Citi has announced that it is pilot-testing a new mobile banking feature that utilizes beacon technology to control access to selected ATM vestibules in New York City.

As the customer approaches the ATM, a beacon at the location communicates with the Citi app on customer's mobile device in order to authenticate the device and grant the user's request for access to the ATM.

With a simple touch of the device screen, the customer can unlock the vestibule and use the machine — without having to use a plastic card.

The graphic below illustrates how the technology works: