Here is the guide on how to block all incoming phone calls from numbers that are not in your contacts on Android phone: stock Android, Huawei, Xiaomi.
It’s quite simple to block a single caller on Android but what to do if you are attacked by a squall of calls from different strange phone numbers? Of course, you may ban them one by one but you will continue to receive unwanted calls from yet a new number each time.
In this case the white-list technology will help you out. You need to block all stranger (callers whose numbers are not added to your contacts) but let all your contacts easily reach you.
In this article we will explain how to block strangers using the built-in phone apps and do the same using third-party call managers.