What is A2P and P2P Messaging?
What is A2P and P2P Messaging?
Section titled “What is A2P and P2P Messaging?”SMS messaging traffic is broadly divided into two categories: A2P and P2P. Understanding the difference matters because each is subject to different carrier rules, regulatory requirements, and potential filtering.
A2P Messaging (Application-to-Person)
Section titled “A2P Messaging (Application-to-Person)”A2P messaging refers to messages that a person receives from an application or automated system. The message originates from software, not from another human typing on a phone.
Common A2P use cases include:
- One-time passwords (OTP) and two-factor authentication codes
- Appointment reminders
- Account notifications and alerts
- Chat bots and virtual assistants
- Marketing and promotional messages
- Delivery status updates
A2P messages are subject to local country regulations. In the United States, A2P traffic sent over 10-digit long code numbers requires registration with The Campaign Registry (TCR) under the A2P 10DLC framework. Non-compliance can result in message filtering or blocking by US carriers.
P2P Messaging (Person-to-Person)
Section titled “P2P Messaging (Person-to-Person)”P2P messaging is a two-way conversation between two human beings, each using their phone to send messages directly. No application is mediating the exchange.
Under telecom regulations in Canada and the United States, P2P messaging has a narrow definition. Any application-mediated messaging — even if it involves a human on one end — is treated as A2P, not P2P.
Why the Distinction Matters
Section titled “Why the Distinction Matters”| Aspect | A2P | P2P |
|---|---|---|
| Carrier filtering | Subject to filtering; registration reduces risk | Generally not filtered |
| Registration required (US) | Yes, for long code A2P (10DLC) | No |
| Volume | Can be high-volume / bulk | Typically low-volume conversational |
| Throughput limits | Apply based on registration and trust score | Not applicable |