Black Friday on PrestaShop: how to show the Omnibus Directive lowest price from the last 30 days

If you're planning to announce Black Friday discounts in your PrestaShop store, the strikethrough price has to be the lowest one you charged for that product in the previous 30 days. Your last price won't do, and neither will a “reference” price picked by eye. In short: you need a history of each product's real price that records itself. And it has to be running before you touch any price for the campaign.

The problem: you don't get to choose the “before” price of your sale

Directive (EU) 2019/2161, known as the Omnibus Directive, introduced article 6a. Under this article, any announcement of a price reduction must state the prior price the trader applied for a set period before the reduction. In Spain, for example, article 20 of the Retail Trade Act defines the prior price as the lowest price applied to identical products in the preceding thirty days.

For an online store, that means your Black Friday strikethrough price comes from what you actually charged during those 30 days. If you ran another promotion in that window, even a weekend one, that discounted price counts. The European Commission's guidance on article 6a makes it clear: ignoring the prices of an earlier promotion within those thirty days breaches the rule.

And it happens more often than you'd think. A European Commission report from June 2024 found that 23% of the price reduction announcements it analyzed failed to comply with article 6a.

How to calculate the correct reference price

The Commission explains it with an example in its guidance. Say you announce “50% off” and the lowest price in the previous thirty days was EUR 100. You must state EUR 100 as the prior price and calculate the 50% from that figure, even though the product's last selling price was EUR 160.

The Court of Justice of the EU confirmed this on September 26, 2024, answering a question referred by the Landgericht Düsseldorf. It isn't enough to mention the prior price somewhere in the ad: the discount percentage has to be calculated from it. Baker McKenzie sums it up well.

What you do in PrestaShop and what's missing

In PrestaShop, you set up a sale by editing the product or creating a specific price. What the rule adds is that the prior price you state must be the lowest final price you displayed in the previous 30 days. If that figure comes from a spreadsheet or from memory, you're exposed on two fronts. You might miss an earlier promotion. Or the “prior price” you type in might be higher than the real one, which is exactly the misleading practice the rule penalizes.

How we solve it with Omnibus Price

For exactly this, we have Omnibus Price, our module that keeps a real price history and shows the lowest price of the last 30 days on discounted products. We designed it so the reference price comes from what your store actually displayed. No “prior price” entered by hand. It's compatible with your PrestaShop and works without a cron and without customer data.

Step by step: reach Black Friday with your price history running

Order matters here, because the history starts building the day you install the module. We recommend following these steps:

1. Install the module before you touch prices. It works with hooks only, no overrides, and installs and uninstalls cleanly. From then on, it records the final displayed price of every product.
2. Keep your usual prices until the campaign. Don't raise them in the weeks before. An inflated price doesn't qualify as a prior price and, on top of that, it stays in the history.
3. Adjust what customers will see. Review the notice texts in each language with the rich-text editor. Also decide whether to show the “lowest price!” badge and the recommended-price line.
4. Schedule your sales as usual. Edit the product or create the specific price. The module captures the change in real time, and the product being viewed is refreshed on the fly.
5. Check the compliance dashboard before going live. Look at the status of each discounted product and the global score. Fix any product flagged as Warning, Not compliant or Dark pattern.

Frequently asked questions