This Change Number feature helps you to change the phone number related with your WhatsApp account on the same phone. This feature is planned to be utilize before you verify your new number.
To use the Change Number feature will migrate your account information including picture profile information, groups and settings from your old phone number to your new phone number and also delete the account related with your old phone number.
With this feature, your chat history will still to be available on your phone with the new phone number.
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To Change Your Phone Number
1. Go to Settings => Account => Change Number.
2. Type your current WhatsApp phone number in the first box.
3. Type your new phone number in the second box.
4. Tap on Done to follow the process.
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