How to block all unknown calls on Xiaomi phone running MIUI V5 ?

Blocking all unknown numbers on your Xiaomi phone is easy. Here’s how:

1. On your Xiaomi phone, find and launch the Security app.
2. Tap Blocklist.
3. Tap Settings.
4. Tap Rules.
5. You should see the following 4 predefined rules:
   1. Block numbers
   2. Only allow contacts
   3. Only allow exceptions
   4. Block everything
6. Select Only allow contact. This only allows messages and calls from numbers in your Contacts. The private and unknown numbers are blocked.
   

Note: You can tap  next to all the rules to see the details.

Note: The steps here were written for a Xiaomi device running MIUI V5. If you’re having a different version of MIUI, there’s a possibility that the steps and screenshots will be different.