Definitions
Application-to-Person (A2P): A software application used for the sending of messages, typically from a business for commercial purpose, to a person (e.g., appointment reminders, marketing, e-commerce, OTP/2FA notifications, or emergency alerts). Communication can be 1-way or 2-way (P2A when the person replies).
Person-to-Person (P2P): Two people (e.g., friends, family, or colleagues) messaging each other with purely personal content and no commercial purpose, using mobile phones typically equipped with SIM or eSIM cards. Communication is generally expected to have a nearly 1:1 message ratio.
Registration differences
A2P messaging is increasingly subject to heightened regulations worldwide due to the propensity and high risk of fraud and scams. Regulations requiring registration vary significantly by country, such as:
National Sender ID Registries and associated regulations (e.g., Australia, Finland, Ireland, Italy, Singapore, and Spain)
Industry-wide Codes of Conduct (e.g., Belgium and France)
Local Carrier Requirements (i.e., countries where neither of the above apply, requiring compliance with individual carrier rules.
Categorization differences
In a Communications Platform-as-a-Service (CPaaS) environment, real-time, 2-way business messages are often application-based, but typed by a person, such as:
A doctor's front office sending a patient an appointment reminder
A hotel reception messaging a guest about their upcoming stay
Customer support helping an end user troubleshoot an issue
In the United States, this is categorized as conversational business messaging (A2P) and is heavily regulated. However, other countries treat this communication differently:
Light Regulation/Simulated P2P: Some countries categorize this 2-way, free-text conversational communication as P2P, which benefits from different regulatory treatment.
P2P Excluded from CPaaS: Other countries strictly define P2P as messages sent only between two mobile phones, meaning this type of communication cannot be offered in a CPaaS environment.
For specific details on regulations in each country, please see our Global Messaging section.