What is A2P? Featured in our MaaP solution, A2P generally refers to functionality that allows an application (e.g., a web app) to send a message to one, or many simultaneous, mobile phones. Common use cases of A2P are alerts, notification, and branded marketing messages, such as flight alerts. In all the cases, communication is initiated from a business application, and not an individual’s mobile phone, as is the case with P2P SMS.