Raised the price before a sale? How the Omnibus rule treats it

A common way to make a sale look bigger used to be simple: raise the regular price a little before the sale, then discount from the higher price. In the EU, the Omnibus price rule was written to stop exactly this.

This article walks through what happens to a discount when the price went up shortly before it, with step-by-step examples. If you need the full picture of the rule first, read the 30-day lowest price rule for WooCommerce.

The rule in one paragraph

Under Article 6a of Directive 98/6/EC, every announcement of a price reduction to consumers must show the prior price: the lowest price the shop applied in a period of at least 30 days before the reduction. Since the Court of Justice’s Aldi Süd judgment of 26 September 2024 (case C-330/23), a percentage or other claim about the saving must also be calculated from that prior price.

The key word is lowest. A higher price in the 30 days before a sale does not replace a lower one. The lowest price of the window is the reference, whatever came after it.

Example 1: a price increase three weeks before a sale

Example prices. A shop sells a desk lamp.

Period	Price
Until 30 September	€80.00
From 1 October (price increase)	€100.00
From 20 October (sale)	€80.00, advertised as “-20%”

The sale starts on 20 October, so the 30-day window is 20 September to 19 October. The lamp cost €80.00 for the first 11 days of that window and €100.00 for the remaining 19 days.

• Prior price: €80.00, the lowest price in the window.
• Sale price: €80.00.
• Genuine reduction: none.

The shop cannot present this as a reduction. The Court said in Aldi Süd that the price presented as reduced cannot be the same as the prior price or higher than it. Showing “€100.00 €80.00, -20%” would be a reduction that did not happen.

The same lamp with a deeper sale price

Suppose the shop sets the sale price at €72.00 instead.

	WooCommerce default display	Under Article 6a and Aldi Süd
Crossed-out price	€100.00 (regular price field)	€80.00 (lowest in 30 days)
Sale price	€72.00	€72.00
Percentage badge	-28%	-10%

The reduction is real, but it is 10%, not 28%. The badge and the crossed-out price must both use €80.00.

A small detail: when a percentage is not a whole number, rounding it down avoids overstating the saving. For example, €80.00 to €70.00 is 12.5%, so “-12%” is the safe way to show it.

Example 2: the increase was long enough ago

Example prices. Same lamp, but the price went up from €80.00 to €100.00 on 10 September, and the sale at €72.00 starts on 20 October.

The window is again 20 September to 19 October. This time the lamp cost €100.00 for the whole window, so the prior price is €100.00, and “-28%” is calculated correctly under Article 6a.

Two things to keep in mind:

• Thirty days is the minimum period in the directive. Some shops choose a longer look-back to be safe. Showing a lower prior price than the law requires is always allowed; showing a higher one is not.
• Article 6a is not the only rule. The Commission’s guidance points out that price reduction practices can also be assessed under the Unfair Commercial Practices Directive 2005/29/EC. A “regular” price that was never really charged, or set only to create a reference, can be misleading under that directive even if the 30-day arithmetic works out.

The Dutch authority ACM gave an example of the second point in its June 2024 decision against five online shops (€621,000 in fines in total). In one case, a shop raised a product’s “was” price from €149.99 to €199.99 a day after listing it, then offered it at €99.99. ACM found that the €199.99 price had never been used as a selling price in the period it examined.

Example 3: two sales close together

Example prices. A jacket normally costs €100.00.

Period	Price
1 to 7 October (first sale)	€70.00
8 to 24 October	€100.00
From 25 October (second sale)	€75.00

The window for the second sale is 25 September to 24 October. It includes the first sale, so the prior price is €70.00. The second sale price of €75.00 is higher than that, so the second sale is not a reduction at all under Article 6a.

This catches many shops in autumn: a mid-October promotion can make a Black Friday price look like no discount, because the earlier sale price is still inside the 30-day window. The Commission’s guidance is explicit that a previous reduced price in the period counts.

Example 4: stepped discounts in one campaign

Example prices. A sofa costs €1,000.00 all of October. A clearance campaign starts on 1 November at €900.00 (-10%) and goes to €800.00 (-20%) on 8 November.

What the reference is for the second step depends on the country, because Article 6a(5) is an option for member states:

	Reference for the €800.00 step	Badge
Germany (§ 11(2) PAngV): option used	€1,000.00, the price before the first step	-20%
Poland: option not used	€900.00, the lowest price in the 30 days before the second step	-11%

Where the option exists, it covers a reduction that increases without interruption in one campaign. The Commission’s guidance reads the exception narrowly. If the price goes back up between the steps, even briefly, the campaign is interrupted and the general rule applies again.

Where WooCommerce gets it wrong by default

WooCommerce shows the regular price crossed out next to the sale price. Many themes also add a percentage badge calculated from those two fields.

This is only correct if the regular price is also the lowest price of the 30 days before the sale. In each example above, that is not the case:

• In example 1, WooCommerce would show €100.00 crossed out after a recent increase.
• In example 3, it would show €100.00 crossed out and ignore the first sale.
• In example 4 (Poland), it would show -20% where -11% is correct.

WooCommerce does not store a price history, so it has no way to know. You either keep the history yourself or use a plugin that records it. The main guide lists what to look for.

How to plan price changes around a sale

1. Look at the last 30 days before planning the discount. Find the lowest price in the window, including short promotions and flash sales.
2. If you need a price increase, make it a genuine one. Raise the price for real business reasons and sell at it. Do not plan it as the first half of a sale.
3. Space your sales. If you run a promotion in October, expect it to be the reference for a sale that starts within 30 days of it.
4. For stepped campaigns, check the country. Keep the steps uninterrupted where the option exists, and calculate each step separately where it does not.
5. Never show a reduction that is zero or negative. If the sale price is not below the prior price, remove the crossed-out price, the badge and any “sale” label for that product.
6. Keep the history. If an authority asks, you should be able to show how each reduction was calculated.

What enforcement looks like

Authorities are checking precisely these patterns.

• Netherlands, June 2024. ACM fined five online shops a total of €621,000 for fake discounts. In some cases, ACM said, there was no discount at all and the price had actually gone up.
• Poland, January 2026. UOKiK fined Zalando about PLN 30.9 million and Temu about PLN 5.9 million. The practices described include changing the reference price while the selling price stayed the same, and calculating reductions from an initial or regular price rather than the 30-day lowest price. Both decisions are not yet final.

FAQ

Can I just raise the price and not call it a sale later?

Yes. Article 6a is about announcements of a price reduction. Price increases themselves are not restricted by it, and a later price change that is not announced as a reduction does not need a prior price. The problem only starts when you present the lower price as a discount.

Does the 30-day window include the day the sale starts?

The directive says “prior to the application of the price reduction”. In the examples we use the 30 calendar days before the first day of the sale. If a sale starts at a specific time, the safest approach is to treat the window as ending at that moment.

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