If you would like to know how much data a particular SIM has utilized, you can do so with the following steps, also listed here
- First, log into the User Console
- Click the drop down in the top left and select SIM Management
- Select the box next to the SIM in question, and select Details
- Select Historical Charts to view both the upload and download data usage for that particular SIM
This data within the bar chart can be displayed either monthly, daily, or hourly or you can specify a day within the last 18 months to display.