How to prevent others from using your Android device without permission

You can set your phone to help prevent others from using it if it gets reset to factory settings without your permission. For example, if your protected phone got stolen and erased, only someone with your Google Account or screen lock could use it.Note: Some of these steps work only on Android 8.1 and up. 

Set up phone protection

1. Add a Google Account on your phone: To help prevent other people from using your phone if it gets erased, add your Google Account to your phone. 
2. Set a screen lock: To help prevent other people from using or erasing your phone, set a screen lock. 

Tip: If you don’t have a screen lock set, you might be able to lock your phone remotely with Find My Device. 

Turn off phone protection

To turn off phone protection, remove your Google Account from your phone.

If you have Developer options turned on, you can also turn off phone protection from your phone’s Settings app. Tap System  Advanced  Developer options  OEM Unlocking.

Expect to verify your ownership after factory reset

To factory reset a protected phone, you’ll need to either unlock your screen or enter your Google Account password. This ensures that you or someone you trust is doing the reset.

Expect to unlock your screen or enter Google Account information if you:

• Erase your phone’s data using the Settings app:
  You’ll be asked to enter your screen lock before you reset.
• Reset your phone using its buttons:
  If you reset your phone using its buttons (Recovery mode), you’ll need to enter your PIN, password, or pattern. You’ll also see an option to use the Google Account that was on your phone before you reset it.
• Remotely reset your phone with Find My Device:
  If you remotely reset your phone using Find My Device, you’ll need to enter a Google username and password associated with the phone.

Note: You can sign in with any Google Account previously added and synced to the phone as an account or user, but not as a guest. If you can’t give this information during setup, you won’t be able to use the phone at all after factory reset. If you can’t sign in to your Google Account, get sign-in help.