- Product
- Solution for
For Your Industry
- Partners
- Plans & Pricing
- Resources
The 30-day lowest price rule requires every EU retailer that announces a discount to calculate it from the lowest price it actually charged for that product in the 30 days before the reduction, and in the European Commission’s most recent Black Friday sweep, 30% of 314 online traders checked still got it wrong. Since the Court of Justice of the EU confirmed in 2024 that percentages, strike-through prices and “price highlight” claims must all trace back to that same 30-day low, compliance has stopped being a wording problem for the legal team and become a data problem for the pricing team. If you cannot prove what you charged, you cannot defend what you advertise.
The rule requires that any announcement of a price reduction shows the lowest price the trader itself applied to that product during at least the 30 days before the reduction, and that this lowest price is the reference for the discount. It comes from Article 6a of the Price Indication Directive (98/6/EC), inserted by the Omnibus Directive (EU) 2019/2161, which EU member states have applied since May 2022. It covers goods sold to consumers online and offline; digital services and B2B sales fall outside Article 6a, according to Talon.One’s summary of the directive.
Three details trip up most pricing teams. First, it is the lowest price in the window, not the last one. If a product sat at €99 for most of October but dropped to €89 for a weekend, €89 is the reference for a November discount. Second, it is your own price, not a competitor’s price or the manufacturer’s recommendation. Third, it applies to every format that signals a reduction: a crossed-out price, a percentage badge, a “was/now” label, a “you save €20” line or a “top deal” sticker.
A worked example from the Dutch ACM shows why this matters. In its fines against webshops, the regulator described a product advertised as “was €699, now €629”, when the same seller had sold it for €539 during a sale within the previous 30 days. Consumers saw a saving of €70. In reality the price had gone up by €90.
If a reduction cannot be traced back to your own genuine 30-day low, it is not a discount in the eyes of EU law, whatever the banner says.
The CJEU’s Aldi Süd judgment fixed what the discount must be calculated from, and Germany’s Federal Court of Justice then fixed how clearly the 30-day low must be shown. Together they closed the two loopholes retailers relied on most between 2022 and 2024.
In Case C-330/23, decided on 26 September 2024, a German consumer association challenged Aldi Süd brochures that advertised organic bananas at €1.29 with a crossed-out €1.69 and a “-23%” badge. According to Insight EU Monitoring’s summary, the lowest price in the prior 30 days was €1.29, the same as the “reduced” price, so the real reduction was zero. The Court held that a percentage reduction, or a promotional statement stressing an advantageous price, must be calculated from the lowest price in the 30 days before the reduction, as Herbert Smith Freehills Kramer’s analysis of the judgment explains. Showing the 30-day low somewhere on the page while computing the headline percentage from a higher, more recent price does not comply.
A year later, on 9 October 2025, the Bundesgerichtshof ruled in I ZR 183/24, a case brought by the Wettbewerbszentrale against a grocery discounter. The brochure advertised a coffee product at 4.44 with a small-print 6.99 and “-36%”, while the 30-day low appeared only in a footnote at the bottom of the page. The Federal Court of Justice held that under Section 11 of the German Price Indication Ordinance (PAngV), the 30-day lowest price must be stated in a way that is unambiguous, clearly recognisable and easily legible for the consumer. A footnote does not meet that standard.
German case law is also pushing into marketplaces. BBP Legal reports that the Landgericht München I held on 14 July 2025 that a strike-through price on an Amazon listing counts as a price-reduction announcement if the average shopper perceives it as one, regardless of whether a reduction actually happened. And according to ITMR Legal, the Higher Regional Courts of Düsseldorf and Cologne have reached different conclusions on crossed-out manufacturer RRPs, with an appeal to the Federal Court of Justice permitted, so that question remains open in Germany.
After Aldi Süd and the BGH ruling, the calculation base and the display of the 30-day low are both settled in Germany; the open question is RRP strike-throughs, which makes them the riskiest format to rely on.
Roughly one in three online traders in the EU, and three in four major retailers in the Netherlands, based on the two most recent official checks. Both figures come from regulators looking at live promotions, not from surveys.
The European Commission and the Consumer Protection Cooperation (CPC) network published the results of a coordinated Black Friday and Cyber Monday sweep on 26 March 2026. Of 314 online traders checked, 30% referenced discounts incorrectly. The same sweep found that 34% of traders displayed price comparisons and, of those, six in ten did not clearly explain what the comparison price referred to. Commission Executive Vice-President Henna Virkkunen summed up the enforcement stance: “a great bargain is no excuse to cheat the rules.”
Methodology: A sweep is a simultaneous screening of websites carried out by national enforcement authorities under Commission coordination. This one covered authorities from 23 EU member states, including Germany, Belgium and Greece, plus Iceland and Norway. Ireland’s CCPC, a participant, reports that the traders sold goods including cosmetics, fashion, furniture and electrical products. Results reflect the 2025 Black Friday and Cyber Monday sales period. A sweep flags suspected breaches; national authorities decide on enforcement afterwards.
The Dutch picture is sharper. On 20 November 2025, the ACM reported that misleading price presentations were found at 18 of the 24 major retailers it examined, or 75%. Most problems involved the “was” price, often labelled vaguely as a “regular price” or “recommended retail price” without explaining what it meant.
Methodology: The ACM examined the promotional deals of 24 major retailers across furniture, clothing, DIY and gardening, consumer electronics and cosmetics, both online and in physical stores, over the weeks before its 20 November 2025 publication. The sample was chosen by the regulator ahead of the Black Friday, Sinterklaas and Christmas period and is not a random sample of all Dutch retailers.
There is also evidence that honest reference prices change shopper behaviour. In a pre-registered experiment published in the Journal of Consumer Policy, Barrafrem and Tinghög found that displaying the lower 30-day “Omnibus price” significantly reduced purchase intentions, with a stronger effect for utilitarian products than for hedonic ones. Methodology note: the study used an online sample of 500 UK consumers, chosen because the rule does not apply in the UK; no comparable European field study was found, so treat the effect size as indicative rather than a European benchmark.
Non-compliance is common enough that regulators treat it as a sector-wide problem, which means your promotions will be compared against competitors who are also being watched.
The cost ranges from competitor cease-and-desist claims in Germany to six-figure regulatory fines in the Netherlands and Greece, and the legal ceiling for widespread cross-border cases is at least 4% of turnover. Under the Omnibus Directive, member states must allow maximum fines of at least 4% of annual turnover in the countries concerned for widespread infringements, or €2 million where turnover data is not available, as Talon.One and LegalClarity both summarise.
In the Netherlands, the ACM fined the webshop Koopjedeal €163,000 and furniture retailer Leen Bakker €130,000 for fake discounts, and a Dutch court upheld those fines in November 2025. The ACM’s September 2025 guidelines, summarised by Osborne Clarke, make its position explicit: only the lowest prior price may be crossed out, and it is prohibited to raise a price just before a reduction.
In Greece, the Ministry of Development used a digital tool to screen Black Friday 2024 promotions and fined 14 companies a combined €2.22 million, with individual fines of up to €500,000, according to reports in To Vima and ProtoThema. One fined department store said only one of roughly 30,000 products on its e-shop had been flagged and blamed a technical error, which illustrates how a single SKU can carry a six-figure penalty. Several fined companies said they would challenge the decisions. Inspections have continued in 2026: Athens Times reported in June 2026 that inspectors from the new Independent Authority for Market Control and Consumer Protection carried out on-site checks at 10 central Athens retailers after consumer complaints about unlawful discounts.
In Germany, the administrative fine under the PAngV is capped at €25,000 according to trustyourwebsite.com’s guide, but that is rarely the main risk. Competitors and qualified associations can bring claims under the Act against Unfair Competition (UWG), and a screenshot plus a publicly reconstructable price history is often enough evidence. Both landmark cases above started exactly that way.
Poland is outside tgndata’s default markets but shows where enforcement is heading. In January 2026, UOKiK fined Zalando and Temu a combined sum of roughly €8.5 million over how the 30-day reference price was calculated and displayed, according to Omnia Retail’s summary of the decision.
Fines are only part of the exposure; in Germany your own competitors can enforce the 30-day lowest price rule against you, and in Greece a single mispriced SKU was enough to trigger a €400,000 fine.
Back-to-back campaigns, progressive markdowns, new products, multi-channel pricing and RRP comparisons cause most compliance errors, because each changes which price counts as the reference. These are also the formats that pricing calendars in Q4 lean on hardest.
Back-to-back campaigns. When one discount follows another within 30 days, the earlier promotional price usually becomes the new reference. Osborne Clarke’s summary of the ACM guidelines uses the Dutch holiday sequence of Black Friday, Sinterklaas and Christmas as the example: if the price bounces back to normal between campaigns, the next “was” price is the lower promotional price from the previous campaign. An early Black Week price in November can therefore cap the discount you can claim in December.
Progressive discounts. If a discount deepens step by step (for example 10%, then 20%, then 30%), the reference can remain the price before the first reduction, as Benamic explains. The ACM allows this for up to three months, provided the price drops without interruption. Design these deliberately, as part of your promo architecture, rather than discovering them after the fact.
New products. For products on sale for fewer than 30 days, the ACM accepts a reasonable, clearly stated shorter reference period. Polish guidance, as summarised by Dudkowiak & Putyra, uses the lowest price since the product was first offered.
Multi-channel pricing. Where a seller uses different prices across channels and announces a reduction, the prior price must be indicated for each channel, according to Dudkowiak & Putyra’s summary of Polish guidance. If your marketplace price and your webshop price diverge, as covered in marketplace pricing vs DTC pricing, each needs its own 30-day history.
Targeted and conditional offers. Some formats sit outside Article 6a. Centra notes that discounts aimed at a limited number of consumers, such as individual loyalty vouchers, are not covered, and member states may set different rules for perishable goods. These exemptions are narrow and vary by country, so confirm them locally before relying on them.
The riskiest promotion in Q4 is the one that starts within 30 days of the last one, because the earlier deal quietly becomes the benchmark for the next.
Because you cannot display a 30-day low you never recorded, and most commerce stacks store the current price, not a timestamped history of every price shoppers actually saw. Legal review can check the wording of a banner, but only price data can confirm the number on it.
A compliant reference price needs four things: the product, the channel, the price as displayed to consumers (including any automatic basket discount that counts as a price reduction), and a timestamp for every change. Dynamic pricing makes this harder, not easier. A repricing rule that briefly undercuts a competitor at 03:00 on a Tuesday creates a new 30-day low that your marketing team will not know about when it builds Friday’s “-25%” banner.
The Greek department store case shows the failure mode. A catalogue of about 30,000 products, one technical error, one flagged SKU, one fine. Errors like this usually trace back to the same root causes covered in why bad pricing data wrecks decisions: feed mismatches between the shop front and the pricing engine, variant-level prices that differ from parent-level records, and marketplace listings updated outside the main system.
External monitoring solves the evidence problem from the outside in. A price monitoring platform captures prices as they appear on the live page, with the timestamp, the channel and the stock status, and keeps that record in historical data you can query later. That gives pricing and legal teams an independent record of what was shown, which is harder to dispute than an internal database export.
Treat your 30-day low as a calculated field backed by timestamped evidence, not a number someone looks up the day before a campaign.
Competitor price history lets you see whether a rival’s “-40%” is a real market move or an inflated reference price, which changes whether you should respond at all. With 30% of online traders referencing discounts incorrectly in the Commission’s sweep, a meaningful share of the “deals” your team reacts to each November may not be deals.
Take a practical scenario. A competitor launches a “-35%” badge on a hero SKU that you both sell. Your alerting flags it and the category manager is asked to match. The competitor’s 30-day history shows the product was sold at almost the same price two weeks earlier; the badge is computed from a higher price set for five days in between. The real market price barely moved. Matching the badge would cut your margin to respond to a price that already existed, while the competitor carries the regulatory risk.
This is where competitors’ price history earns its keep. Three uses stand out:
The most useful thing competitor monitoring does in Q4 is stop you from matching discounts that were never real.
For brands, the rule turns the RRP from a marketing anchor into a compliance risk for every retailer that uses it as a strike-through, and that risk reflects back on the brand’s price positioning. A retailer advertising “-40% vs RRP” on your product invites scrutiny and can reset what shoppers think the product is worth.
The ACM’s position, as summarised by BlossomYourContent’s analysis of its guidance, is that a crossed-out advice price can be treated as a prior price under the 30-day rule if the RRP was not actually charged, if it is unclear who set it, or if it creates the impression of a reduction that does not exist. The Munich ruling on Amazon strike-throughs points in the same direction in Germany. Brands that publish RRPs far above real market prices are, in effect, supplying retailers with a reference price that regulators may reject.
For Brand Managers, this adds a new dimension to channel monitoring. Alongside checking whether retailers respect agreed price floors, as covered in MAP monitoring, it is worth tracking how retailers present discounts on your products: which ones use your RRP as a strike-through, how far that RRP sits above the real market price, and whether “was” prices match what the retailer actually charged. EU competition law limits how far brands can dictate resale prices, so treat this as market intelligence and retailer guidance, not enforcement, and involve legal counsel on any policy.
An RRP that no one in the market actually charges is no longer a pricing anchor in the EU; it is a liability for every retailer that crosses it out.
For a Black Friday reduction that starts on Friday 27 November 2026, the 30-day reference window opens on 28 October; for a Black Month that starts on 1 November, it opens on 2 October, nine days from today. Every price you charge inside that window is a candidate reference price.
Earlier campaigns pull the window earlier. In Greece, the 2022 reform that abolished the fixed May and November sales periods lets retailers run promotions at any time, and To Vima reports that Black Friday has stretched into a Black Week or even a Black Month as a result. The same stretching is happening elsewhere, as tgndata covered in Black Friday pricing prep 2026.
| Campaign start (2026) | Campaign | 30-day window opens | What to lock in |
|---|---|---|---|
| Thu 1 October | Early “Black Month” (common in Greece) | Tue 1 September (already open) | Audit September price history now |
| Sun 1 November | Black Month | Fri 2 October | Freeze October test prices on hero SKUs |
| Fri 20 November | Black Week | Wed 21 October | Avoid October flash sales on promoted SKUs |
| Fri 27 November | Black Friday | Wed 28 October | Record the reference price per SKU and channel |
| Mon 30 November | Cyber Monday | Sat 31 October | Check whether Black Friday prices reset it |
| Sat 5 December | Sinterklaas (NL/BE) | Thu 5 November | Black Friday price likely becomes the reference |
Window dates assume the reduction starts on the campaign date and count 30 days back from the day before. Confirm the counting convention with counsel in each market.
The practical conclusion is uncomfortable for promotional calendars: a flash sale in October can quietly shrink the headline discount you can claim in November. The margin-protecting Black Friday strategy tgndata published this week argues for lighter discount bands on hero SKUs; the 30-day rule is one more reason to plan those bands before October pricing decisions are made.
The prices you set in October are not just October prices; they are the evidence base for every discount you advertise until Christmas.
Probably, but not before 2027 at the earliest: the Commission’s 2026 work programme lists the Digital Fairness Act for the fourth quarter of 2026, and it is expected to address unfair personalisation and deceptive pricing practices. The 30-day rule itself is already in force and will not wait for it.
According to the European Parliament’s Legislative Train tracker, the initiative is expected to tackle dark patterns, influencer marketing, addictive design and unfair personalisation practices. Law firm William Fry’s analysis of the consultation found notable support for limiting or banning drip pricing, misleading “starting from” prices and deceptive discounts, alongside concern about personalised pricing aimed at vulnerable groups. Some legal commentators, such as Taylor Wessing, have noted that the rules could affect any business using dynamic pricing or personalisation to influence consumer decisions.
For retailers using dynamic pricing software, the distinction to watch is between market-based repricing (the same price for every shopper, adjusted to competitors and stock) and personalised pricing (different prices for different shoppers based on their data). The first is where most retail price intelligence sits today. The second is where regulatory pressure is building on both sides of the Atlantic.
Build your 30-day price history now; whatever the Digital Fairness Act adds, it will assume you can already prove what you charged and when.
Turn the 30-day rule into a data process owned by pricing, with legal sign-off, rather than a banner check owned by marketing. Here is how that breaks down by role.
Pricing Managers
Ecommerce Managers
Category Managers and Commercial Directors
Brand and Marketplace Managers
The teams that handle the 30-day rule well treat it as one more pricing KPI, measured daily, instead of a legal checklist reviewed the week before the sale.
The 30-day lowest price rule is the EU requirement, in Article 6a of the Price Indication Directive as amended by the Omnibus Directive, that any announced price reduction must show the lowest price the trader applied to that product in at least the 30 days before the reduction. That lowest price is the only valid reference for the discount, so strike-through prices, percentages and “you save” claims must all be calculated from it.
Yes. The Court of Justice of the EU ruled in Case C-330/23 (Aldi Süd) on 26 September 2024 that a percentage reduction or a promotional claim stressing an advantageous price must be calculated from the lowest price in the prior 30 days, not from the most recent, higher price. Showing the 30-day low in small print while computing the percentage from another number does not comply.
Using an RRP as a strike-through price is high risk, because regulators and courts assess whether the shopper perceives it as a price reduction. The Dutch ACM warns that a crossed-out advice price can be treated as a prior price subject to the 30-day rule, and German courts have applied the rule to strike-through prices on Amazon listings, while German appellate courts have differed on crossed-out RRPs. Clearly label any RRP and never let it imply a reduction from your own price.
If a new discount starts within 30 days of an earlier one, the earlier promotional price usually becomes the lowest price and therefore the new reference price. The Dutch ACM’s guidance uses Black Friday, Sinterklaas and Christmas as the example: if the price briefly returns to normal between campaigns, the reference for the next discount is the lower promotional price from the previous one.
Penalties are set nationally, but the Omnibus Directive requires maximum fines for widespread cross-border infringements of at least 4% of annual turnover in the member states concerned, or €2 million where turnover data is unavailable. In practice, the Dutch ACM has fined webshops €130,000 and €163,000, Greece’s Ministry of Development fined 14 companies a combined €2.22 million after Black Friday 2024, and in Germany competitors and associations can bring claims under unfair competition law.
Price monitoring creates a timestamped, per-channel record of the prices shoppers actually saw, which is the evidence needed to prove a 30-day low and to calculate a compliant discount. It also shows competitors’ genuine price histories, so you can spot fake discounts in your market, avoid reacting to inflated reference prices, and benchmark against real selling prices rather than strike-through claims.
Missing an important marketplace?
Send us your request to add it!