Hold it near the door lock for a moment and the electronic reader inside powers the card using a radio signal, in turn, sending the chip serial number back to the reader to identify the card. The reader usually produces a beep and the light on the lock changes green to indicate the card has been read.

Hotel RFID (Radio Frequency Identification) key cards work through electromagnetic induction. Unlike magnetic stripe cards that require a "swipe," RFID cards contain a tiny chip and an antenna coil embedded inside the plastic. When you bring the card near the door lock, the reader emits a low-power radio signal. This signal creates a magnetic field that "powers up" the chip in the card wirelessly. The chip then transmits a unique, encrypted identification code back to the reader via radio waves. The door's internal computer checks this code against the database of authorized guests for that specific room and time slot. If it matches, the lock disengages. In 2026, this technology is the industry standard because it is more durable than magnetic strips—which are easily erased by smartphones—and allows for "contactless" entry. Modern systems are also highly secure, using 128-bit encryption to prevent hackers from "cloning" cards or intercepting the signal as it travels between the card and the lock.