What is P2P and A2P Messaging?


Jessica Murray




Attributes (per number)

Common use cases

P2P - Conversational Person to Person

Typically, this is the conventional conversational two-way SMS or MMS messaging between individuals.

From CTIA best practices: “Person-to-Person (P2P) generally describes the low-volume exchange of wireless messages between end users... the concept of consistent with typical human operation defines P2P traffic to distinguish P2P from A2P traffic.”

  • 15-60 messages/minute
  • 1,000 messages/day
  • 100 unique recipients
  • Close to 1:1 inbound messages to outbound messages
  • 25 repetitive messages
  • Support over SMS
  • Chat Bots
  • Over-the-top (OTT) tel-co application
  • Private Phone Numbers

A2P - Automated message to Person

One-way SMS to which recipients are not expected to reply. Typically this represents high volume messaging between businesses and individuals.

Some common examples are a logistics company sending delivery statuses and notifications, a dentist’s office sending one-way alerts and reminders, or a financial institution sending PIN codes to individuals either using short codes or long codes.

From CTIA best practices: “A2P traffic is all messaging that falls outside the definition of P2P (i.e., traffic that is not consistent with typical human operation).

  • Bound only by account permissions/rate limits
  • Sent with a toll-free phone number. Long Code A2P is currently in Limited Availability.
  • Typically much higher ratio of outbound messages vs inbound
  • Appointment Reminders
  • Shipping & Order Alerts
  • Outbound Mass Communications

The major difference between the current P2P service that Bandwidth offers today on US and Canadian local 10-digit phone numbers and the A2P Messaging service using Toll-Free numbers (and soon on Long Codes) is:

  • A2P formally allows TCPA compliant and opted-in use cases for many application-to-person use cases such as alerts, PIN codes, requested marketing, and automated, high-volume interactions between business/government and consumers.
  • The 1 SMS/number/second message limits imposed in the guidelines for P2P messaging don't apply to A2P messaging services.
  • The use of a A2P text messaging service requires formal approval by Bandwidth (and potentially carriers depending on the use case and company generating the outbound traffic).  
  • The A2P service is priced differently than P2P messaging services.

If your use case requires A2P messaging, please see our toll-free A2P use case best practices.

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