Definition · Business Texting
A2P messaging
Also known as: A2P, application-to-person messaging, A2P SMS
A2P (application-to-person) messaging is any text sent from a software application to a person's phone — appointment reminders, marketing texts, alerts, two-factor codes. It is distinct from P2P (person-to-person) texting and is subject to carrier registration and compliance rules such as 10DLC in the United States.
A2P is the category that almost all business texting falls into: a system, not a human thumb, originates the message. Because A2P traffic is automated and high-volume, carriers treat it differently from ordinary P2P texting — it must be registered (via 10DLC on local numbers, or through toll-free or short-code verification) and it is filtered against spam rules.
For a buyer, A2P framing clarifies why business texting carries compliance overhead that personal texting does not. Consent matters: under the TCPA and carrier rules, recipients generally must opt in, and marketing messages need a clear opt-out. Skipping registration or consent doesn't just risk fines — it gets messages silently blocked, which quietly destroys the ROI of a texting program.
The practical buyer questions are whether the platform handles A2P registration for you, how it manages opt-in/opt-out, and which number type (local 10DLC, toll-free, or short code) fits your volume and use case.