA, TAS), it can't be conditional on finance approval in Western Australia (Consumer Protection WA (Dept of Local Government, Industry Regulation and Safety), verified 22 Oct 2026), and the NT auction contract is unconditional (Northern Territory Government, verified 12 Aug 2026). So finance, the building inspection and the contract review all have to be finished before you bid, not after.

How an auction runs, step by step

1. Registering

In NSW, Queensland, South Australia and the ACT you must register before you bid and show proof of identity (NSW, QLD, SA, ACT); in Victoria and Tasmania the auctioneer must tell bidders they will be identified on request (VIC, TAS). The WA and NT government pages describe no registration step.

2. The rules on display

The auction rules or conditions must be on display for at least 30 minutes before the auction in Victoria and the ACT (VIC, ACT), and before and during it in NSW and Tasmania (NSW, TAS). Read them before bidding starts.

3. Vendor bids

A vendor bid is made on the seller's behalf (Consumer Affairs Victoria, verified 30 Jul 2026). The rules differ: it is made only by the auctioneer and announced in Victoria (Consumer Affairs Victoria, verified 30 Jul 2026); limited to one in NSW (NSW Department of Customer Service (in collaboration with NSW Fair Trading), verified 12 Aug 2026) and one in the ACT (ACT Legislative Assembly (via AustLII consolidated text), verified 12 Aug 2026); up to 3, each below the reserve, in South Australia (Consumer and Business Services, South Australia, verified 22 Oct 2026); only up to the reserve in Queensland, each disclosed (Queensland Government (Office of Fair Trading), verified 12 Aug 2026), and up to the reserve in WA, with the number shown in the conditions of sale (Consumer Protection WA (Dept of Local Government, Industry Regulation and Safety), verified 22 Oct 2026). In the NT the seller may bid personally or have someone bid for them, and the auctioneer must announce it (Northern Territory Government, verified 12 Aug 2026).

4. Dummy bidding

Dummy bidding is illegal in Victoria, NSW, South Australia, Tasmania and the ACT (VIC, NSW, SA, TAS, ACT), with court penalties of up to $55,000 for an individual in NSW (NSW Department of Customer Service (in collaboration with NSW Fair Trading), verified 12 Aug 2026), a maximum of $20,000 in South Australia (Consumer and Business Services, South Australia, verified 22 Oct 2026) and a maximum of 100 penalty units in the ACT (ACT Legislative Assembly (via AustLII consolidated text), verified 12 Aug 2026). The Queensland, WA and NT government auction pages do not mention it.

5. The reserve

Victoria now requires the agent to publish the reserve at least 7 days before auctions held on or after 16 October 2026 (Consumer Affairs Victoria, verified 27 Sep 2026), under the Consumer Legislation Amendment Act 2026, assented to on 8 September 2026 (Parliament of Victoria, verified 27 Sep 2026); any change to it restarts the 7-day period (Consumer Affairs Victoria, verified 27 Sep 2026). In the other states with a stated rule, bidders aren't told the figure: in NSW it is usually not disclosed (NSW Government, verified 22 Oct 2026), in Queensland the auctioneer must not disclose it (Office of Fair Trading Queensland, verified 22 Oct 2026), in WA it is not disclosed to bidders (Consumer Protection WA (Dept of Local Government, Industry Regulation and Safety), verified 22 Oct 2026), in South Australia the vendor is not required to disclose it (Government of South Australia (Attorney-General's Department), verified 12 Aug 2026) and in the NT only the agent, auctioneer and owner know it (Northern Territory Government, verified 12 Aug 2026).

Once bidding reaches the reserve the property is 'on the market' and will sell to the highest bidder (VIC, QLD).

6. When the hammer falls

The winning bidder signs the contract and pays the deposit straight away in NSW, South Australia and the ACT (NSW, SA, ACT); in WA the bidder signs immediately (Consumer Protection WA (Dept of Local Government, Industry Regulation and Safety), verified 22 Oct 2026) and the deposit is due at the close of the auction (Consumer Protection WA (Dept of Local Government, Industry Regulation and Safety), verified 22 Oct 2026); in Victoria the contract binds once both sides have signed in the displayed terms (Consumer Affairs Victoria, verified 30 Jul 2026). The deposit is usually about 10% of the price (VIC, NSW, SA, WA), so have it ready in a form the agent accepts before the day. In NSW a buyer who can't complete loses the deposit and may be liable for the seller's damages (NSW Government, verified 22 Oct 2026).

7. If it's passed in

If bidding stops below the reserve, the property is passed in (VIC, NSW, WA, ACT). The highest bidder gets the first chance to negotiate with the seller in Victoria and the ACT (VIC, ACT), and generally in NSW (NSW Government, verified 22 Oct 2026).

A deal struck soon after a passed-in auction can still carry no cooling-off: on exchange the same day in NSW (NSW Department of Customer Service (in collaboration with NSW Fair Trading), verified 12 Aug 2026), before midnight that day for someone who bid in South Australia (Consumer and Business Services, South Australia, verified 22 Oct 2026), before 5pm on the second business day for a registered bidder in Queensland (Queensland Government (Office of Fair Trading), verified 12 Aug 2026), and on the same day for a registered bidder in the ACT (Access Canberra, verified 22 Oct 2026).

The rules in each state and territory

Each cell states only what its source says; a cell that says a page doesn't cover a topic means Delora found no official statement on it, not that no rule exists. Each state's page has the detail.

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Where buyers get caught out

• A pre-auction offer accepted less than three clear business days before a Victorian auction carries no cooling-off period (Consumer Affairs Victoria, verified 30 Jul 2026), even though it is not made at the auction itself.
• In South Australia it is the other way round: a successful pre-auction offer does carry cooling-off unless the buyer waives it, and the waiver needs an independent legal practitioner's signature (Government of South Australia (Attorney-General's Department), verified 12 Aug 2026).
• A Queensland auctioneer must disclose every vendor bid, and vendor bids stop once bidding reaches the reserve (Queensland Government (Office of Fair Trading), verified 12 Aug 2026): until then, a rising price is not proof of another buyer.

Auction rules by state

• Buying at auction in Victoria
• Buying at auction in New South Wales
• Buying at auction in Queensland
• Buying at auction in Western Australia
• Buying at auction in South Australia
• Buying at auction in Tasmania
• Buying at auction in the ACT
• Buying at auction in the Northern Territory

Before the day, see before-auction due diligence and auction versus private sale; for the rest of a purchase state by state, see buying a home by state.

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Common questions

Is there a cooling-off period at an auction in Australia?

No. In every state and territory, a property bought at auction has no cooling-off period, and several states extend that to a contract signed soon after a passed-in auction.

How much deposit do I pay at auction?

Usually about 10% of the price, paid when you sign. Victoria sets no amount by law; check the contract or conditions of sale for the amount and how it can be paid.

What is a vendor bid?

A bid the auctioneer makes for the seller, below the reserve. The number allowed differs: one in NSW and the ACT, up to three in South Australia, and up to the reserve in Queensland and WA. In the NT the seller may bid personally.

What happens if a property is passed in?

It hasn't sold. In Victoria and the ACT the highest bidder gets the first chance to negotiate with the seller, and generally in NSW too. A contract signed soon afterwards may still have no cooling-off period.

Practical checklist

Auction-day checklist

• 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 the seller to change before the auction?
• Is my finance approval good for this property, this price and this settlement date?
• What happens to my deposit if my finance or the valuation falls through after I win?

Official resources

• Consumer Affairs Victoria: buying property at auction
• NSW Government: buying property at an auction
• Queensland Government: auctioning a property
• Consumer Protection WA: buying property at auction
• SA Government: home sales, offers and auctions
• CBOS Tasmania: property auctions
• Civil Law (Sale of Residential Property) Act 2003 (ACT)
• NT Government: real estate auctions

Sources and methodology

• Buying property at auction — Consumer Affairs Victoria (retrieved 30 Jul 2026, last checked 7 Aug 2026). Licence: CC BY 4.0
• Auctioning a property — Queensland Government (Office of Fair Trading) (retrieved 12 Aug 2026). Licence: Queensland Government content, reproduced for research/citation purposes
• Buying property at an auction — NSW Department of Customer Service (in collaboration with NSW Fair Trading) (retrieved 12 Aug 2026). Licence: NSW Government content, reproduced for research/citation purposes
• Cooling-off period for residential property contracts (for buyers only) — Queensland Government (Office of Fair Trading) (retrieved 12 Aug 2026). Licence: Queensland Government content, reproduced for research/citation purposes
• Home buyers glossary | Consumer Protection, Western Australia — Consumer Protection WA (Dept of Local Government, Industry Regulation and Safety) (retrieved 7 Aug 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
• Property auctions — Consumer, Building and Occupational Services (Tasmania) (retrieved 12 Aug 2026). Licence: Tasmanian Government content, reproduced for research/citation purposes
• Civil Law (Sale of Residential Property) Act 2003 | ACT Legislation Register — ACT Parliamentary Counsel's Office (retrieved 7 Aug 2026). Reuse terms: see the publisher's site
• Real estate auctions — Northern Territory Government (retrieved 12 Aug 2026). Licence: Northern Territory Government content, reproduced for research/citation purposes
• Buying property at auction | Consumer Protection, Western Australia — Consumer Protection WA (Dept of Local Government, Industry Regulation and Safety) (retrieved 22 Oct 2026). Reuse terms: see the publisher's site
• Buying property at an auction | NSW Government — NSW Government (retrieved 22 Oct 2026). Licence: CC BY 4.0
• Reality Check: a real estate guide for buyers and sellers in the ACT (third edition) — Access Canberra (retrieved 22 Oct 2026). Reuse terms: see the publisher's site
• Civil Law (Sale of Residential Property) Act 2003 (ACT) -- ss.29, 30, 32 — ACT Legislative Assembly (via AustLII consolidated text) (retrieved 12 Aug 2026). Licence: AustLII consolidated legislation text, reproduced for research/citation purposes
• 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
• New changes to property sales and underquoting laws | Consumer Affairs Victoria — Consumer Affairs Victoria (retrieved 27 Sep 2026). Licence: CC BY 4.0
• Consumer Legislation Amendment Act 2026 (Vic), No. 36 of 2026 — Act as made — Parliament of Victoria (retrieved 27 Sep 2026). Licence: Victorian legislation — free reuse per legislation.vic.gov.au copyright notice
• Industry Q&As: New changes to property sales and underquoting laws | Consumer Affairs Victoria — Consumer Affairs Victoria (retrieved 27 Sep 2026). Licence: CC BY 4.0
• Auctioning a property | Queensland Government — Office of Fair Trading Queensland (retrieved 22 Oct 2026). Licence: CC BY 4.0
• Real estate auctions | NT.GOV.AU — Northern Territory Government (retrieved 22 Oct 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.