Knowing fully well that we can block calls from unwanted numbers by adding the particular number to black-list, but we can't do that for unknown numbers and no caller ID because there is no specific number to add. So why can't we block calls from unknown numbers on an iPhone? We surly can! But only on an iPhone for now.

We will give you 4 simple steps to prevent these unwanted and unrecognized numbers from coming into your iPhone.

Source: http://www.inforetweet.com.ng/2017/05/block-calls-from-unknown-numbers-on-iphone.html

Please use this only when you don't want to receive any unknown call with 'Unknown number' or 'caller ID' on your phone. This is done by using 'Do not disturb' in your iPhone settings.

There are three methods you can use in doing this like;

1. Using do not disturb
2. Blocking calls labeled as 'Unknown'.
3. Blocking calls from numbers you don't recognize...