alt Hacker NewsUsually the advertised price must be honored, because it may have brought the customer to your store.
For prices displayed on the shelf-label inside the store the law is usually not that strict (YMMV), as a shop-owner can refuse sale on check-out (otherwise I could put a pricetag on e.g. a shopping-basket and the shop-owner would be legally required to sell me the basket...).
Besides, most shops I've seen (in Europe) already moved from Infrared communication to RF (NFC or proprietary), for centralized shelf-label management without handheld devices. So all this study (and the underlying reverse engineering of the IR-protocol) might do is probably accelerate the transition from IR to RF-based ESL...
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It definitely varies by jurisdiction, but the register price always loses to any printed price in the US states I’ve lived in. This is a protection since retailers have used pricing mistakes to unfairly profit. Watch your receipt like a hawk at the dollar store[0]
[0] https://www.theguardian.com/us-news/2025/dec/03/customers-pa...
How is the transport medium changing anything?
To me this is about having protocols that are suitable so not anybody can write to these labels without knowing a store secret or using replay attacks.
> Usually the advertised price must be honored, because it may have brought the customer to your store.
This is not the case for groceries in Massachusetts at least. If there’s a discrepancy between the tag’s price and the scanned price the store must charge the customer the lowest of the two: https://www.mass.gov/price-accuracy-information