WhatsApp does not have any subscription fees. The app is free to download and use for messaging and calls, as long as you have an internet connection. To use the app, simply download it from the App Store or Google Play Store, verify your phone number, and start chatting with your contacts.
Learn more about how to set up your profile in WhatsApp: Android | iPhone | Windows Phone| Nokia S40 | BlackBerry | Nokia S60 | BlackBerry 10
Cheers,
WhatsApp Support Team