South Australia · Auctions and price guides
Auctions and price guides in South Australia
The prescribed minimum advertising price, the 110% range limit, vendor bids, bidder registration and what changes on auction day in South Australia.
Status: Every fact on this page was read on legislation.sa.gov.au's, SA.GOV.AU's and Consumer and Business Services' own page text on 16 September 2026 (search-snippet verification against the pages listed under Sources): the prescribed minimum advertising price, the 110% range limit, the section 24A penalty, the three-vendor-bid rule, bidder registration and the January 2014 identifier rule. Still to be read on the Act: the carve-out for a statement of the vendor's actual acceptable price, and whether a reserve may sit above the advertised price; the text of the January 2025 bidders guide was not returned. CBS's current forms date from January and September 2025, and nothing on its site announces a change to these rules.
South Australia regulates the price guide by putting a floor under it. An agent may not advertise a likely price below the prescribed minimum advertising price. That floor is the higher of the agent's own estimate and the price the vendor has said is acceptable, both as written in the sales agency agreement. A range may not stretch more than 110% from bottom to top. On auction day there is no cooling-off, every bidder is registered, the vendor gets up to three announced bids through the auctioneer, and the deposit is usually at least 10%.
What a price guide may say
The Land and Business (Sale and Conveyancing) Act 1994 defines the prescribed minimum advertising price from the sales agency agreement. It takes the agent's estimate of the selling price and the price sought by or acceptable to the vendor, and the greater is the floor. When marketing for a vendor, the agent and their sales representatives must not put forward a likely price below it. Nor may they give a likely price range whose upper limit exceeds 110 per cent of the lower limit.
SA.GOV.AU's plain-words version for sellers: agents must not promote a price below their estimated selling price or the vendor's acceptable price, whichever is higher.
One carve-out matters when reading a listing. A statement of the price the vendor actually wants is not a "likely price" under the Act, provided it matches the acceptable price in the agency agreement at the time. Such a listing states a position, not an estimate. What an offers over figure can mean is covered in the national guide.
Underquoting
underquoting in South Australia is a likely price below the prescribed minimum, or a range wider than the 110% limit. The rule was written into the Act by the Statutes Amendment (Real Estate Industry Reform) Act 2007, and Consumer and Business Services regulates land agents. Section 24A of the Act carries a maximum penalty of $20,000 or imprisonment for 1 year.
To report a suspected breach, contact CBS: report a business online or call 131 882. The floor sits in a document the buyer never sees, the sales agency agreement. A complaint therefore rests on what was advertised, what was said at inspections and what the property sold for. Keep the listing and the agency's messages.
Reforms in train
No reform to the price-guide or auction rules was found announced or commenced in this research. The price rules date from the 2007 reforms, the bidder-identifier rule from January 2014, and the current prescribed bidders guide, Form 4, is dated January 2025. Anything newer would appear on the CBS site.
On auction day
Any person who intends to bid at an auction for residential property must register, by giving the agent their details and proof of identity. That can be done any time before the auction, such as at an inspection, or on the day. Since January 2014 every bidder has a unique identifier, such as a number, letter or colour. The auctioneer must audibly announce each bid as taken from that identifier. Auctioneers must also keep accurate records of who bid, how much, and the outcome: passed in, held over or successful.
It is illegal for the vendor, or a person acting on their behalf, to bid at the auction; that is dummy bidding. The vendor is allowed up to three vendor bids, made by the auctioneer, which must be below the reserve and clearly announced as vendor bids. Below the reserve the property is passed in. Whether the reserve may sit above the advertised price was not returned in this research; the Act and the bidders guide are the places to check.
There is no cooling-off period if the property is bought at auction. The deposit is usually a minimum of 10% of the price bid, and auction conditions are generally a 10% deposit and 30-day settlement. Everything a buyer would check in the cooling-off period, the Form 1 above all, has to be checked before the auction; the contracts page lists those checks.
Reading a guide against the sales
A South Australian guide tells you the floor the agent and vendor agreed to, and no more. The evidence sits in the recorded comparable sales nearby: similar type, similar size, similar condition, as recent as the evidence allows. Those sales support a fair-value range, never a single figure. Build the range first, then see where the guide sits against it: under, within or above. The guide to building a range sets out the method, and the offers-over guide covers the campaign's language. A Property Decision Report does this for one property before auction day: the range, where the guide sits, and a walk-away number set before the bidding starts.
Sources
- Land and Business (Sale and Conveyancing) Act 1994, current authorised version — checked 16 September 2026. Read on the register's current version (15 January 2026) on 16 September 2026: section 24A, the prescribed minimum advertising price, the 110% range limit and the maximum penalty of $20,000 or imprisonment for 1 year. The carve-out for a statement of the vendor's actual acceptable price and the reserve rule are still to be read.
- SA.GOV.AU, offers, auctions and buying off the plan — checked 6 September 2026. Snippet-verified from this build environment; open before the page is indexed. Registration, vendor bids, dummy bidding, the deposit and no cooling-off.
- SA.GOV.AU, selling your home — checked 6 September 2026. Snippet-verified from this build environment; open before the page is indexed. The consumer wording of the price rule.
- Legal Services Commission of South Australia, Law Handbook, auctions — checked 6 September 2026. Snippet-verified from this build environment; open before the page is indexed. The unique-identifier rule and the usual auction conditions.
- Consumer and Business Services, bidders guide (Form 4, January 2025) — checked 16 September 2026. The current prescribed form (January 2025); its text was not returned in this build environment. CBS lists no change to the price-guide or auction rules.
- SA.GOV.AU, working in real estate — checked 6 September 2026. Snippet-verified from this build environment; the auctioneer record-keeping rule, attribution between this page and the selling page uncertain.
- SA.GOV.AU, solving a problem with a real estate agency — checked 6 September 2026. Snippet-verified from this build environment; open before the page is indexed. How to report an agent to CBS.
Last updated 16 September 2026 · reviewed by The Buyers Grail editorial (agency page text checked 16 September 2026).
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