In 2026, Black Friday falls on 27 November and Cyber Monday on 30 November. For many shops these are the busiest days of the year, and the days when competitors and consumer associations look most closely at strike-through prices. Since the CJEU ruling C-330/23, every advertised discount has to be based on the lowest price of the 30 days before. Here is what that means for your Black Friday planning.
Which prices count for Black Friday
What counts is the lowest price you charged during the 30 days before the reduction started (§ 11(1) PAngV in Germany, § 9a(1) PrAG in Austria). The CJEU made clear in 2024 that not only the notice, but the discount itself, meaning the strike-through price and the percentage, is calculated from that price.
| Sale starts | These prices count |
|---|---|
| Black Friday, 27 November | 28 October to 26 November |
| Black Week from Monday, 23 November | 24 October to 22 November |
| Cyber Monday, 30 November (separate sale) | 31 October to 29 November |
It also means: raising the regular price in November gains you nothing. The lower price from the weeks before remains the reference.
Pitfall 1: Halloween and Singles’ Day
Halloween (31 October) and Singles’ Day (11 November) fall right inside the window. Any sale on those days lowers the reference price for Black Friday.
| Price | |
|---|---|
| Regular price | €120.00 |
| Singles’ Day, 11 November | €99.00 |
| From 12 November again | €120.00 |
| Black Friday | €89.00 |
On Black Friday, only €99.00 may be struck through, and the discount is about −10 %. Advertising €120.00 and “−26 %” would be exactly what the CJEU ruled out. If you want to show big Black Friday discounts, skip interim sales on the same products in November.
Pitfall 2: Cyber Monday after a break
Many shops end Black Friday prices over the weekend and start a new sale on Monday. What matters is whether the price goes back up in between.
| Price at the weekend | Reference on Cyber Monday | Discount at €70.00 | |
|---|---|---|---|
| Break: back to €100.00 on Sunday | €100.00 | €80.00 (Black Friday price) | about −12 % |
| Continuous: €80.00, then €70.00 on Monday | €80.00 | €100.00 (price before the first step) | −30 % |
If a reduction is deepened step by step without interruption, the price before the first step stays the reference (§ 11(2) PAngV, § 9a(1) second sentence PrAG). After a break, a new reduction starts, and the Black Friday price becomes the lowest price. So plan Black Week as one continuous sale if you want to go deeper at the end.
Pitfall 3: Christmas and the end of the year
The Black Friday price stays in the window for 30 days. An example: a product costs €99.00, €79.00 from 27 to 30 November, then €99.00 again.
- A Christmas sale on 14 December at €89.00 is above the Black Friday price. It may not be advertised as a reduction, not even as “instead of €99.00”.
- Only for sales starting on or after 31 December does the Black Friday price drop out of the window, provided you were not cheaper again in December.
In Austria, this also affects the shopping day on 8 December: a sale on that day is measured against the Black Friday price.
Coupon codes and “20 % off everything”
- Coupon codes offered to everyone, such as “BLACK20 for everyone”, are not individual reductions. Whether they count as a price reduction is not settled. It is safer to treat them as one: the coupon price then counts as the lowest price for the 30 days after.
- Store-wide discounts like “20 % off everything” refer, for each product, to that product’s own lowest price. If a product was reduced recently, it may not be 20 % cheaper than that price at all.
- “Up to −50 %” should only be advertised if products in the sale actually reach that discount, calculated from the lowest price.
Advertising outside the shop
Newsletters, Instagram, Google Shopping and leaflets often name the same discounts as the shop. The same rule applies to them. The simplest approach is to calculate the numbers in one place, the shop, and take feeds and newsletters from there.
Timeline to Black Friday
| When | What |
|---|---|
| By 27 October | Fix regular prices. From 28 October, every price you charge counts. |
| November | No interim sales on Black Friday products, no price increases. |
| Week before Black Friday | Check strike-through prices, percentage badges, feeds and newsletter copy against the lowest price. |
| Black Friday to Cyber Monday | Deepen discounts only without interruption, keep the price history. |
| December | Measure Christmas sales against the Black Friday price. |
Checklist
- The reference for each sale product is the lowest price of the 30 days before the sale starts.
- Strike-through price and percentage are calculated from that lowest price.
- The lowest price is shown as a notice close to the price.
- Products without a real discount are not shown as a sale.
- Cyber Monday follows Black Friday without a price break, or calculates from the Black Friday price.
- Newsletters, social media and feeds use the same numbers as the shop.
- The price history is kept as evidence.
How to calculate the lowest price in special cases is shown in Calculating the lowest price of 30 days. The Austrian specifics are in § 9a of the Price Marking Act.
How Strikewise helps on Black Friday
Strikewise records every price change in your WooCommerce shop and calculates exactly by these rules: the window before the sale starts, breaks between sales and stepwise discounts. The strike-through price automatically becomes the lowest price of 30 days, sham discounts are not shown as a sale, and coupon codes offered to everyone can be marked as a public campaign. All of this is free.
The earlier you install it, the more complete the price history is for Black Friday. If an earlier price is missing, you can enter it in the product. With Premium, the sale planner checks your Black Friday discounts before they go live.