Application-To-Person (A2P) SMS

A2P is delivered through Mobile SMS carriers/gateways. While SMS reached its popularity as a person-to-person (P2P) messaging, another type of SMS is growing fast: application-to-person (A2P) messaging. A2P is a type of SMS sent from a subscriber to an application (MO) or sent from an application to a subscriber. It is commonly used by businesses, such as banks, to send SMS messages from their systems to their customers.

In the US, carriers have traditionally preferred that A2P messages must be sent using a short code rather than a standard long code.However, recently multiple US carriers, including Verizon have announced plans to officially support A2P messages over long codes. In specific markets A2P messages can be sent with a dynamic 11 character sender ID; however, short codes are used for OPTOUT commands.