Nomorobo utilizes a MASSIVE database of known, illegal robocallers, that we've compiled with the help of the FTC, user reports, and our own honey traps. The blacklist contains over 2.5 Million robocallers and grows every single day.
If a call gets a match in our database, we grab the call. If there's no match, we let the call go through.
We also maintain a growing whitelist of numbers we will never block.
You can also report calls to be added to the blacklist or whitelist using the 'Report A Number' feature in your Nomorobo account, or the 'Lookup' feature in the app.