Short codes, or short numbers, are short digit sequences, significantly shorter than telephone numbers, that are used to address messages in the Multimedia Messaging System (MMS) and short message service (SMS) systems of mobile network operators. In addition to messaging, they may be used in abbreviated dialing.
Short codes are designed to be easier to read and remember than telephone numbers. Short codes are unique to each operator at the technological level. Even so, providers generally have agreements to avoid overlaps. In some countries, such as the United States, some classes of numbers are inter-operator (U.S. inter-operator numbers are called common short codes).
Short codes are widely used for value-added services such as charity donations, mobile services, ordering ringtones, and television program voting. Messages sent to a short code can be billed at a higher rate than a standard SMS and may even subscribe a customer to a recurring monthly service that will be added to the customer’s mobile phone bill until the user texts, for example, the word “STOP” to terminate the service.
A long number also known as a virtual mobile number, dedicated phone number or long code, is a reception mechanism used by businesses to receive SMS messages and voice calls. As well as being internationally available, long numbers enable businesses to have their own number, rather than short codes which are generally shared across a lot of brands. Long numbers allows a wide range of industries to generate large amounts of mobile-originated SMS from the subscribers, such as wireless application service providers, mobile virtual network operators, mobile virtual network enablers, SMS aggregators, e-sellers, advertising agencies, media channels and mobile infrastructure providers.