P2P vs A2P Messaging
P2P vs A2P Messaging
US carriers classify text messages into two categories. Understanding the distinction is critical for deliverability and compliance.
Definitions
Person-to-Person (P2P)
Conversational messages between two individuals. One person texts another, and they reply. No automation, no bulk sending, no business workflows.
Example: You text a friend to confirm dinner plans.
Application-to-Person (A2P)
Messages sent by a business or application to a person. This includes automated messages, bulk campaigns, notifications, marketing texts, and any message sent through a platform like JustCall.
Example: An appointment reminder sent from your scheduling software.
Why It Matters
All business messaging through JustCall is classified as A2P — even if an agent manually types a one-to-one reply. Carriers classify based on the sending platform, not the content.
This means:
- Your numbers must be registered for A2P messaging (10DLC for US local numbers, toll-free verification, or short codes).
- Unregistered A2P messages are blocked by US carriers (since September 2023).
- A2P messages are subject to throughput limits based on your trust score.
- P2P throughput rates do not apply to business messaging.
Registration Requirements
| Number Type | Registration |
|---|---|
| US local (10DLC) | Brand + Campaign registration required |
| US toll-free | Toll-free verification required |
| Short code | Carrier approval required |
| International | Varies by country |