Price-guide research raises questions as NSW and Victoria tighten disclosure laws

New research has highlighted the limits of advertised property price guides just as NSW prepares to make them compulsory and Victoria begins requiring auction reserves to be published.

A report prepared for the Australian Property Institute with property data firm Homer examined 102,681 Victorian residential sales in the year to June 30, 2026. The Australian Financial Review reported on Tuesday that only 43 per cent sold within the first price guide shown to buyers.

That does not mean every sale outside its range involved underquoting. A guide is an estimate produced before the final result is known, and prices can move in either direction as a campaign unfolds. Competition between buyers, changing market conditions, rejected offers and new comparable sales can all alter expectations.

However, the finding shows why buyers should not treat the first advertised range as a valuation, a promise or a reliable measure of their maximum likely spending.

What the Victorian finding means

Consumer Affairs Victoria says a sale above the advertised range is not, by itself, proof of underquoting. Underquoting occurs when an agent advertises below the seller’s known asking or reserve price, below an offer already rejected as too low, or below the agent’s current estimated selling price.

Agents must update their pricing when relevant information changes. This distinction matters because a strong result can be legitimate, while an outdated or knowingly low guide may breach the law.

The new research measured the difference between the first guide and the final result. It therefore provides a useful test of how accurately campaigns begin, but it does not establish the reason for every difference or determine which agents broke the law.

For buyers, the practical conclusion is simpler: an initial guide is one piece of evidence, not the whole budget calculation.

States are taking different approaches

Victoria’s latest transparency rules began on October 1. Agents must now use a Property Price Statement, publish the final price after a sale becomes unconditional and disclose the seller’s reserve at least seven days before an auction or fixed-date sale.

For auctions and fixed-date campaigns held from October 16, the event cannot proceed unless the reserve has been published for the full seven-day period. This gives buyers an important number that was previously unavailable, although it arrives relatively late in the campaign.

NSW rules beginning on November 17 will end advertisements that only say “price on inquiry”. Agents will have to include a selling price or range, use three comparable sales when forming an estimate and update online advertising within one business day when the displayed figure no longer complies with the law.

Maximum underquoting penalties in NSW will rise to $110,000 or three times the agent’s commission, whichever is greater. From February 8, 2027, a Statement of Information explaining the estimate and comparable sales will also be required.

Queensland is moving in the opposite direction for now. Domain reported on Tuesday that the Queensland Government had ruled out equivalent reforms, saying its auction framework already contained strong safeguards. Queensland law prevents agents and auctioneers from disclosing price guides for residential auction properties, while private-treaty advertisements can appear without a public price.

That leaves buyers moving between states facing markedly different information before inspections and auctions.

How to test a guide

Buyers should build their own range before spending money on reports, legal work or travel. Useful checks include:

• recent settled sales for genuinely similar homes, rather than suburb-wide medians
• land size, bedrooms, parking, condition and renovation quality
• the latest price statement and any revisions during the campaign
• written offers rejected as too low, where that information is disclosed
• current competition and whether nearby properties remain unsold.

Keep screenshots and copies of price documents if the advertised range changes. A result above the guide is not automatically unlawful, but records can help a regulator assess whether the estimate was reasonable and updated when required.

What it means for you

• Treat the first guide as an estimate, not a spending target.
• NSW buyers will see mandatory advertised prices from November 17.
• Victorian auction buyers should check the published reserve seven days before the sale.
• Base your limit on comparable settled sales and finance approval, not campaign momentum.