PSA: Don’t Change Google Password Right Before Factory Resetting Your Phone
If you are going to perform a factory reset on your phone, do not change your Google account password. Thanks to the new security feature Google is adding to the latest versions of Android, changing your password just before factory resetting your device will permanently lock your device for 72 hours.
Starting with Android 5.1 (or earlier, depending on your OEM), Android comes with some built-in device security features to help keep your phone safe in the event of theft. One of these features, Factory Reset Protection, requires you to sign in to your phone with the Google account you previously used to sign in. The idea here is that if a thief steals your phone and then immediately resets it, they won’t actually be able to use it unless they also have the credentials to log into your account.
“Well, what to stop the thief from resetting his password himself and using to get into his phone?” Good question! Since your phone can receive your two-factor codes and emails, gaining access to it makes it pretty easy to reset your password. For this reason, if someone changes the password on your Google account and then immediately reboots your phone, Google assumes that your device is in the hands of a thief and begins a 72-hour lockdown.
The idea behind blocking is that it gives you time to retrieve your phone, if stolen, before a thief can access it. If you really need to factory reset your phone and change your password, there is an easy solution: do a factory reset first. Once you’ve signed in to your new device, you can easily change your password. Alternatively (and this is probably even more secure): change your password, then wait at least three days before restarting your phone.
As Android Police points out, if you reset your device for sale, you need to manually disable the lock screen and completely delete your Google account. Not only is this another reason why you should lock your screen , but it will prevent you from having to sign in to your device after a reset.
Don’t Change Google Password Before Factory Resetting Android Phone – You Can Lock 72 Hour Security Lock | Police Android