Unstructured Supplementary Service Data (USSD) is a session based service unlike SMS, which is a store and forward service. USSD can be used by the user to send command to an application in text format. USSD acts as a trigger for the application. Currently this service is mainly being used for checking balance in financial accounts and mobile prepaid recharge. A three-digit short code *166# has been allotted to Mobile Seva for this service. USSD is more interactive as compared to SMS but nothing is stored on the phone. This can be very useful for submitting requests for a service through an interactive menu and for tracking their status.