Quick answer
In the EU, any announced price reduction must show the prior price: the lowest price the trader applied during at least the 30 days before the reduction (Article 6a of Directive 98/6/EC, added by the Omnibus directive). France applies it through Article L112-1-1 of its Consumer Code since 28 May 2022, and the EU Court of Justice ruled in 2024 that the announced percentage must be calculated on that price. Black Friday is no exception.
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Test 3 URLs for freeBlack Friday falls on 27 November 2026. For online stores selling to EU consumers, it is also when fake discounts are easiest to spot: a price raised a few days before the sale, then a strikethrough price displayed against that inflated price. The French consumer protection authority (DGCCRF) says it checks these rules in particular during national events such as the sales and Black Friday. This guide covers the EU rule, how French law applies it, a worked example, the exceptions and a checklist.
What does the 30-day rule say?
Article 6a of Directive 98/6/EC, inserted by the Omnibus directive (EU) 2019/2161, sets the framework for every announcement of a price reduction:
- Any announcement of a price reduction must show the prior price. Strikethrough price, “−20%”, “€15 off”: the format is free, but the reference price must be displayed.
- The prior price is the lowest price applied during at least the 30 days before the reduction.
- Member states may adapt three cases: goods that deteriorate or expire rapidly, products on the market for less than 30 days, and reductions that increase progressively.
In France, Article L112-1-1 of the Consumer Code applies a 30-day period, to the lowest price applied “to all consumers”. According to the DGCCRF, it covers every price reduction announcement, online and in stores. Other EU countries apply the same principle through their own national laws, with their own choices on these options and their own penalties.
The strikethrough price is therefore neither the “usual” price nor the last displayed price: it is the lowest price of the last 30 days. A recent promotion counts too. If every customer could buy the product at a reduced price two weeks ago, in a separate promotion, that reduced price becomes your reference price.
Example: a non-compliant Black Friday strikethrough price
Fictitious prices. Black Friday falls on Friday 27 November 2026, so the 30 days before it run from 28 October to 26 November.
| Period | Displayed price | What it means |
|---|---|---|
| 28 October to 14 November | €89 | Lowest price of the 30 days: this is the reference price. |
| 15 to 26 November | €99 | Increase just before the event. |
| 27 November (Black Friday) | Non-compliant: the strikethrough price is the wrong one. |
The reference price is €89, not €99. The real discount is (89 − 79) ÷ 89, about 11%, not 20%. Two displays would have been correct:
- €89 struck through, €79, i.e. −11%: the announcement describes the real reduction.
- €89 struck through, €71.20, i.e. −20%: if you want to announce −20%, this is the price to charge.
Which price should the discount percentage be based on?
Showing the lowest price of the last 30 days is not enough. In a judgment of 26 September 2024 (case C-330/23, Aldi Süd), the Court of Justice of the European Union ruled that the announced reduction, whether a percentage or a statement highlighting how advantageous the offer is, must be calculated on that prior price.
In that case, a leaflet announced −23% on bananas at €1.29, calculated on the price applied just before the offer (€1.69), while the lowest price of the previous 30 days, shown below the announcement, was already €1.29. For the Court, merely mentioning the lowest price without using it as the basis of the calculation would allow traders to raise a price just before a promotion and display a fake discount.
What are the exceptions to the 30-day rule in France?
| Situation | What French law provides |
|---|---|
| Successive reductions during a set period (for example markdowns during the official sales) | The reference price remains the price applied before the first reduction. |
| Perishable goods at risk of rapid deterioration | The prior price rule does not apply. |
| Comparison with other traders’ prices (manufacturer’s recommended price, price found elsewhere) | This is not a reduction within the meaning of Article L112-1-1. According to the DGCCRF, consumers must be clearly told that it is a comparison and what the comparison price is. |
How to calculate stacked markdowns is covered in our article on successive discounts. Price comparisons remain regulated: Article L121-2 of the French Consumer Code explicitly lists price comparisons among the elements on which a commercial practice can be misleading.
What are the penalties for a fake strikethrough price in France?
An inaccurate price reduction can be a misleading commercial practice: Article L121-2 of the Consumer Code refers to “the promotional nature of the price, in particular price reductions within the meaning of I of Article L. 112-1-1”. Article L132-2 provides up to:
- 2 years’ imprisonment and a €300,000 fine;
- a fine increased, in proportion to the benefits gained, to 10% of average annual turnover or to 50% of the expenses incurred for the advertising or practice;
- 5 years’ imprisonment and a €750,000 fine when the offence is committed online or through a digital medium.
These are statutory maximums, not automatic amounts. In other EU countries, penalties are set by each member state (Article 8 of Directive 98/6/EC). An event such as Black Friday concentrates price reduction announcements over a few days, and it is precisely one of the periods the DGCCRF says it monitors.
How should you check your strikethrough prices before Black Friday?
- List the products on promotion and the exact start date of the event.
- Retrieve your price history for the previous 30 days: export from your CMS, change log or dated records. Keep it, as it documents your reference price.
- Take the lowest price applied to all customers during the period, previous promotions included.
- Calculate the discount on that price, round it down and check that the displayed strikethrough price is that price.
- Check your banners and emails: the percentages they highlight must follow the same calculation as your product pages.
- Check your floor prices: a deep discount must not take you below your effective purchase price, which is prohibited in France except in specific cases (see our article on selling below cost in France).
How can you tell whether a competitor’s promotion is real?
The same rule applies to your competitors. To know whether a competitor’s “−30%” is a genuine reduction or a price raised just before the event, you need its price over the previous 30 days. With a history of price checks, you can see whether the displayed strikethrough price matches the price actually applied before the promotion, and decide whether to react based on the real price.
Competiprice automatically checks the prices of the competitor URLs you track and keeps them in a history: 30 days from the Standard plan, 90 days on Comfort and unlimited on Premium (7 days on the free Discovery plan). To cover the 30 days before Black Friday, start tracking by 28 October 2026 at the latest. One check per day gives a good indication, not proof: a price can change between two checks.
To be notified when a competitor changes its price, set up competitor price alerts; our 7 alert scenarios help you choose the right triggers.
No account needed: check that your competitors’ prices are detected, then start tracking.
Frequently asked questions about strikethrough prices
Must a strikethrough price be the lowest price of the last 30 days?
In the EU, yes. The prior price shown in a price reduction announcement is the lowest price applied by the trader during at least the 30 days before the reduction (Article 6a of Directive 98/6/EC). In France, Article L112-1-1 of the Consumer Code has applied this rule since 28 May 2022.
Does the 30-day rule apply to Black Friday?
Yes. Black Friday is a commercial event like any other: any announced reduction must start from the lowest price of the previous 30 days. The French DGCCRF names the sales and Black Friday among the events it checks in particular.
How do you calculate a discount percentage?
On the reference price, meaning the lowest price of the 30 days: (reference price − reduced price) ÷ reference price. The Court of Justice of the European Union confirmed this on 26 September 2024 (case C-330/23).
Can you strike through the manufacturer’s recommended price?
In France, this is a comparison with another trader’s price, not a reduction within the meaning of Article L112-1-1. Consumers must be clearly told that it is a comparison and what the comparison price is (recommended price, price found elsewhere…).
What are the penalties for a fake strikethrough price in France?
A misleading price reduction is a misleading commercial practice: up to 2 years’ imprisonment and a €300,000 fine, increased to 5 years and €750,000 when the offence is committed online (Article L132-2 of the French Consumer Code).
Sources consulted on 30 September 2026: Directive 98/6/EC, consolidated text, Articles 6a and 8; French Consumer Code, Article L112-1-1, Article L121-2 and Article L132-2 (in French); DGCCRF, price reduction announcements (in French); French Ministry for the Economy, Legal Affairs Directorate, summary of the CJEU judgment of 26 September 2024 (in French). This article is general information, not legal advice.