While no foolproof method exists to ensure that thieves won’t be able to turn off the Find My iPhone app, you can make it more difficult. Activating another option in your device’s settings can give you more time to track down your iPhone. Learn how to protect this feature using iOS 12 or later.
How to Protect ‘Find My iPhone’
To stop someone from turning off Find My iPhone, set up a restriction on your phone. This extra layer of security requires a unique password to disable the location services that the app uses. To make your phone even harder for a thief to compromise, consider making a stronger iPhone passcode instead of the default 4-digit number. Turning off this option removes the icon at the top of the screen that shows that an app or service is using your location. Someone who steals your iPhone won’t know that it’s sending its whereabouts when you locate it. After you’ve set a passcode, nobody can access the Content & Privacy Restrictions menu without it. The more time a thief has with your phone, the more likely they are to circumvent your security. The above measures will at least put up a few roadblocks for them, giving you additional time to track down your iPhone.