How to spot it
- The price moves when nothing about the purchase has. Same dates, same seat, same afternoon.
- A private window, a different device, or a logged out session produces a different number.
- The price rises after repeat visits, which reads as scarcity and is more often recognition.
- A price shown in an app differs from the same item on the same company's website.
- There is no explanation offered anywhere for why this price is this price.
Why it works on you
A price feels like a fact about a thing rather than a proposition about you. Nobody checks a number that presents itself as the number, and the comparison that would reveal it, the same page seen by someone else at the same second, is exactly the comparison a single shopper cannot make. The practice survives on that asymmetry rather than on any cleverness in the pricing.
What to do
- Check in a private window before you buy anything expensive. It costs one keystroke and is the only test available from your side.
- Compare across a device that is not yours where you can, since profiles follow the device more closely than the person.
- Distinguish it from dynamic pricing. A price that moves for everyone at once is supply and demand; a price that moves only for you is not.
- In the EU, ask the trader whether the price was personalised. They may have been required to tell you already.
Where the law stands
Since the Omnibus Directive, Article 6(1)(ea) of the EU Consumer Rights Directive requires a trader to inform the consumer where the price has been personalised on the basis of automated decision-making, so that the consumer can decide whether to enter the contract knowing that. It is a transparency duty rather than a ban: personalised pricing is permitted and must be declared. The scope is narrower than it first appears, and it is generally not read as covering ordinary dynamic or real-time pricing that applies to everyone. Pricing that differs by a protected characteristic raises separate and much harder problems under equality law. The United Kingdom did not adopt this amendment after leaving the Union, so a reader in Britain has no equivalent disclosure duty to point at.
This is a description of published regulation, not legal advice, and rules in this area have changed more than once. The sources below are the primary ones.