If you’re using WhatsApp, there’s a good chance that you’ve heard of the feature called “Unknown Numbers.” This is a way for you to block any number that you don’t know. To do this, open up your WhatsApp app and go to the “Settings” menu. Then, under “Privacy” tab, select “Unknown Numbers.” Now, type in the number that you want to block and hit the “Block” button. You’ll be asked for your phone number and your permission to block this number. Once you’ve granted this permission, your WhatsApp app will start blocking that number from being called.