in hotels, if you lose your room key card, how are they able to reprogram the new one so it works and the old one doesn’t?

Question

Is there some system that transmits information to your door card reader on what the new key is, or is it something different entirely?

In: 1028

Answer 1

Many modern electronic card locks use a rolling code system: the lock is preprogrammed with a set of guest key IDs it expects to see

If the lock sees any of the next code in sequence, it assumes that the previous guest have checked out or replaced their card, and will refuse to accept that previous card