Serial number on new XPS 17.

I need to send the serial number to my insurance agent for my new XPS 17.  All I can find is the two codes that Dell puts on there.  I think it is Express code and Service Tag code.  I looked under the battery but there is nothing there.  I was really hoping there is something more permanent that a little sticker from Dell.

Any help on what is considered the serial number would be greatly appreciated.