Hotel door cards explained: how a key card system works

Most guests never think about hotel door cards. They tap, the door opens, and that is that. But behind every tap is a small system, and if you run a hotel you need to understand it, because it controls who can enter which room and when.

This post explains how a card lock system works in plain words, who does what, and what to ask before you buy.

The three parts

1. The lock. Each door has a lock that reads the card. It does not call anywhere. It holds its own list of rules, such as which rooms and dates the card may open, and decides on the spot. That is why a door still works if the internet is down.

2. The encoder. A small box connected to a computer at the front desk. It writes information onto a blank card: which room, which dates, what kind of card.

3. The software. The program the front desk uses. When a guest checks in, it asks the encoder to write their card.

What happens when a guest checks in

1. The receptionist opens the booking and chooses to make a room card.

2. The software works out the room and the dates, from check-in to check-out.

3. The encoder writes those details onto a blank card.

4. The guest taps the card on the door. The lock reads the dates, sees they are valid, and opens.

5. After check-out, the card stops working because its dates have ended.

Different kinds of cards

A hotel does not only use guest cards. Typical kinds are:

• Guest cards, for one room, for the stay.

• Master or building cards, which open many doors, kept by a small number of people.

• Floor or area cards, for housekeeping or maintenance on certain floors.

• Lost-key stops, a card that tells a lock to refuse a lost card.

Because a master card opens many doors, it is the most sensitive card in the hotel. Every time one is made, it should be recorded with who asked for it and why. Our post on how money goes missing in a hotel is about money, but the same rule applies to keys: if there is no record, there is no accountability.

Why the lock and the software must match

Every lock maker has its own system. The encoder, the cards and the software must all speak the same language. A card written by one make of encoder will not open another make of lock. So the first question when you buy locks is always: which software will make the cards?

If your lock supplier gives you a separate program that only they support, your front desk will type each guest twice: once in the hotel system, once in the lock program. That costs time and creates mistakes, like a card made for the wrong room.

What to ask before you buy locks

1. Which hotel software can make cards for these locks, so my front desk doesn't type each guest twice?

2. What kinds of cards can I make: guest, master, floor, lost-key stop?

3. How do I stop a lost card from working?

4. Can I see which doors were opened, and with what kind of card?

5. What happens if the encoder or the computer fails?

6. Who is trained to make an emergency card at night?

7. How does the lock know the time, and what happens when its battery runs down?

How Xenia handles it

Xenia can make guest cards and several special cards from the booking, and keeps a record of who made each one and why. A small program on the front desk computer connects the encoder to Xenia.

We are plain about the state of this: Xenia's Tengo encoder support is built and being proven on a real door in a pilot hotel. For other lock systems, ask us. The door locks page shows what is available today, and the door cards guides walk through each step, from connecting the encoder to making a card.

A simple rule

Treat keys like cash. Count them, record them, and know who holds each one. A hotel that can say exactly who has which card is a hotel that can answer quickly when something goes missing from a room.