Nokia Lumia 635
Turn your own caller identification on or off
You can turn off your own caller identification, your number will then not be shown at the receiving end when you make a call. Your number is only hidden when you make voice calls not when you send messages.
1. Find "settings"
Press the phone icon.
Press the dots in the bottom right corner of the display.
Press settings.
2. Turn your own caller identification on or off
Press the field below "Show my caller ID to".
Press everyone, no one or my contacts.
3. Return to the home screen
Press the home icon to return to the home screen.