When I first got my BlackBerry Bold 9700 from T-Mobile it did not have their Mobile Backup service where you could automatically, wirelessly backup and restore your contacts. See the image below…

The factory default BlackBerry OS that my 9700 came with was 5.0.0.330. Over the weekend I upgraded to the leaked OS 5.0.0.405 and started to look around to see what was different. I found a new menu item in Options called Mobile Backup so I checked it out and it looks like the new OS either has the service or T-Mobile pushed it out and I just didn’t realize it.

After accepting the terms and activating the Mobile Backup service it did an initial synchronization of my contacts. I logged on to My T-Mobile and sure enough, there were my contacts pretty much fully synced. When you log in to the My T-Mobile site check the right side of the web page for a box titled “Connect With MobileLife”.

The Mobile Backup service appears to only sync primary info like first and last name, mobile or work phone numbers and the primary email address. Not all the fields in the BlackBerry Address Book get synced to your My T-Mobile account, but you can edit your online contacts to add more info like multiple work numbers, multiple home numbers, mobile phone numbers, pager, fax, web page URL, instant messenger usernames and more.

After the initial sync the Mobile Backup service will automatically backup any changes you make in your BlackBerry Address Book to your My T-Mobile MobileLife account. This works the other way to, any changes you make to your MobileLife account can sync to your BlackBerry.

If you’re a T-Mobile customer with a BlackBerry Bold 9700 check if you have this service in Options > Mobile Backup, try it out and let me know what you think in the comments!