Data banking means you can roll over and save any unused data. Occom Mobile offers up to 500GB of data storage. For example, if you’re on the 10 GB plan and you only use 3 GB for the month, next month you’ll have 10 GB plus the 7 GB left over from the previous month, for a total of 17 GB. So long as you pay your bill on time, and do not downgrade your plan, your banked data will never expire.