The Security Loophole
The Apple Watch forces you to enter a 4-digit PIN code when you first strap it to your wrist in the morning. However, to save you time, Apple includes a feature called “Unlock with iPhone.” If this is enabled, simply putting the watch on your wrist and then unlocking your iPhone using FaceID will automatically unlock the watch as well. While convenient, this creates a massive security loophole. If you are sleeping or incapacitated, and someone places your watch on their own wrist while simultaneously pointing your iPhone at your face to unlock it, they instantly gain full access to your Apple Watch (including your emails, texts, and Apple Pay). For maximum security, the watch must be isolated.
How to Turn Off “Unlock with iPhone”
You can force the Apple Watch to rely exclusively on its own local PIN code via the security settings.
- Open the Settings app directly on your Apple Watch (the grey gear icon).
- Scroll down the main list and tap on Passcode.
- Scroll down the page to the section just below the main “Turn Passcode Off” button.
- Look for the toggle switch labeled Unlock with iPhone.
- Toggle this switch to the Off position (the green background will disappear).
The Isolated Device
The change takes effect immediately. The Apple Watch is now completely divorced from your iPhone’s biometric security. The only possible way to access the data on the watch after putting it on your wrist is to physically type the 4-digit PIN code into the watch’s screen, ensuring your data remains completely secure even if your iPhone is compromised.