Activation Lock for iPhone, iPad, and iPod touch
If you ever misplace your device — whether it’s lost or you think it might have been stolen — you should immediately use Mark As Lost in the Find My app.
Mark As Lost locks your screen with a passcode and lets you display a custom message with your phone number to help you get it back. You can also remotely erase your device if needed. Your custom message continues to display even after the device is erased.
While Activation Lock works in the background to make it more difficult for someone to use or sell your missing device, Lost Mode clearly shows anyone who finds your device that it still belongs to you and can’t be reactivated without your password.
Learn what to do if your device is lost or stolen