By the SightShield team · · 3 min read
How keycard locks work
Each room has a battery-powered electronic lock. At check-in, the front desk uses software and an encoder to write a key to an RFID card for that room and those dates. The lock checks the card when it is presented and opens only if the room and time are valid. At check-out, the key simply stops working; issuing a new key can also cancel older cards for the room.
Because the locks are battery powered, they keep working through power cuts. Most systems warn the front desk when batteries are running low.
Card types
| Card type | Notes |
|---|---|
| Magnetic stripe | Old technology; wears out and is easy to copy. Replace if still in use. |
| Basic RFID (e.g. MIFARE Classic) | Widely used but older encryption has known weaknesses |
| Secure RFID (e.g. MIFARE DESFire) | Stronger encryption; recommended for new installations |
| Mobile keys | Phone used as the key via Bluetooth or NFC, on supported locks and apps |
Staff access levels
- Guest cards: one room, the stay dates only.
- Housekeeping cards: assigned floors, working hours only.
- Maintenance cards: plant rooms and assigned areas.
- Manager and emergency cards: all doors, tightly controlled.
- Common areas: lifts, gym, pool and parking can be added to guest cards for the stay.
Audit trails
Each lock records which card opened it and when. After a complaint about a missing item or a disputed entry, the manager can read the lock’s history and match it with CCTV of the corridor. This record is one of the main advantages over mechanical keys.
Front-desk software and integration
The lock system’s front-desk software issues and cancels keys. Integrating it with the hotel’s property management system (PMS) means keys are encoded directly from the booking, with the right room and dates, without retyping. Check that the lock brand supports your PMS before buying. The same cards can also control lifts, the gym, the pool and car park barriers for the stay.
Energy-saving key card switches
Many hotels pair door locks with in-room key card switches: the guest inserts the card to power the room’s lights and AC, which switch off a short time after the card is removed. This saves energy in empty rooms. Using validated switches that accept only the hotel’s cards stops guests leaving any card in the slot.
Security lessons
In March 2024, security researchers disclosed “Unsaflok”, a set of vulnerabilities in dormakaba’s Saflok hotel locks that could let an attacker forge keycards; the manufacturer released fixes that required updating locks, cards and software across affected properties. The lesson for every hotel, whatever the brand: choose locks with current secure card technology, keep the lock and front-desk software updated, and make sure your supplier will support updates for years.
Smart Door Locks for Indian Homes →Installing in a running hotel
Locks are typically fitted floor by floor, with each room out of service for a short time. The survey checks door thickness, frame type and existing lock cut-outs so the new locks fit cleanly. Front-desk staff are trained on the encoder and software before the first floor goes live.
See our hotel lock service →Quick answers
Can keycard locks be fitted on existing hotel doors?+
In most cases yes. We check door thickness and frames on the survey and advise on any changes.
How long do lock batteries last?+
Typically many months to over a year depending on use and model. The software warns when batteries are low.
Are mobile keys worth it?+
For hotels with a booking app or many repeat business guests, they reduce front-desk queues. Keycards remain the default for most guests.
Do the locks work during a power cut?+
Yes. Each lock runs on its own batteries.
Can the lock system work with our PMS?+
Many lock systems integrate with common hotel PMS software. Confirm compatibility with your PMS before buying.
What happens if the front-desk PC fails?+
Existing keys keep working because locks run independently. Keep a backup encoder or PC for issuing new keys.