Real discounts and fake ones: the 30-day rule

What the rule requires

When a shop announces a price reduction it must also show the lowest price it charged for that product in the preceding thirty days, and the discount must be calculated from that figure, not from some notional list price. The rule comes from an EU directive and has applied in Italy since 2023.

It exists to kill the oldest trick in retail: raising a price a few days before the sales so it can then be "discounted" back to where it already was. The rule makes that pointless, because the reference stays the lowest price of the previous month.

There are two sensible carve-outs: quickly perishable goods are excluded, and for an item on sale for less than thirty days the shorter actual period is used.

How to read it on the page

On well-built sites the line is there, in small type, under the price: "lowest price in the last 30 days" followed by an amount. That is the number to compare with today’s price. If it matches the discounted price, there is no discount: that is simply the usual price.

The big struck-through number beside it, by contrast, is often a price nobody ever paid: it can be the manufacturer’s recommended price, a theoretical list price or the launch price. Showing it is not forbidden, but it is the least useful information on the page.

In staged reductions — the familiar "extra discount on sale prices" — the reference stays the price before the campaign began, not the previous step: otherwise every further cut would look bigger than it is.

What the rule does not cover

It does not govern comparisons with other shops ("elsewhere it costs X"), nor personalised or members-only prices, nor limited-quantity offers when they are not presented as a reduction. And it does not stop a product from simply being expensive: the rule guarantees the discount is real, not that the price is good.

Then there is the legitimate but unlovely case of the early markup: if the price rises more than thirty days before the campaign, the reference moves with it. Guarding against that means looking at a longer price history, not at the thirty days.

Checking it in two minutes

The practical method is simpler than it sounds, and worth using only on purchases that matter:

• find the thirty-day lowest-price line and compare it with today’s price: if it is missing on a product advertised as reduced, that is already a signal;
• check the same product at another shop, using the model code rather than the marketing name;
• for significant purchases look at a price history covering months, not weeks;
• be wary of stacked discounts presented as one percentage: two 20% reductions do not make 40%, they make 36%.

Where a coupon site fits in

A discount code acts on the price the shop displays, and cannot correct an inflated one. If the starting price is high, a 10% code only makes it less high: the right order is to check the price first, then apply the code.

That is why the discounts shown on this site are the ones the shop states in the promotion, not our own estimates: if a shop says "up to 70%", that "up to" is theirs and stays theirs.