how to block phone number

Just don’t answer calls that you don’t know who they are 

Do you have VOIP (Digital) phone service?

If the *60 method is not working for blocking unwanted calls on AT&T, you can try an alternative method using AT&T's Call Protect service:

1. Download the AT&T Call Protect app from your phone's app store.
2. Open the app and follow the instructions to set it up.
3. Go to the "Block" section in the app.
4. Add the phone numbers you want to block by tapping on "Block Numbers."
5. Follow the on-screen instructions to confirm and block the unwanted numbers.