Will Tesla Lock With Phone Inside?

This article explains how to use the Tesla Phone Key feature to unlock your car.  

The key fob and phone key app are designed as backups, but the Tesla Model 3 does not automatically lock when you walk away.  

You must first open the Tesla mobile app, and then touch the phone key to set it up.  

You can then unlock your car with just a touch of your smartphone. This is a great feature as you don't have to worry about carrying a key fob in your pocket or bag.  

To use this feature, simply touch the card on the top of the car and it will unlock.

The key app phone also offers the ability to override your Tesla's ability to lock with your phone inside.

so you don't have to worry about walking away from your car without being able to unlock it.