The label on the Toradex modules has both the Serial number as text ( last 3 bytes of the MAC)
and a QR code.
Although the QR code has a longer number.
From what i can see, the last 9 digits are the serial number (and MAC) of the device
e.g. 0020120006897455
06897455 = S/N and last 3bytes of the MAC.
What does the first part of the number (00201200) represent?
Jamie.