You can't block an incoming number (unless it becomes a police matter).
You can't block an outgoing number ('cause you can just not dial the number?)
Reading between the lines, the phone isn't used by you and you want to stop two people communicating?
Yes you CAN block an incoming number by adding it to your blocked number list. Then when they ring they will go straight to voicemail but you will receive a missed call message.
I use this feature on my iPhone for telemarketers that don't take no for an answer. They soon get the message.
I want to be able to block numbers from people and not get any notification when they call, blocked callers should not be able to leave voicemail either - the notification is almost as annoying! Why can't a recorded reply to blocked callers be "your number has been blocked by the account holder - you will not be connected at this time" .......?
The industry just doesn't seem to support this functionality. In fairness it is trivial to circumvent any such block (use anther phone, or sales staff just change their caller id, etc.)
If you're receiving calls from a number that are unwelcome we'd recommend reading our page on How to stop unwelcome calls, scam calls & messages.
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