Dial *67 before the number you want to call
Dial #31# before the number if you are in some countries that support it
Check your phone’s call settings for “Show My Caller ID” or “Caller ID” and turn it off
Use your carrier’s caller ID blocking code if different from the options above
Contact your mobile carrier to enable permanent caller ID blocking
Use a VoIP or calling app with caller ID blocking settings
Make sure the number is not being blocked by emergency services or toll-free call rules