Final answer:
To change your caller ID name on an iPhone, contact your carrier directly as the name is set by them, not your device. You can update your contact information in the settings for emails and messages, but not for the caller ID name displayed during calls.
Step-by-step explanation:
To change your caller ID name on an iPhone, you generally need to contact your carrier, as the caller ID name is usually set by them, not the phone itself. Most carriers have an online portal or customer service line where you can request a caller ID name change. After the carrier updates the name, it may take a few days for the changes to be reflected on the receiver's end when you call them.
If you are referring to the display name associated with your phone number for outgoing emails or messages, you can go to Settings, then tap Phone, and then tap My Number to update your contact information on your iPhone. This will not alter the caller ID name displayed during a phone call, though.