Before you sell your old iPhone or give it away, take a few minutes to erase the phone's memory. Smartphones store all sorts of personal information you don't want falling into the wrong hands, and protecting your identity only takes a few moments. Even if you've lost your phone or worry someone might have stolen it, it's not too late to erase the phone's data as long as you had Find My iPhone turned on.
Back Up First
Before you erase your iPhone's data, make sure you have a . The iPhone regularly backs up either to iCloud while charging and online, or to iTunes when you sync with your computer, so most of the time, you'll already have a recent backup. To create an iCloud backup manually in iOS 8, open the Settings app, select iCloud and then select Backup. Tap Back Up Now.
Or, in iTunes 12, open your iPhone's Summary tab and click Back Up Now.
Erase Your Data
Erasing your iPhone's entire memory is both the easiest and most comprehensive way to clear your personal information. By erasing the phone, you remove your Apple ID, your apps, your contacts, your saved data and even your phone number from the phone's memory. Everything on the phone returns to like-new condition, except the iOS version -- this process won't revert the phone to an older version of iOS.
Before you can erase an iPhone, you have to turn off Find My iPhone, if you have it enabled. Open the Settings app, go to the iCloud settings, tap Find My iPhone and switch the feature off.
Open the General settings in the Settings app and choose Reset at the bottom of the page.
Choose Erase All Content and Settings to wipe your personal information and return the phone to its factory settings.
Confirm the choice by entering your lock screen code, if you have one, and tapping Erase iPhone.
Erase Data Remotely
If you lose your phone, use Find My iPhone on the iCloud website to erase it remotely. Unfortunately, you won't be able to create a new backup before erasing your phone, but you help mitigate your risk of identity theft.
Log in to the iCloud website with your Apple ID and click Find My iPhone. Open the All Devices menu and choose the phone you want to erase.
Click Erase iPhone beneath the phone's image. Another option, Lost Mode, locks your phone down if you think you can recover it and don't want to erase it yet.
Click Erase to confirm. Afterward, the site asks you to provide your password again. On iOS 7 and above, you can also provide a phone number and message to display on the phone's screen in order to help recover your phone if someone finds it.