Sometimes you may not want your number appearing on caller ID when you’re on your iPhone. Many users don’t know there’s actually a way to turn this off.
To turn this off, go to the Settings app, and then scroll down and press the “Phone” option.
There, under the “calls” heading, you’ll see an option that says “Show my caller ID”.
Press that, and you’ll be given the option to turn it off. Do so, and your number will not show on outgoing calls.