How to blacklist iphone?

If you are viewing the recent calls interface in the phone application, click next to the phone number or contact you want to block. Scroll to the bottom of the screen, and then click Block this call number.

If you are checking email, please open the conversation, click the contact at the top of the conversation, and then click. Tap a name, phone number, or email address, scroll to the bottom of the screen, and then tap Block this incoming number.