What is a Short Code?

A short code is essentially a special, shortened phone number that's used to send and receive SMS messages in high volumes. 

Short codes are pre-approved by carriers, and there are different types of short codes for different regions. This pre-approval means that your messages are far less likely to be marked as spam by that region's carriers - which makes short codes ideal for sending large-volume broadcasts, or important messages that you need to get through quickly.