01
The offer
A price reduction compares two prices: the current price and the previous one.
PRICE MONITORING
A saving is proved by the price history, not by the label.
In adverts, in online shops and on days such as Black Friday.
01 / 08The offer
A customer sees 50% off
A handbag at £198, with the earlier price crossed out: £398. They assume they are saving £200.
02 / 08The advert
The reduction starts in the advert
The advert promises 50% off and gives a “was” price: £398. A price statement in an advert must not mislead. The question is when the handbag actually cost that much.
03 / 08The online shop
The crossed-out price lasted one week
The shop raised the price to £398 for seven days and then crossed it out. For the other 23 days of the month the same handbag cost £210.
04 / 08The rule
A “was” price must be the genuine usual selling price
Great Britain has no fixed 30-day rule: the law treats false or misleading information, or a misleading overall presentation, as a misleading action (Digital Markets, Competition and Consumers Act 2024, section 226). The advertising regulator looks at how long the higher price was charged and expects advertisers to provide at least three months of pricing history. Here £398 was charged for seven days: the usual price was £210.
05 / 08Sales events
Up first, then down for Black Friday
Raising the price shortly before Black Friday does not make it the usual price. In 2026 the Advertising Standards Authority ruled that a Black Friday “was” price charged for only 21 days was misleading.
06 / 08The imbalance
Shops that do not inflate prices compete at a disadvantage
The “−50%” takes the clicks from the shop that keeps its price all month, even though the real difference is a few pounds.
07 / 08Monitoring
We record the price every day
We record the price of every product we monitor, with a screenshot, date, time and URL. When the offer arrives, the history already exists.
08 / 08The report
A history anyone can check
The report serves the shopper who doubts an offer, the small retailer who wants to audit a larger rival and the company monitoring rivals that discount off inflated prices. Where there are adverts, we submit the case file to the advertising platform; you or your adviser can report it to Trading Standards through Citizens Advice, or complain to the Advertising Standards Authority.
A saving is proved by the price history. Not by the label.
Description of each scene
- A customer sees 50% off. A product page in an online shop: “Structured handbag”, with the price “£398” crossed out, the price “£198” and the label “−50%”. On the right, under the heading “What the customer assumes”, a large “−50%” and the label “Saving: £200”.
- The reduction starts in the advert. “handbag deals” is typed into the search engine. Two adverts appear: “Handbag −50%”, with “Black Friday · Was £398 · Now £198”, which is outlined in red, and “Structured handbag · £219”, with “The same price all month”. On the right, a card “What the advert says” with “Was £398” and “Now £198 · −50%”, and below it the question “When did it cost £398?”.
- The crossed-out price lasted one week. The product page, with a red circle pulsing over the crossed-out price. On the right, a chart “Price over the last 30 days”: the price holds at £210, rises to £398 and drops to £198. Below it, two labels: “£398 for only 7 days” and “£210 for the other 23 days”.
- A “was” price must be the genuine usual selling price. The price chart, enlarged, with a band “Previous 30 days” and a dashed line at “Usual price: £210”. On the right, a card with three rows: “‘Was’ price shown”, £398, crossed out and with a cross; “Usual selling price”, £210, with a tick; and “Real saving”, 6%, with a tick.
- Up first, then down for Black Friday. A four-week calendar. The first day shows £210. Seven days before Black Friday the cells turn red and “£398” appears with an upward arrow. The Friday of the last week is highlighted with “£198” and the label “Black Friday · −50%”. On the right, three notes: “Goes up 7 days before”, “‘−50%’ on Black Friday” and “£12 less than a month ago”.
- Shops that do not inflate prices compete at a disadvantage. A cursor clicks on the advert “Handbag −50%” and three basket icons appear; the other advert fades. A set of scales tips: “‘−50%’ on the label” weighs more than “Real price”.
- We record the price every day. The VigiaLabs lighthouse sweeps the chart and a dot appears on the price line for each capture. A case file records four items: “Price recorded every day”, “Advertised: was £398”, “Usual price (30 days): £210” and “Real saving: 6%”, alongside “Screenshot · date · time · URL”.
- A history anyone can check. Three paths lead from the case file to “Consumers”, “Small retailers” and “Large companies”. “Price history report” appears, with “Daily price record” and “Alert when the price changes”. On the product page, the crossed-out price becomes £210 and the label “−6%”.
IN SHORT
The crossed-out price lasted one week
The shop raised the price to £398 for seven days and then crossed it out. For the other 23 days of the month the same handbag cost £210.
02
The advert
The earlier price also appears in adverts, crossed out or as a percentage.
03
The online shop
Some shops raise the price for a few days so they can cross it out.
04
The rule
A “was” price must be the genuine usual selling price.
05
Sales events
Black Friday is no exception: the same test applies.
06
Monitoring
VigiaLabs records the price every day, so the history exists before the offer does.
OUR APPROACH
Evidence before assumptions.
What we examine
- Defined searches and locations
- Observed messages and offers
- Ad and destination history
What you gain
Competitive context to review positioning and support recommendations with examples.
- 01
We record the price every day
We record the price of every product we monitor, with a screenshot, date, time and URL. When the offer arrives, the history already exists.
- 02
A “was” price must be the genuine usual selling price
Great Britain has no fixed 30-day rule: the law treats false or misleading information, or a misleading overall presentation, as a misleading action (Digital Markets, Competition and Consumers Act 2024, section 226). The advertising regulator looks at how long the higher price was charged and expects advertisers to provide at least three months of pricing history. Here £398 was charged for seven days: the usual price was £210.
- 03
A history anyone can check
The report serves the shopper who doubts an offer, the small retailer who wants to audit a larger rival and the company monitoring rivals that discount off inflated prices. Where there are adverts, we submit the case file to the advertising platform; you or your adviser can report it to Trading Standards through Citizens Advice, or complain to the Advertising Standards Authority.
WHO IT IS FOR
The same history serves those who buy and those who compete.
Price monitoring is available to individuals and to businesses of any size.
01
Consumers
Before you buy, check what the product really cost over the past few weeks. If the saving does not add up, you have the history and the screenshots to back up a complaint.
02
Small retailers
Audit your larger competitors: check whether their campaigns start from prices that were genuinely charged. The Advertising Standards Authority accepts complaints from competitors, who must first show that they tried to resolve the matter with the advertiser.
03
Large companies
Monitor rivals that advertise discounts off inflated prices, in their shops and in their adverts, and document each case with a date, time and screenshot.
WHAT APPLIES IN THE UNITED KINGDOM
Three scenarios, one question: what did it really cost before?
Great Britain has no 30-day rule like the European one. Its law avoids prescriptive rules and relies on general principles of fair dealing, so the evidence that matters is the price history.
01
Fake discounts in adverts
The CAP Code says that price statements must not mislead and that price comparisons must not falsely claim a price advantage (rules 3.17 and 3.39). The Advertising Standards Authority expects a “was” price to be the genuine usual selling price, generally charged for longer than the promotional price, and asks advertisers for at least three months of pricing history.
02
Fake discounts in online shops
False or misleading information about a product, or an overall presentation likely to deceive the average consumer, is a misleading action (Digital Markets, Competition and Consumers Act 2024, section 226). Trading Standards guidance lists what makes a reference price genuine: how long the higher price was charged compared with the promotion, how recently it was charged, whether it was charged in the same channel and whether significant sales were made at that price. The Competition and Markets Authority can impose fines of up to £300,000 or, if higher, 10% of global turnover.
03
Fake discounts during sales events
In May 2026 the Advertising Standards Authority published a group of rulings on Black Friday promotions found by its own monitoring: one “was” price that had been charged for only 21 days was held to be misleading. Falsely stating that an offer is available only for a limited time is banned in all circumstances (Digital Markets, Competition and Consumers Act 2024, Schedule 20, paragraph 7).
What makes a reference price genuine, according to Trading Standards guidance
- The promotion does not run materially longer than the higher price was charged
- The higher price was charged recently
- It was charged in the same shop or channel
- There were significant sales at that price
Official sources consulted on 6 and 7 October 2026.
Illustrative caseVL / PRICE
What the advert saysHandbag −50%Black Friday · Was £398 · Now £198
Price over the last 30 days“Was” price shown£398Usual selling price£210Real saving6%
The rule
A “was” price must be the genuine usual selling price
Great Britain has no fixed 30-day rule: the law treats false or misleading information, or a misleading overall presentation, as a misleading action (Digital Markets, Competition and Consumers Act 2024, section 226). The advertising regulator looks at how long the higher price was charged and expects advertisers to provide at least three months of pricing history. Here £398 was charged for seven days: the usual price was £210.
Sales eventsRaising the price shortly before Black Friday does not make it the usual price. In 2026 the Advertising Standards Authority ruled that a Black Friday “was” price charged for only 21 days was misleading.
- 01Price recorded every day
- 02Advertised: was £398
- 03Usual price (30 days): £210
- 04Real saving: 6%
GLOSSARY
The terms and the sources, in plain view.
Every case is documented with sources and context. Scope is agreed for each market; the references on this page are to the law of the United Kingdom.
- “Was” price
- The earlier price shown next to the new one, also called the reference price. It must not mislead: it should be the genuine usual selling price.
- Savings claim
- Any statement that presents a price as reduced: a percentage, a crossed-out price, “was/now” or a “Black Friday deal”.
- Crossed-out price
- The “was” price struck through beside the new price.
- RRP
- Recommended retail price. Trading Standards guidance says it must not be false and must represent a genuine selling price.
- Usual selling price
- The price the product normally sells at. The Advertising Standards Authority generally expects the higher price to have been charged for longer than the promotional one.
- 30-day rule
- In the European Union the “prior price” must be the lowest price charged in at least the previous 30 days. Great Britain has no such fixed rule.
- Price history
- A day-by-day record of a product’s price, used to check what it really cost before the offer.
- Screenshot
- An image of the page or the advert as it was shown, with its date, time and address.
References
- Digital Markets, Competition and Consumers Act 2024, section 226 (legislation.gov.uk)
- CTSI: Guidance for Traders on Pricing Practices (Business Companion)
- CAP Code, section 3: misleading advertising (ASA)
- ASA: promotional savings claims
- ASA: Black Friday advice for advertisers (24 October 2024)
- Digital Markets, Competition and Consumers Act 2024, Schedule 20 (legislation.gov.uk)
- CMA: consumer protection drive on online pricing practices (18 November 2025)
- ASA: make a complaint
FREQUENTLY ASKED QUESTIONS
Those who inflate the price before cutting it gain an unfair advantage.
The “−50%” takes the clicks from the shop that keeps its price all month. A dated price history helps those who do not inflate prices to compete on equal terms.
How can I tell whether a discount is genuine?
By comparing the “was” price with the genuine usual selling price. Great Britain has no fixed 30-day rule: the Advertising Standards Authority looks at how long the higher price was charged and expects advertisers to provide at least three months of pricing history. VigiaLabs records the price of every monitored product each day, with a screenshot, date, time and URL: when the offer arrives, the history already exists.
A competitor advertises discounts off inflated prices. What can I do?
Document it with a dated price history. The Advertising Standards Authority accepts complaints from competitors, who must first show that they tried to resolve the matter with the advertiser. Where there are adverts, VigiaLabs submits the case file to the advertising platform; you or your adviser can complain to the Advertising Standards Authority or report it to Trading Standards through Citizens Advice.
Is there a 30-day rule for Black Friday discounts in Great Britain?
No, Great Britain has no fixed 30-day rule, but Black Friday is no exception: a “was” price must be the genuine usual selling price, and raising the price shortly before does not make it so. In May 2026 the Advertising Standards Authority published a group of rulings on Black Friday promotions: one “was” price charged for only 21 days was held to be misleading.
Can a consumer, a consumer organisation or a small retailer use it?
Yes. Price monitoring is available to individuals and to businesses of any size. A consumer checks what the product really cost before buying; a small retailer audits whether larger competitors’ campaigns start from prices that were genuinely charged. In both cases there are a price history and screenshots to back up a complaint.
Does a percentage or a crossed-out price in an advert count as a savings claim?
Yes. A percentage, a crossed-out price or a “was/now” in an advert is a savings claim: a statement that presents a price as reduced. The CAP Code says that price statements must not mislead and that price comparisons must not falsely claim a price advantage (rules 3.17 and 3.39), and the Advertising Standards Authority expects a “was” price to be the genuine usual selling price.
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