Arduino MKR NB1500 devices purchased on TelstraDev IoT marketplace include an activated Cat-M1 SIM card (aka LTE-M). The Board DOES accept NB-IoT SIMs, however this connectivity is NOT currently included in the TelstraDev product bundle. For more information on Telstra's LPWAN IoT connectivity options and coverage maps, see our IoT website: https://www.telstra.com.au/business-enterprise/about-enterprise/our-network/iot-coverage-map
With that included Cat-M1 SIM, you have a 60MB data allowance for 180 days (i.e 6 months) from the date of purchase, included in the Arduino purchase price.
To check your usage, you can use the Connected Things API available on our portal: https://dev.telstra.com/content/connected-things-api
After 6 months, or exceed 60MB data usage (whichever comes first), the SIM will be deactivated. If you wish to continue using the Cat-M1 IoT Network, you can order a data SIM plan from the Telstra website: https://www.telstra.com.au/small-business/internet-of-things/data-sim-plans#non-shared
To share ideas on your work with the Arduino and IoT connectivity with other Devs, post on our Community Forum: https://dev.telstra.com/content/get-connected-all-things-iot
If you've got a question on the Arduino MKR NB 1500 connectivity and Connected Things API, check out our FAQ first; https://dev.telstra.com/support/frequently-asked-questions, or join the community with our good friends at Arduino; https://forum.arduino.cc/index.php?board=107.0.