USSD can be used for different types of services. USSD interactivity is not limited to choosing from menu. USSD services can include search or other kinds of input from users. For instance in MTS Russia service *111#, weather information is given for a particular city which can be chosen from an alphabetical list or by typing in the city’s area code. Chat is another example requiring real-time interactivity.

1. Customer Care Services

The most used USSD service in this category is balance inquiry. Other uses include:

• Change of the calling plan
• Subscription to additional services (for instance, to subscribe to Mobile Email of Singaporean operator “Telkomsel” one has to dial *969# and select a registration menu)
• Top Up the Balance (using scratch cards or bank transfers, even in roaming)
• Payments to somebody else’s phone account (for instance, in MTS portal *111#)
• Collect calls