Using the Delete My Account feature in WhatsApp will:
- Delete your account from WhatsApp.
- Delete you from your friends' WhatsApp Favorites lists.
- Delete you from all WhatsApp groups.
- Delete your WhatsApp message history on your phone and your WhatsApp backup.
To delete your WhatsApp account
- Open WhatsApp.
- Go to Options > Settings > Account > Delete My Account.
- Give us feedback (optional).
- Select Next to enter the number you registered with WhatsApp.
Learn how to delete your account on: Android | iPhone | Windows Phone