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

The card only has a serial number. It always has the same serial number, it never changes.

The door lock is only a reader. It reads the card number. Then it transmits that number to the hotel IT system.

When you check in, the front desk pulls a card (any card) from the pile and puts it on a reader. The system reads the card serial number and associates it with a particular room for a duration in a database.

When you walk up to the door, it reads that serial number, queries the database, and if the two match up, opens the door.