The first iOS 12 developer beta debuted after today’s WWDC keynote. Intrepid souls who’ve already installed this early version on their iPhone X noticed that Face ID can be trained to recognize more than one person.
This removes one of the significant limitations of Apple’s new biometric security system.
The old Touch ID can be used with multiple people. This allows, for example, a spouse to unlock their loved one’s iPhone.
That’s not possible with the current version of Face ID. Only one person can be recognized. Limitations like this will become more significant if rumors are correct and all three of the 2018 iPhone models launching this fall have Face ID.
iOS 12 multiperson Face ID to the rescue
On the iOS 12 Face ID & Passcode settings is a new entry: Set Up an Alternate Appearance. The description for this says “In addition to continuously learning how you look, Face ID can recognize an alternate appearance,” according to 9to5mac.

Photo: CultofMac
Apple’s intention for this seems to be to allow someone to train their device to recognize them under different conditions. But tests show that it can be used to train Face ID to recognize a second user.
Craig Federighi, Apple’s senior VP of Software Engineering, gave a runthrough of the new features in iOS 12 at this morning’s keynote. But multiperson Face ID wasn’t mentioned. Still, he and his team had to cover new versions of iOS, macOS, watchOS, and Apple TV in about 2 hours, and clearly there wasn’t time for everything.
This feature appears in a very early beta of iOS 12. It’s possible changes will be made before the official release this fall, and multiperson Face ID could be modified or even removed before then.