Change Your WhatsApp Phone Number

If you’ve changed phone numbers but kept the same phone, you don’t need to uninstall and reinstall WhatsApp just to change numbers. There’s a setting

within WhatsApp that will let you migrate your WhatsApp account to a different phone number.

Go to Settings > Account > Change number. Enter your old phone number in the top field and then your new phone number in the bottom field. Then press  

Done. Verify your new phone number, and all your chat history, groups and so on will be migrated to the new number