In this tutorial, you will learn how to:

• Block or unblock recent callers
• Manage blocked numbers through Settings

You cannot block an Unknown Caller (No Caller ID), but you can turn on Do Not Disturb manually and set it to "Only allow calls from your contacts list." The call blocking feature may not affect phone calls made or received via third-party apps installed on your device. Please contact third-party app developers for assistance with such applications.

Learn more from the Apple support articles: Block calls and block or filter messages on your iPhone and Use Do Not Disturb on your iPhone.

Block or unblock recent callers

From the home screen, select the  Phone app.

BLOCK A CALLER:  Select the Recents tab then select the Info icon next to the contact or phone number you want to block. 

Scroll to and select Block this Caller, then select Block Contact to confirm. 

UNBLOCK A CALLER: From the desired contact screen, scroll to and select Unblock this Caller.

Manage blocked numbers through Settings

VIEW BLOCKED NUMBERS: From the home screen, select the  Settings App > scroll to and select Phone > Blocked Contacts.

BLOCK A CONTACT: From the Blocked screen, select Add New... then select the desired contact that you would like to block.

UNBLOCK A CONTACT: Select Edit. Select the  Remove icon next to the desired contact then select Unblock to confirm. When finished, select Done.