Open WhatsApp and go to the Chats section. Select a contact from the drop-down menu, then tap New Chat > search for or select that person to remove. Tap the contact’s name at the top of the screen. Edit > scroll down to Remove Contact and press OK.
There’s no way to change the Select contact screen directly. To remove a person from your phone’s address book, you must first delete him or her from there. Find the WhatsApp contact in your phone’s address book by looking for it on the Select contact page.
You may simply edit a contact on your phone and move their phone number to the Notes section of your Contacts app if you only want to remove a contact or certain number from WhatsApp but still need the phone number for reference.
All of your chat data will be wiped away if you delete WhatsApp from your phone. You won’t be able to access prior communications with WhatsApp after you unlink it. Even though you backed up your iPhone using iCloud (iOS) or Google Drive (Android), and even though you reactivated your account, all of this material will be erased.
Whatsapp has a ‘Click to Chat’ option that allows users to start a chat with someone without having their phone number stored in their phone’s address book. When you click the link, a conversation with the individual is immediately initiated. This ‘Click To Chat’ works both on your phone and online through WhatsApp.