METHOD 2: Identification through assignment of a unique Type Allocation Code (TAC)
Each device has a number known as the IMEI (International Mobile Equipment Identity), and the TAC is the first eight digits of the IMEI (see picture below). A dedicated TAC can be allocated by a GSMA reporting bodies, depending on your region of deployment.
This TAC must be unique to YOUR device and YOUR company. It cannot be a TAC range shared with any other company or your module supplier. Some devices can share an IMEI TAC across a family of products that have similar characteristics. AT&T will accept a family TAC or a unique TAC assignment to comply with ODIS.
Additionally, the device manufacturer must communicate the TAC assignment to their chosen module provider as this value typically needs to be assigned to the module at the time of manufacture.