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

card 43782 opens room 220
Card lost
clerk disables card 43782
new card 90661 now opens room 220