Whatsapp is linked to your phone number. When you get a different number it is possible to change your number ans you can keep using Whatsapp?
- Make sure that the new phone number works so you can receive an SMS
- Go to Settings ->Account -> Change number
- Enter your old number in the first field and your new number in the second field. Then click Save .Your old number will be deleted from the database and WhatsApp your new number is being verified.If you need a Android or a Windows Phone it is not possible to change your number. You need to remove your old account and then you can add a new number and verify it.