When Caller ID was invented, it was expensive to make telephone calls and required special equipment to set the Caller ID. Because of the cost, the telephone network did not authenticate the Caller ID. Now, anyone can place a call anywhere in the world and it costs almost nothing to make calls. Believe it or not, the caller chooses the Caller ID when they place a call on the telephone network today. There is no verification at all.
This is necessary and used legitimately all the time in cases like doctor’s appointment reminders, school announcements, etc. The downside of this is that telemarketers can and do also use this technology to spoof numbers. They don’t really HAVE these numbers, they just present the number as they call. It is similar to you writing any return address you want on an envelope that you mail.
As telemarketers use a new Caller ID, it can take a while before the spam detection services recognize it as fraudulent. It is a very difficult problem to solve right now. The industry is working on a solution but in the meantime, CallHero, with the feedback of our users, is here to help support spam detection services identify these number more readily.