When you first set up your device, you're prompted to create a BlackBerry ID, or you can sign in using an existing BlackBerry ID. Once you finish setting up your device, you're automatically signed in to BBM.
When you create a new BlackBerry ID, you can use either an email address or a phone number as your BlackBerry ID. If you use an email address as your BlackBerry ID, you receive a confirmation email message. To make it easier to reset your password, you should confirm your BlackBerry ID. If you use a phone number as your BlackBerry ID, you can receive a text message to verify your BlackBerry ID.