A2P SMS
Application-to-Person messaging — automated or bulk SMS sent from a business platform to customers, as opposed to person-to-person texting.
A2P SMS (Application-to-Person) refers to text messages sent from a software platform or business system to a person's mobile phone. Unlike P2P (Person-to-Person) messaging — two people texting each other directly — A2P involves a sending application: marketing software, appointment reminders, appointment confirmation systems, alert platforms, or business phone systems.
Examples of A2P SMS include: appointment reminders from a dental office, shipping notifications from an e-commerce store, two-factor authentication codes from a bank, and missed call auto-reply messages from a business phone system. Even conversational business texting — where a customer texts a business and an agent replies — is classified as A2P if the messages flow through a business platform.
In the U.S., A2P SMS is regulated through the 10DLC (10-digit long code) registration framework administered by The Campaign Registry. Businesses must register their brand and messaging campaigns before sending A2P messages through standard 10-digit phone numbers. This registration verifies the sender's identity and campaign purpose, reducing spam and improving deliverability. Zonitel handles A2P 10DLC registration for all customers as part of the onboarding process.