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

Key cards are merely numbered cards that broadcast their numbers.

The magic is actually in the door lock and server. The door look reads the card, it sends that signal to the server, the server decided if that specific card can open the door.

This allows multiple cards to open the door. Housekeeping cards, hotel staff, extra cards you can pay for. It’s actually not a big deal, but they make it seem like a big deal.