Unlock with Apple Watch on Mac stops working after a day

Apple Watch Unlock on MacBook Air Stops Working After a Day

If you have Unlock with Apple Watch enabled on your MacBook Air, but find that it stops working after approximately a day and requires you to enter your password or use Touch ID again, there are a few things worth understanding.

1. Apple does impose security-related password requirements, but it is important to distinguish between Touch ID and Apple Watch Auto Unlock.

• Touch ID requires your account password after 48 hours without unlocking your Mac, among other security-related circumstances.

• Apple also documents a 156-hour (6.5-day) password requirement under certain additional conditions.

• However, Apple does not document a daily or weekly expiration period for Apple Watch Auto Unlock.

Apple's stated behaviour is that after manually entering your password following startup, restart, or logout, your Apple Watch should automatically unlock your Mac when it wakes from sleep.

In other words, having to enter your password every day is not an established Apple Watch security requirement.

Apple references:

• Use Touch ID on Mac

• Apple's Biometric Security Requirements

• Unlock your Mac with Apple Watch

2. Check your Apple Watch and Mac settings

Make sure that:

• Wi-Fi and Bluetooth are enabled on both devices.
• Both devices are signed into the same Apple Account.
• Two-factor authentication is enabled for your Apple Account.
• Your Apple Watch has a passcode, is unlocked, and is being worn.
• Your Apple Watch is close to your Mac.

3. Reset the Apple Watch Auto Unlock connection

Apple recommends the following troubleshooting procedure:

1 On your Mac, open System Settings >> Touch ID & Password.

2 Find the Apple Watch section and turn off the option to unlock your Mac with your watch.

3 Restart your MacBook Air.

4 Return to the same settings and turn Apple Watch unlocking back on.

5 Test whether the feature continues working over the next several days.

4. Check for software updates

Make sure both macOS and watchOS are running their latest available versions. If this problem began after a recent software update, it could be related to an Auto Unlock software or connectivity issue.

Also, check whether your Mac is unexpectedly restarting overnight. Any restart requires you to enter your password manually at the next login.

5. What if the problem continues?

If you still need to enter your password every 24 hours or so, despite having successfully unlocked your Mac in between, I would suspect an Auto Unlock reliability issue rather than a normal Apple security timeout.

Unfortunately, Apple does not provide a setting to extend the Auto Unlock authentication interval.

You can also consult Apple's troubleshooting instructions here:

Apple Support – Unlock your Mac with Apple Watch

Bottom line: Apple Watch Auto Unlock is designed to continue working when your Mac wakes from ordinary sleep, without requiring daily password authentication. There is no documented 24-hour expiration rule or user-adjustable timeout. If the feature stops working after approximately one day, it is worth investigating as a potential macOS, watchOS, or connectivity issue rather than accepting it as normal behaviour.

That's a good question, and I should clarify the distinction.

Yes, Touch ID and Apple Watch Auto Unlock are two separate authentication methods, although both operate within Apple's overall security framework.

Here's how to understand the requirements:

• 48 hours: If you haven't unlocked your Mac for more than 48 hours, Apple requires you to enter your account password rather than relying on Touch ID.

• 156 hours (6.5 days): Apple also documents a password requirement when 156 hours have elapsed since the last password entry and biometric authentication hasn't been used within the preceding four hours.

However, these are documented biometric security requirements, not a published expiration schedule for Apple Watch Auto Unlock.

Apple's documentation specifically states that after manually entering your password following startup, a restart, or logout, your Apple Watch should subsequently unlock your Mac when it wakes from ordinary sleep.

Therefore, I would not expect you to have to enter your password every 24 hours simply because you're using Apple Watch Auto Unlock.

Unfortunately, Apple doesn't specify a separate maximum period during which Apple Watch Auto Unlock remains available, so I wouldn't want to promise that it will necessarily work for 6.5 days.

My recommendation: Continue with the troubleshooting steps outlined earlier. If you consistently encounter this problem after approximately 24 hours, even though your Mac hasn't restarted or logged you out, I would investigate it as a possible Auto Unlock reliability issue rather than assume it is a normal security requirement.

For reference, Apple's documentation is here:

Apple – Unlock your Mac with Apple Watch

Apple – Biometric Security Requirements

I hope that clears up the distinction!