The serial number of the terminal will be used to associate or transfer a terminal from one profit center to another. That's where you can find this serial number (or identifier).
The serial number can be easily found in the Cashless Sync application. Just open the application and scroll down to the bottom.
In addition to Cashless Sync, the serial number is indicated on a label affixed to the back of the terminal
In addition to Cashless Sync, the serial number is located under the terminal's battery. You will need to remove the case and the battery to see it.
There may be a serial number on the battery itself, that is not the one of the terminal.