Poland requires every promotional tag to carry the lowest price from the thirty days before the reduction, and in January two marketplaces paid for skipping that step. As of 10 November 2026 the same obligation follows the discount into paid placements on other sites, which is where most product feeds quietly fail. The penalty is never about how deep the discount was. It is about whether the label can be reconstructed after the fact.
What The Rule Actually Requires
The mechanics are narrow and unforgiving. The discount percentage is calculated from the lowest price of the last thirty days, not from a regular or recommended price, and a product that has been on sale for less than thirty days must show the lowest price since sales began （Easytools）. A crossed-out figure on its own is not enough: the label has to name the reference, sit beside the price and stay legible, which rules out the footnote and the tooltip that many templates still use.
The reach is the part that catches retailers by surprise. The obligation applies wherever the promotion is presented, including advertising on third-party sites （ZEST）. A product feed and a creative can therefore disagree without anyone noticing internally, and the disagreement is the violation, not the intent behind it.
Two Penalties And What They Establish
Zalando was fined 30.95 million zloty, about 7.3 million euros, in January 2026. Months after the rules took effect, shoppers on its Polish site still could not see the lowest thirty-day price, including in external ads and product listings, and once the price did appear the authority found it unreliable: the reference value changed from day to day while the regular price stayed the same （ZEST）. Temu was fined 5.91 million zloty, about 1.4 million euros, in the same month for not always showing the lowest thirty-day price when advertising a discount, sometimes showing it only for selected variants and with a misleading value. It changed its practices during the proceedings and the fine still came.
| Case | Authority | Amount | What was established |
|---|---|---|---|
| Zalando, Poland | UOKiK | 30.95 million zloty | Reference price must be stable and visible, including in external ads |
| Temu, Poland | UOKiK | 5.91 million zloty | Variant-level display is not a defence when the headline is misleading |
| Shein, France | DGCCRF | 40 million euros | 57 per cent of checked offers gave no real reduction |
| Black Red White, Poland | UOKiK, opened 2026 | Up to 10 per cent of turnover | A promo price of 989 zloty above a 899 zloty thirty-day low |
The French case shows what a price history audit produces. The DGCCRF found that Shein had raised some prices right before discounting them and ignored earlier promotions when setting reference prices, and in 57 per cent of the offers checked the advertised promotion gave shoppers no real reduction （ZEST）. Two more fines followed in June 2026 for other consumer-law breaches. Once an authority starts reading a price file, it tends to keep reading it.
Four More Cases Are Still Open
In spring 2026 the Polish authority opened proceedings against a furniture chain, a convenience format, a clothing retailer and a fashion chain. In one example a promotional price of 989 zloty sat above the product's lowest thirty-day price of 899 zloty; in another, advertising showed a crossed-out price with an asterisk instead of the actual thirty-day low; in two more, the lowest price was missing from price tags or shown incorrectly online （Easytools）. Each could face a fine of up to 10 per cent of annual turnover, which is a different order of magnitude from the 20,000 to 40,000 zloty the trade inspection can impose directly.
The pattern across all six cases is the same, and it is not about discount depth. Retailers that got into trouble had a price history that could not be reproduced, a feed that disagreed with a landing page, or a template that treated the reference as decoration. None of those failures requires bad faith; they require a calendar in which nobody owns the reference number.
Why the feed and the page drift apart
A price file is maintained by a commercial team, a product page by a content team and a paid placement by an agency, and the three are reconciled on different days. The thirty-day reference is a rolling calculation, so it changes every morning whether or not anyone touches the page. That is exactly how a reference value starts moving day to day while the shelf price stays still, which is one of the findings the Polish authority used against a marketplace.
What an audit trail looks like
An audit trail is not a report. It is a dated record, per product and per variant, of the price actually charged each day, the thirty-day low computed from it, and a copy of the creative that carried the discount on every surface where it ran. A retailer that can produce those three things for a given product on a given date is defensible even when the number is unflattering; one that cannot is exposed even when the discount was genuine.
A Five Step Check Before The Promotional Calendar Opens
The work is small if it happens before the calendar is locked and expensive if it happens after a complaint, because by then the reference number has already been published and copied into a feed. Five steps cover the failure modes that the enforcement record actually shows, and none of them requires new software beyond an export of the daily charged price. Run them in the order below, since each step depends on the file the previous one produced.
- Export the daily charged price for every SKU in the campaign for the previous forty-five days, and compute the thirty-day low from that file rather than from the price list.
- Compare the computed low with what the product page, the app and the paid creative display, product by product, variant by variant.
- Check packs listed for fewer than thirty days separately, because their reference is the lowest price since launch and not a thirty-day window.
- Confirm that the reference sits beside the price on mobile as well as on desktop, and remove any template that puts it in a footnote or a hover state.
- Freeze a dated copy of every creative and every feed snapshot, so that a later complaint can be answered with what was actually shown.
The field table is the part that survives a staff change. A reference number without a snapshot date cannot be defended six weeks later, and a snapshot without the computed low cannot show that the number was right when it was published.
What This Means For The Next Four Weeks
The promotional calendar for the year-end window is already open, and the thirty-day reference for a 27 November discount reaches back into late October. That window is fixed, which means a retailer that has not yet exported its daily prices is already working from memory. The practical consequence is that the audit has to run on the calendar that exists, not on the one that would have been easier to prove.
FAQ
Does the rule apply to a discount code as well as to a crossed-out price?
Yes. When a code is tied to a specific product, the lowest price from the preceding thirty days has to be visible once the code is applied in the cart, not only on the product page.
Is a stable reference price enough if it is lower than the regular price?
It has to be the lowest price actually charged in the window, so a reference that is stable but not the lowest is still a violation. Stability is a separate test from accuracy.
Who carries the penalty on a marketplace, the seller or the platform?
In practice the authority has pursued the platform for the display it controls, and sellers for the listings they publish. The safest assumption for a brand is that it owns the reference on any surface it pays for.
How much notice does a price change need before a campaign?
Enough for the thirty-day window to contain it. A discount announced on the day a price rises produces a reference that never existed, which is the pattern behind several of the open cases.
