You remember last week's price. The law checks something else.

The new law checks supermarket costs. You check your memory.

Australia's new supermarket pricing law sounds like it should make grocery shopping feel fairer straight away. Coles and Woolworths can face big penalties if prices are found to sit outside a reasonable margin compared with the cost of supply.

That matters. It puts the biggest supermarkets under more pressure and gives the ACCC another lever to pull. But it also creates a gap between what the law measures and what shoppers actually feel at the checkout.

The law looks at retailer costs. You look at the shelf tag and think, hang on, wasn't this cheaper last week? Those are two very different tests. One belongs to regulators. The other happens in your head while someone is blocking the pasta sauce with a trolley parked sideways. Classic supermarket theatre.

Why high prices can still clear the legal bar

The new rules focus on whether a price is significantly excessive compared with the retailer's costs plus a reasonable margin. That means the ACCC has to look at the cost side of the equation, rather than only the number on the shelf.

If a harvest goes badly, freight gets more expensive, suppliers raise prices, or waste risk increases, a higher shelf price may have a legitimate explanation. It can still feel painful. It can still wreck your weekly budget. But a painful price is not automatically an unlawful one.

That is why the wording matters. The government has deliberately avoided a fixed percentage or dollar threshold for excessive pricing. A hard number could be gamed. A flexible test gives regulators room to look at the full picture, but it also means enforcement will never feel as simple as shoppers want it to feel.

Your grocery price memory is doing too much work

Most shoppers do not know what a supermarket paid for a product. You do not see supply costs, rebates, freight bills, spoilage risk, or category margins. What you do have is memory: what you think the item cost last week, last month, or the last time it was on special.

That memory is useful, but it is also messy. You remember the sale price as the normal price. You forget the quiet price rise that happened between shops. You notice the products that jump, and forget the ones that sat still. You might remember that peanut butter used to be cheaper, but not whether it was $5.50, $6.20, or a half-price special you grabbed once in April.

That is the shopper problem the law does not solve. Even if the ACCC is watching the big supermarkets, you still need a way to check today's price against actual recent prices, instead of trusting a fuzzy memory.

What to check before trusting a shelf tag

You cannot run a legal margin test in the aisle. You can run a practical shopper test. Before you treat a price as good, bad, or suspicious, check the signals you can actually see.

1. Check the recent price history before assuming a special is genuinely low.
2. Compare the same or similar product across Coles, Woolworths, and ALDI where prices are available.
3. Watch regular buys so you notice actual drops instead of relying on memory.
4. Scan the barcode in store when you want a quick product-level check.
5. For bigger shops, compare your list before deciding whether an extra store stop is worth it.

Where Discount Trolley helps

Discount Trolley is built for the memory problem. You can search products and compare current prices across Coles, Woolworths, and ALDI where data is available. You can check recent price history to see whether a special is actually low compared with recent prices. You can watch regular buys and get alerts when prices drop.

If you are already in the supermarket, barcode scanning can help you look up available product price information on the spot. If you are planning a larger shop, lists and Smart Split can help you see whether splitting a shop across stores may be worth considering.

To be clear: Discount Trolley does not decide whether a price is legally excessive. It does not cover every product at every store, and it cannot guarantee savings. What it does is give you a better record than memory, so you can decide with more confidence before the item lands in the trolley.

The practical takeaway

The new law may make supermarkets feel more watched, and that pressure is useful. But your grocery bill turns up every week, not after a regulator finishes a long investigation.

So treat the law as the backstop, not the shopping strategy. Keep an eye on price history. Compare stores where it makes sense. Watch the items you buy again and again. If a price feels off, check it before you trust the feeling.

Your memory is doing its best. It is just not a spreadsheet.

Questions shoppers still ask