An SMS long code is a 10-digit number used to send and receive one-to-one or one-to-a-small-group text messages, faxes and calls. An SMS short code is 5-6 digits and can only send and receive texts. Long codes transmit one message per second, while short codes can send 40 messages per second and are well suited for mass notification, alerts and marketing. Short codes were devised with organizations in mind, and while well supported by carriers, the regulations for short code users are more detailed than for long code users. Short codes are also more costly and generally used for high-volume text notifications.