Similarly to other messaging platforms, WhatsApp Messenger includes a blocking capability that allows users to restrict contact with any user with whom they'd no longer to communicate.
When you block a user on WhatsApp, you are essentially severing all means of communication between yourself and the contact. Blocked users will not show up in your contact list, their messages will not be delivered to your phone, and they will no longer be able to see any of your updates (i.e. profile picture, status, etc.). This tutorial will teach you how to block and unblock contacts on WhatsApp Messenger. Note that the below methods apply to Android and iPhone users.
Block a WhatsApp Contact on Android
Launch WhatsApp and then tap on MenuSettings > Account > Privacy > Blocked Contacts.
You will see a list of all currently blocked contacts. To add a contact to this list, tap on the Add button in the top-right corner of your screen. Then select the contact you'd like to block from the list:
Confirm by tapping OK.
If you'd like to block a contact who is not saved in your phone, you may do so by simply opening the chat with the unknown contact and selecting Block.
Unblock a WhatsApp Contact on Android
To unblock a WhatsApp contact on Android, tap on the Menu button, and then head to Settings > Account > Privacy > Blocked Contacts.
Tap and hold on the contact's name and then select Unblock from the pop up menu that appears.
Alternatively, you may also just send a message to the contact's number to reinstate contact.
Block a WhatsApp Contact on iPhone
To block a contact that is already in your address book, simply launch WhatsApp and head to Settings > Account > Privacy > Blocked. Tap the Add New button to select a contact from your list:
If you'd like to block a contact who is not saved in your phone's address book, you may do so by simply tapping the Block option in the conversation screen.
Unblock a WhatsApp Contact on iPhone
To unblock a contact, simply open your Blocked list via your WhatsApp Settings, scroll to the contact you'd like to unblock, and then slide your finger to the left across the contact name. Then tap the Unblock option.