In the same way you can block phone numbers that you don’t recognize or contacts you’ve saved in your address book, you can also unblock them via the Phone app, so they can resume calling capability. Most Android phones have Google’s stock Phone app preinstalled. If your model happens to have the manufacturer’s phone app set as default, the steps for unblocking a number should still be pretty similar. Here’s how to do it for phones that have Android 6.0 or later installed:
Launch your Phone app, either through your phone’s main screen dock or by pulling up the app drawer and searching “Phone.”
Hit the three-dot icon located in the top-right corner of the screen.
Head to “Blocked numbers.”
Find the number you want to unblock from the list and tap the “x” icon next to it.
Confirm the action by hitting “Unblock.”
Once you unblock a phone number, it will once again be able to contact you at any time. However, any calls that the person made while the number was blocked won’t show up in your call history.