I confirm that serial number are sent to me when I received the MITEL products.
It is a paper called packing note where I have quantities of stuff and list of part number and corresponding MAC and serial numbers. This list is called "Manifest report by Carton delivery...
I'm in EMEA zone.
Following what TheMitelGuy says, if serial is not hard coded you'll have to have this kind of list and OCR it !
If you can't, your best way would be to have an infrared scan in order to scan all the telephone one by one...
I guess if you have to install lots of telephone, you'll have to take some time for that...
Sorry chaps
Now, it's about French users too !!!