In iOS 14.5 and watchOS 7.4, Apple introduced a feature that would allow mask wearers to unlock their iPhones with a paired and authenticated Apple Watch, eliminating the need to constantly enter a passcode. Now the company wants to provide clarity.
Apple now has a support document published, which describes how the Unlock with Apple Watch feature works and what requirements must be met for it to work. Apple says that the Apple Watch unlock process does not use Face ID to recognize and authenticate users, so the same facial scanning that allows Face ID to unlock your phone does not occur here.
“Unlock with Apple Watch” must be explicitly activated
There are a number of specific requirements that allow the Apple Watch to authenticate your identity to unlock an iPhone. You need an iPhone X or later with iOS 14.5 or later and an Apple Watch Series 3 or later with watchOS 7.4 or later, which must be paired together. Both Wifi and Bluetooth must be enabled for communication between the iPhone and Apple Watch, and the Apple Watch must have a passcode. Wrist detection must also be enabled. In addition, unlocking with the Apple Watch must be explicitly turned on for it to work. Users can find the feature under Settings -> Face ID & Passcode.
iOS 14.5 & watchOS 7.4: Function has proximity requirement

In order for the Apple Watch to authenticate your identity, the watch must be on your wrist and unlocked. You must also wear a mask that covers both your mouth and nose, presumably to signal the iPhone to use the secondary unlock method instead of Face ID. To unlock the iPhone with the Apple Watch, you must wake your iPhone by lifting it or tapping the screen and then glancing at the device. The requirement to look at the iPhone is intended to prevent the feature from working if you are not near your iPhone. Although it is not mentioned by Apple, there definitely seems to be a proximity requirement as well, as it will signal you when you are not close enough to the phone.
“Unlock with Apple Watch” should be used with caution
Unlock with Apple Watch is a feature that can theoretically allow another person to unlock your iPhone if they are near you, have your iPhone, and are wearing a mask. Therefore, enabling it should be done with caution. If other people have access to your device and you are concerned about security, you may want to avoid it. Additionally, it should be mentioned that Unlock with Apple Watch only works to unlock the iPhone. It does not verify identity for use with Apple Pay, keychain passwords, or password-protected apps that require either Face ID or your lock code. Although not as secure as Face ID, Unlock with Apple Watch is a convenient option for those who are tired of having to enter a password on their devices while wearing a mask. Still, use the feature wisely. (Photo by BackyardProductions / Bigstockphoto)