If you would like to check how much data you have used, most handsets will allow you to view and manage your data usage.
Click the manufacturer links for instructions:
Apple iOS: Apple Support
Android: Android Support
BlackBerry: BlackBerry Support (refer to Smartphones > User Guide)
Why Is The Data Usage On My Device Different Than My Bill?
Your handset may measure data differently than mobile operators. If you have a problem with your bill, or wish to learn more about data usage, please contact your account admin.
Note: Truphone data usage in and out of bundle is rounded to the nearest 1KB.