A2P SMS

Application-to-person SMS: messages sent by software (verification codes, alerts) rather than by another person.

A2P (application-to-person) traffic is what a platform sends when it texts you a verification code, a delivery alert, or a marketing message. Carriers route and price A2P differently from person-to-person texting, and many countries require sender registration for it.

Verification codes are the largest single category of A2P traffic, which is why delivery speed and reliability of these messages vary by route and carrier.