If you subscribe to Smart Always ON internet surfing package, you check the status on how much data you already consumed or the KB’s left on the time you stop browsing via SMS and via Web . To inquire your remaining data balance on you Smart Bro / mobile internet you can send the code via SMS or login to your Smart account via Web.
Smart Always ON Balance Inquiry
Just text BAL to 2200
You will receive a SMS from Smart telling your remaining volume of data.
All you need to do is login to your Smart Account then select Smart Bro prepaid account, select Balance Inquiry under Inquiries tab.
Source: Smart Always ON