How to block and unblock numbers from the Samsung Contacts app Samsung’s Contacts app is the simplest way to block (and unblock) phone numbers using your Samsung handset.

Unfortunately, it's not possible to block phone numbers that are marked Private, Unknown, or No Caller ID. On Android, it doesn't send the caller to voicemail when you block them.

You can block a phone number or contact on Android from the Phone app, your contacts list, recent calls log, and more. Here's how to do it.