WhatsApp is currently working on improving its Change number feature on iOS, Android and Windows phone. When someone gets a new number or changes his number on WhatsApp, it migrates the data to the new number preserving the chat history and will be automatically gets added to the groups that the old number is present and notifies group members.
However, WhatsApp is making changes to improve this feature further. With the 2.18.97 beta update for Android, users now have the ability to choose if they also want to notify some or all contacts. You can also choose to notify contacts who you have a chat with. This is really a very handy feature to have when users change the number and want to notify their contacts.
Instead of messaging individually, notifying users about the number change is simple and hassle-free. Even if you wish to not notify any of your contacts, groups will be notified regardless. After the migration, on the recipient’s phone all the old chat will be transferred to the new one and in the chat a new bubblewill appear, indicating that the user has a new number.
This new feature is currently only available on WhatsApp beta for Android, but will soon become available to iOS and Windows as well. If you are a beta tester, you can update the app directly from the Play Store.