List Price: Apply the 30-day rule to each discount
The reference price is the lowest price charged in the 30 days prior to a price reduction.
Any advertisement for a discount must display the original price, and following a September 2024 ruling by the Court of Justice of the European Union, the discount percentage must be calculated based on that price.
A temporary price drop therefore becomes the benchmark for one month. Successive price reductions and perishable products are subject to specific rules. Applying the rule requires a dated price history, organized by product ( product by product ) and by channel.
A four-day price reduction at the beginning of the month means that the discount planned for the end-of-month flyer can no longer be advertised as originally intended.
This is the result of the 30-day rule, which many retailers discover when they're setting up a promotion.
This article explains the rule, how it is calculated based on the 2024 ruling by the Court of Justice of the European Union, its exceptions, and how to manage it throughout the year.
What is the reference price for a discount?
The reference price is the lowest price charged by a seller to all of its customers during the 30 days prior to the application of a discount.
Any advertisement for a discount must display this price, and the discount percentage is calculated based on it.
The rule has been included in Article L.112-1-1 of the Consumer Code since May 28, 2022. It transposes the European “Omnibus” Directive, which was adopted to combat false promotions.
It applies year-round, both in-store and online, and to all forms of advertising: strikethrough prices, percentage discounts, “shock prices,” or discount amounts. It supplements the other price compliance rules that a retailer must follow.
How is a reduction calculated starting in 2024?
On September 26, 2024, the Court of Justice of the European Union ruled on a point that had been the subject of debate.
In the case pitting a consumer association against the Aldi Süd chain, the court ruled that the advertised discount percentage must be calculated based on the lowest price over the past 30 days.
It is therefore no longer sufficient to display this price somewhere on the label while calculating the discount based on the most recent price charged. Both the display and the calculation must be based on the same reference price.
| Period | List Price | Effect on the reference price |
|---|---|---|
| From the 1st to the 20th | 10.00 € | Regular price |
| From the 21st to the 25th | €8.50 | Becomes the lowest price in the last 30 days |
| From the 26th to the 30th | 10.00 € | The reference price remains at €8.50 |
| On the 31st, on sale for €8.00 | €8.00 | Discount to be advertised: approximately -6%, not -20% |
The example illustrates where the risk lies: a temporary drop—even one lasting just a few days—becomes the new benchmark price for a month. A discount announced too soon after this drop then becomes inaccurate.
Special cases provided for by the rule
Successive reductions
When there are several consecutive price reductions during the same promotional period, the reference price remains the price that was in effect before the first reduction.
A progressive markdown can thus display increasing discounts without recalculating the base price at each stage.
This exception applies to a continuous promotion that is advertised as such. It does not cover a series of unrelated promotions separated by periods when the regular price is in effect.
Perishable goods
Perishable products at risk of rapid spoilage are exempt from the 30-day rule. This is what allows for end-of-day discounts on fresh produce, a topic we cover in the section on fresh produce promotions, cannibalization, and markdowns.
A Comparison with Other Sellers
Comparing one's price to that of a competitor, without presenting that comparison as a discount, does not fall within the scope of the rule.
On the other hand, a “suggested” price or a price charged elsewhere that is presented as a strikethrough price gives the impression of a discount and must reflect that discount.
The role of the suggested retail price in pricing policy is discussed in our article on the suggested retail price.
Where Retailers Most Often Go Wrong
The DGCCRF inspected 350 businesses and websites regarding price reductions: one-third of those offering discounts were found to be noncompliant.
(DGCCRF, 2024 survey on consumer information regarding prices and discounts, report published on November 24, 2025)
The violations identified by the DGCCRF are similar: no reference price, replaced by a suggested retail price or a price charged elsewhere; exaggerated or nonexistent discounts; and crossed-out prices displayed permanently.
These aren't always cases of fraud. In a network, some prices come from a reference price calculated manually, based on a single channel, or on historical data that doesn't account for short-term price drops.
Discrepancies between channels and between stores
When the store and the website have different prices, a question arises: Which price from the last 30 days serves as the reference for a discount advertised on a particular channel?
The position adopted must be approved by a legal expert, documented, and applied consistently across the board.
Whatever that position may be, you must be able to document it in the event of an audit. This requires a dated price history, maintained separately for each channel.
Retailers that charge different prices by store or by region face the same challenge at the individual store level. See geopricing and price differences across channels.
Special prices for cardholders
A price available only to members of a loyalty program is not offered to all consumers.
Whether to include it in the reference price is also a matter that must be reviewed by a lawyer and then applied consistently across the board.
Implement the 30-day rule year-round
Our belief: The reference price should not be determined when planning a campaign. It must be available and calculated for each product, each channel, and each day.
This is the only way to know, before approving a promotion, what discount can actually be advertised. And to identify temporary price drops that “eat into” the discount for an upcoming promotional event.
This perspective changes the way we plan a promotional calendar: a price cut decided in October affects what can be announced in November. The case of Black Friday is discussed in “Black Friday: Real and Legitimate Discounts.”
For implementation using a tool, see “Monitoring Discount Offers with a Pricing Tool.” The profitability of these operations depends on measuring the incremental impact of promotions.
Do you want to make your discount ads more reliable?
Our experts will show you how to calculate the reference price for each product every day before setting up your operations.
Let's discuss your benchmark pricesSee also in this feature
FAQ: List Prices and Sale Announcements
This is the lowest price the seller has charged any customer during the 30 days prior to the application of a discount.
It must be displayed with any sale announcement, both in-store and online, and serves as the basis for calculating the discount percentage.
The rule has been included in Article L.112-1-1 of the Consumer Code since May 28, 2022, pursuant to the European “Omnibus” Directive.
Since the European Court of Justice’s ruling on September 26, 2024, the percentage is calculated based on the reference price—that is, the lowest price over the past 30 days.
A product sold for €10, which dropped to €8.50 for a few days and then returned to €10, cannot be advertised as a 20% discount at €8 within the following month: the actual discount, calculated based on €8.50, is approximately 6%.
It applies with one exception: if there are successive price reductions during the same period, the reference price remains the price in effect before the first reduction.
A progressive markdown can thus display increasing discounts without recalculating the base price at each stage.
This exception applies to a continuous promotion that is advertised as such. A series of unrelated promotions, separated by periods when the regular price is in effect, falls under the general rule.
Perishable goods at risk of rapid spoilage are excluded from the 30-day rule.
This is what makes it possible to lower the price of a fresh product at the end of the day or as its expiration date approaches without displaying a reference price. The exception applies to products that are genuinely perishable, not to the entire fresh food section.
Presenting a suggested retail price as a strikethrough price gives the impression of a discount: the ad must therefore comply with the reference price rule.
The DGCCRF regularly identifies advertisements in which the reference price is replaced by a suggested retail price or a price charged elsewhere. It is still possible to compare one’s price to that of a competitor, provided it is not presented as a discount.
A violation may result in a compliance order, an administrative fine, and, if the advertisement is misleading, penalties for deceptive business practices.
During its 2024 investigation, the DGCCRF issued orders or filed reports against 10% of the establishments inspected.
The amount of the penalties depends on the severity of the violation and the applicable regulations: a legal professional should be consulted on a case-by-case basis.
By having the reference price for each product on hand before preparing a transaction, rather than looking it up at the time of the announcement.
This requires a dated price history, stored on a " product by product " basis and on a channel-by-channel basis, which also records short-term declines.
A pricing tool can then indicate the actual discount that can be advertised and flag price reductions that would diminish the discount for an upcoming promotional event.
In the toy industry, Black Friday kicks off the Christmas shopping season, which accounts for more than a third of annual sales. With the 30-day rule, its price becomes the benchmark for nearly all December promotions.
The discount applies only to the toys being compared, not to licensed products or this year's new releases. Baby care—a thoughtful purchase driven by the timing of births—calls for moderate discounts.
In the high-tech sector, Black Friday accounts for a major portion of annual sales and takes place two months after the back-to-school product launches. It is intended to clear out the previous generation of products rather than to sell off the new ones at a discount.
Refurbished products set a ceiling on the price of new items, and some prices are rising due to the cost of components. The advertised discount is always calculated based on the lowest price over the past 30 days.
When it comes to home appliances, Black Friday success depends more on the selection of models than on the size of the discounts. An 8% price reduction may require a 50% increase in sales to maintain the same profit margin.
It's best to act quickly on the models that are actually being compared, maintain the prices of exclusive models, focus on delivery, installation, and trade-ins, and prepare the 30-day policy starting in October.