I’m with sky and all calls go through a check before it rings, asking them who is calling. I then get option to accept call or not. In reality none of them answer and hang up so it never connects to my phone. I have not had a single spam call in over a year. You simply add anyone to accepted callerzs list to avoid process and get straight through. Considering i used to get 4 or 5 calls a day its been a godsend.