A device using the Scandit SDK version 6. x for capturing data is registered as an active device once the scanner has started and the first frame has been processed.
It remains an active device for the given billing period of the subscription and if there is usage within the subsequent billing period, it will remain counted as an active device.
Setting the license key or creating a data capture context doesn't lead to a registration of a new device and it's therefore save to do this at application start, irrespective of the user is going to use it or not.
The device itself is identified by a unique device ID created by the Scandit SDK at first use. The device is not related to hardware identifier (e.g. it's not the IMEI number).