In plain English, with sources
What the law says.
Supermarket prices aren't just a matter of opinion any more. Here's what's now law, what a court has found, and what the regulator concluded. Newest first.
1 July 2026
Excessive prices are against the law
Since 1 July 2026, very large supermarkets such as Coles and Woolworths can't charge prices that are excessive compared with the cost of supply plus a reasonable margin. The ACCC enforces it.
The penalty is the greatest of $10 million, three times the benefit gained, or 10% of the previous 12 months' turnover.
That's why this site lines shelf prices up against what it costs to get the food there: it's the comparison the law itself makes.
“it will be illegal for very large retailers such as Coles and Woolworths to charge prices that are excessive, when compared to the cost of supply plus a reasonable margin.”
14 May 2026
Coles' "Down Down" discounts were found misleading
The Federal Court found Coles advertised discounts off higher prices that had only been in place for short periods. In most cases the court looked at, the higher price had lasted around four weeks.
Justice O'Bryan said a product would generally need to stay at the higher price for 12 weeks before shoppers could reasonably see a later discount as genuine. He accepted the price rises themselves were commercially justified.
The penalty hasn't been set yet. A separate ACCC case against Woolworths' "Prices Dropped" discounts went to trial in April and May 2026.
21 Mar 2025
The ACCC's supermarket inquiry
The ACCC found Coles and Woolworths are among the most profitable supermarket businesses compared with their peers overseas, and that Aldi, Coles and Woolworths all increased their margins over five years.
It found most price rises reflected higher costs, but that at least some increases had become extra profit. It stopped short of finding that the supermarkets had overcharged.
It described the market as a highly concentrated oligopoly, and recommended the big three publish their prices online and give price comparison tools access to them.
1 Apr 2025
The Food and Grocery Code became mandatory
The code that governs how supermarkets deal with their suppliers became compulsory for the biggest supermarkets, with multi-million-dollar penalties for serious breaches. The government is also strengthening the Unit Pricing Code, including on shrinkflation.
This is a plain-English summary, not legal advice.