Mobile key

A room key issued to a guest's phone instead of a plastic card, letting them unlock their room by holding the phone to the lock.

The key is delivered one of two ways. Either it lives inside the hotel's own app or a vendor's guest app, or it is added to the phone's built-in wallet, such as Apple Wallet or Google Wallet, where it works without opening an app at all. Wallet keys generally feel faster to guests and keep working when the phone has no signal.

Making it work needs three things to line up. The PMS has to confirm the reservation is checked in and tell the lock system which room to open and for which dates. The lock has to support the right radio standard, usually Bluetooth Low Energy or NFC, which on older hardware means a retrofit. And something has to issue the credential, which is the job of the lock manufacturer's own software or a separate guest experience platform.

Two practical cautions. Mobile key only removes work at the front desk if guests can also complete check-in and identity verification without staff, otherwise they still queue. And a mobile key programme ties your door hardware, your guest app and your PMS together more tightly than most hotels expect, so check what happens to the integration if you later change any one of the three.