call codes to hide your number
1 Android 4.1 & later - Open the Phone app>Menu>Call settings>Caller ID>Hide number. 2  iPhone - Open the Settings app>Phone>Show My Caller ID>toggle the slider to OFF. 3  Windows Phone 8 - Open the Phone app>More button (...)>settings>Show my caller ID to>no one/my contacts.  Your mobile operator should allow it.