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Solution - Price-history and discount-claim verification
Check every "was" price against what was actually charged
RivalSweeper records product prices every day and keeps a dated history for each product page. We use that record to test "was/now" and "% off" claims, run the EU 30-day prior-price check, and hand you a dated, reproducible record of what was charged and when.
What the rules ask for
A discount claim is only as good as the reference price behind it. On both sides of the Atlantic, the reference price has to match what the store really charged.
The prior price is the lowest price in the last 30 days
Article 6a of the Price Indication Directive (98/6/EC), added by the Omnibus Directive (EU) 2019/2161 and applicable since 28 May 2022, says any announced price reduction must show the prior price. The prior price is the lowest price the trader applied in a period of at least 30 days before the reduction.
Member States may set different rules for a few cases, such as goods that spoil quickly, products on sale for less than 30 days, and reductions that grow step by step.
The percentage has to be calculated from that 30-day low
In Aldi Süd (C-330/23, judgment of 26 September 2024), the Court held that a reduction announced as a percentage, or through a promotional line stressing a low price, must be calculated from the lowest price applied in the 30 days before the reduction, not from the last price charged before the offer.
The Court's stated aim: stop traders from raising a price shortly before a sale so the discount looks bigger than it is.
A former price has to be a real, recent selling price
The FTC Guides Against Deceptive Pricing (16 CFR Part 233) treat a former-price comparison as fair when the item was openly and actively offered at that price, in good faith, for a reasonably substantial period in the recent, regular course of business.
Several states add their own rules. California Business and Professions Code section 17501, for example, ties an advertised former price to the prevailing market price in the three months before the ad, unless the ad states when that price applied.
Sources for each rule are listed in References below.
What we check
Four checks, all run on the same dated record. You get the result and the observations behind it.
Dated price history per product page
Each daily observation is stored with its date, the product URL it came from, the market and the currency. That is the record every other check reads from.
"Was/now" and "% off" claims
We compare the reference price shown in the claim with the prices actually recorded, and recompute the stated percentage from the recorded figures.
EU 30-day prior-price check
We find the lowest recorded price in the 30 days before the reduction started, then compare it with the reference price and with the advertised percentage.
US former-price context
We show how long and how recently the reference price was actually charged, so the claim can be read against the FTC test and state look-back rules.
Who it is for
In-house ecommerce, pricing and compliance teams
- Check your own promotions before they go live, and keep a dated record once they do.
- Review how competitors in your markets communicate discounts, from their public product pages.
- Give compliance a record they can re-run instead of a screenshot folder.
Legal and consumer-protection professionals
- Get a dated price-history record for the products and period in question.
- See each claim next to the prices recorded on the days before and after it.
- Receive the method notes with the data, so the record can be reproduced and challenged on its merits.
Why the record holds up
A price history is only useful as evidence if it does not invent price moves. These guards are part of how RivalSweeper records prices for every customer, not something added for audits.
Like-for-like only
A change counts as a price move only when the source, market and currency all match. A different storefront or currency is never read as a price change.
Implausible jumps are not moves
A jump of more than 5x between observations is not treated as a price move, so one bad reading cannot create a fake discount or a fake increase.
Every figure traces back
Each number in the report points to a dated observation and the product URL it came from, so anyone can follow the working.
History starts when tracking starts
For stores we already monitor, the record goes back to when we started tracking them. For a new store, it starts the day we add it. We say so in the report rather than fill gaps.
What is in the evidence pack
Each audit comes as an evidence pack. This is the structure of what you receive for each product checked.
| Section | What it shows |
|---|---|
| Product and source | Product page URL, store, market and currency. |
| Daily price record | Every recorded price with its observation date, for the period you ask about. |
| The claim | Reference ("was") price, current price and any stated percentage, from the page or from the material you send us. |
| 30-day lowest prior price | The lowest recorded price in the 30 days before the reduction, and the date it applied. |
| Recomputed discount | The discount calculated from the recorded prices, next to the discount as stated. |
| Method and gaps | How the checks were run, plus any days without an observation, listed as gaps. |
How it works
Tell us what to check
Send the stores, product URLs or campaigns, the markets, and the claims you want tested.
We pull the record
We use the price history we already hold, or start recording if the store is new to us.
We run the checks
30-day low, reference price versus recorded prices, recomputed percentage, and how long the reference price was really charged.
You get the evidence pack
Per-product timelines, each claim with its result, and the method notes. Delivered as an audit report.
Pricing that fits what you need checked
Pricing is tailored to what you need checked. Tell us the stores, products and period, and we will scope it together.
- A short, no-obligation call to understand what you need
- We explain what is possible, and what is not, before anything is agreed
- Your questions and the stores you name stay confidential
Frequently asked questions
What is the EU 30-day lowest price rule?
Article 6a of the Price Indication Directive (98/6/EC), added by the Omnibus Directive (EU) 2019/2161, requires any announced price reduction to show the prior price. The prior price is the lowest price the trader applied in a period of at least 30 days before the reduction. It has applied since 28 May 2022, with some room for Member States to set different rules for specific cases.
Does the 30-day rule also cover percentage discounts?
Yes. In Aldi Süd (C-330/23, 26 September 2024), the Court of Justice of the EU held that a reduction announced as a percentage, or through a promotional statement stressing an advantageous price, must be calculated from the lowest price applied in the 30 days before the reduction.
Can you check a competitor's discounts, or only ours?
Both. We record the prices shown on public product pages, so we can check your own promotions and the discount claims of other stores in your markets.
How far back does the price history go?
For stores we already monitor, back to when we started tracking them. For a store we have not tracked before, the record starts the day we add it, so a 30-day check needs at least 30 days of recording before the reduction you want tested.
Is this legal advice?
No. RivalSweeper is not a law firm. We supply the price record and the checks. Whether a claim breaks a rule in a given country is a question for your legal counsel.
Can the record be used as evidence?
We provide a dated, reproducible record with the method behind it. Whether and how it is used in a complaint, investigation or dispute is for your counsel to decide; we do not promise admissibility in any court.
How much does an audit cost?
Pricing is tailored to what you need checked. Tell us the stores, products and period, and we will scope it together. The first call is free and carries no obligation: we explain what is possible before anything is agreed, and the conversation stays confidential.
How do I order an audit?
Book a call through our calendar or contact us. We scope it with you: which stores, which products, which period and which markets.
Public cases that show what is at stake
Public rulings and regulator decisions on reference prices, listed for context. Each line restates the outcome in the linked source at the time it was published. It says nothing about any company's current practices.
Aldi Süd (C-330/23)
A reduction announced as a percentage or as a price highlight must be calculated from the lowest price applied in the 30 days before the reduction.
CJEU press release No 152/24, 26 September 2024Wettbewerbszentrale v. a food discounter (I ZR 183/24)
Advertising a price reduction is unlawful if the lowest total price of the 30 days before the reduction is not stated in an unmistakable, clearly recognizable and legible way.
BGH press release No 184/2025, 9 October 2025Fines on five online stores for fake discounts
Fines totalling EUR 621,000 on five online stores whose discounts were not based on the lowest price offered in the 30 days before the discount.
ACM press release, 11 June 2024Decisions concerning Zalando SE and Whaleco Technology Limited (Temu)
Fines of PLN 30,945,000 and PLN 5,910,900 over how the lowest price of the 30 days before a reduction was shown. The decisions are not final and can be appealed in court.
UOKiK press release, 14 January 2026Tannico s.r.l. (PS12820)
Fine of EUR 150,000 for marking products as on sale at prices equal to or above the lowest price applied in the previous 30 days.
AGCM press release, 17 November 2025Hinojos v. Kohl's Corp. (No. 11-55793)
A shopper who buys on the basis of a false former price, and would not have bought otherwise, has standing to sue under California's false advertising and unfair competition laws.
Ninth Circuit opinion, filed 21 May 2013People v. Overstock.com, Inc. (No. A141613)
Affirmed a judgment imposing USD 6,828,000 in civil penalties and an injunction over its reference-price advertising, including "compare at" prices.
Court of Appeal opinion, 2 June 2017Spann v. J. C. Penney Corp.
Final approval of a class settlement over sale-price advertising, for which the company reported a USD 50 million reserve.
J. C. Penney Form 10-Q, quarter ended 29 October 2016 (final approval 30 September 2016)References
Rules and rulings
- Directive 98/6/EC on consumer protection in the indication of the prices of products offered to consumers (Price Indication Directive), Article 6aEUR-Lex
- Directive (EU) 2019/2161 (Omnibus Directive), which inserted Article 6aEUR-Lex
- Case C-330/23, Aldi Süd, judgment of 26 September 2024Court of Justice of the EU (CURIA)
- Press release No 152/24: a price reduction announced in an advertisement must be calculated on the basis of the lowest price in the last 30 daysCourt of Justice of the EU
- 16 CFR Part 233, Guides Against Deceptive PricingeCFR
- California Business and Professions Code section 17501 (former price advertising)California Legislative Information
Cases and enforcement
- Aldi Süd (C-330/23)Court of Justice of the EU. CJEU press release No 152/24, 26 September 2024
- Wettbewerbszentrale v. a food discounter (I ZR 183/24)Federal Court of Justice of Germany (BGH). BGH press release No 184/2025, 9 October 2025
- Fines on five online stores for fake discountsNetherlands Authority for Consumers and Markets (ACM). ACM press release, 11 June 2024
- Decisions concerning Zalando SE and Whaleco Technology Limited (Temu)Polish Office of Competition and Consumer Protection (UOKiK). UOKiK press release, 14 January 2026
- Tannico s.r.l. (PS12820)Italian Competition Authority (AGCM). AGCM press release, 17 November 2025
- Hinojos v. Kohl's Corp. (No. 11-55793)US Court of Appeals for the Ninth Circuit. Ninth Circuit opinion, filed 21 May 2013
- People v. Overstock.com, Inc. (No. A141613)California Court of Appeal, First District. Court of Appeal opinion, 2 June 2017
- Spann v. J. C. Penney Corp.US District Court, Central District of California. J. C. Penney Form 10-Q, quarter ended 29 October 2016 (final approval 30 September 2016)
Not legal advice. RivalSweeper is not a law firm; this page summarizes public sources and describes a data service. Ask your counsel how the rules apply to you.
Need a dated record of what was really charged?
Tell us the stores, products and claims. We will scope the audit with you on a short, no-obligation call, and explain what is possible before anything is agreed.