If you change your mobile phone number you can migrate all your WhatsApp conversations and groups to that new line using the option Change number that hides the settings of the popular messaging application, and that now in its new version (beta) has been improved by adding an important option.
WhatsApp for Android now allows us send a notification to our contacts with the phone change, so that they know that we have a new mobile number to which they have to send us the messages now. You no longer have to write a message to your contacts, the application will do it for you.
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Change number in WhatsApp
To do this, the first thing we have to do is change the number in WhatsApp from Settings> Account> Change number. There it informs us that the account information, groups and settings will be migrated to the new number. Click on Next and proceed to put our old number and the new number.
In the next window we will see the new option Notify my contacts. If we activate it we see that we can inform all our contacts, only the contacts with a conversation or only certain contacts (Personalize) the change of our phone number. The notice will appear in all groups.
Telephone change notification
When our contacts are going to send us a message to our old phone number, a notification and a message will appear that informs them that we have changed to a new number. Clicking on this notice allows us send a message to the new number or add it to the phonebook. This way your contacts will not lose your contact.