This wikiHow teaches you how to prevent callers with blocked numbers or who aren't in your contacts from getting through to you on your iPhone.
EditSteps
EditUsing Do Not Disturb
- Open your iPhone's Settings. It's a gray app containing gears on your iPhone's home screen.
- Tap . It's in a section near the top of the menu, next to a purple icon with a moon inside it.
- Tap . It's midway down the screen
- Tap . It's located in the "Groups" section of the menu. Now, when "Do Not Disturb" is enabled, only numbers in your contacts will get through.
- Swipe up from your home screen or lock screen and tap the round, crescent moon icon at the top of the Control Center to turn Do Not Disturb on or off.
EditBlocking Calls Labeled as "Unknown"
- Open your Phone app. It's a green app in the lower left corner of your iPhone's home screen. It contains a telephone icon.
- Tap . It's in the bottom center of the screen and contains the silhouette of a person.
- Tap . It's in the upper-right corner of the screen.
- Type "Unknown" into the first and last name fields.
- Tap . It's in the upper right corner of the screen.
- Tap . It's at the bottom of the screen.
- Tap . Now, most calls labeled as "Unknown" should be blocked from your iPhone.
- Friends calling from an unknown number will not be able to reach you.
EditBlocking Calls from Numbers You Don't Recognize
- Open your Phone app. It's a green app in the lower left corner of your iPhone's home screen. It contains a telephone icon.
- Tap . It's a clock icon in the bottom left corner of the screen.
- Tap next to a number you don't recognize. It's a blue icon on the right side of the screen.
- Scroll down and tap . It's at the bottom of the menu.
- Tap . Now, calls from this number will not reach your iPhone.
EditWarnings
- If a friend or family member is calling you from an blocked number or a number that's not in your contacts, they won't be able to reach you on your iPhone.
Source: http://www.wikihow.com/Block-Calls-from-Unknown-Numbers-on-an-iPhone