How to Delete the Data on Your Lost iPhone
If you lose your iPhone, what are your options? Well, hopefully a good Samaritan has found your phone and will return it. If you can’t get that other person to return your iPhone and it contains sensitive or confidential data, you can use the Find My iPhone app or the iCloud Find My iPhone feature to take the drastic step of remotely wiping all the data from your iPhone.
Here’s what you do:
Display the My Devices list.
Tap or click your iPhone in the list.
Find My iPhone locates your iPhone on a map.
Tap or click Erase iPhone.
Find My iPhone asks you to confirm.
Tap or click Erase.
Find My iPhone prompts you for your Apple ID password.
Type your password and then tap or click Next.
Find My iPhone asks you to enter an optional phone number where you can be reached, which will appear on the iPhone after it has been erased.
Type your phone number, and then select Next.
Find My iPhone prompts you to type a message that will appear on the iPhone along with the phone number, after it has been erased.
Type the message, and then tap or click Done.
Find My iPhone remotely wipes all data from the iPhone.