About backing up your BBM contact list
BlackBerry Messenger provides you with a few ways to back up and restore your BBM information, which can include your contacts, profile, and group membership. By default, BBM saves a backup file of your BBM information to your smartphone when your contact list changes. However, you can save a backup file to your smartphone or media card manually at any time. You might also be able to set BBM to automatically back up and restore your contact list over the wireless network to a BBM server that is operated by or on behalf of Research In Motion or its affiliates.
It's a good idea to regularly save a backup file of your smartphone data on a computer in case your smartphone is lost, stolen, or corrupted by an unforeseen issue. For information about backing up your smartphone using BlackBerry Desktop Software, see the help in the BlackBerry Desktop Software.