To activate Whatsapp calling feature you must receive a call from another WhatsApp user that already has the feature unlocked, showing no change to the process that was implemented for WhatsApp Calling’s testing.

However, if the user being called up does not have the latest version of WhatsApp installed, a notification will be sent to request the user to update the app before the call is made. According to Android news website, after a user receives a call from another WhatsApp user with the WhatsApp Calling feature already activated, the user interface for the app changes, either instantly or after the user closes and then re-opens WhatsApp. The new user interface displays three tabs, labeled as calls, chats and contacts. Accessing the call feature can be done through the messages with any of the user’s contact, as a call button will appear as one of the options in the action bar for that user beside the attach option and the menu.