Lifehacker: “In the time it takes you to watch the video above, you will probably receive 3-5 spam calls. Or at least it feels like that. Robocalls are hard to block because they 1) always come from a different number and 2) often come from your own area code, to make you think it’s someone you know. While you can’t block all the spam numbers, and scammers are always figuring out new ways to get through the phone lines, there are still some things you can do to do limit the number of robocalls you receive. In iOS 13 or later, you can stop unknown numbers from ringing at all by selecting “silence unknown callers.” The call will go straight to your missed call, but will at least buy you some peace of mind. On many Android phones, you can open up your default caller ID and spam options and enable “filter spam calls,” “see caller and spam ID” and “verified numbers.”..