In April 2018, WhatsApp modified the terms and conditions of use of its application to add a minimum age of users of its service.
Specifically, WhatsApp established that you must be at least 16 years old to use the application if you live in Europe, and 13 years if you live in any other region. Until now, that restriction had no effect but things could change with the next version of the app.
As the WABeatInfo website explains, the next version of WhatsApp implements a mechanism that will prevent the use of the application to users who do not meet the minimum age.
What is not clear is how the app will do to detect the user's age and if it will be possible to easily fool the app, as with many other apps that also have age restrictions.
Given that the app has 500 million active users (and 1.5 billion users per month), it will be difficult to control the age of all its users.