Twilio Programmable SMS Text Messaging generally falls within one of two categories: A2P and P2P messaging. Read on to find out the differences, and which is right for you.
A2P, or application-to-person messaging, is any kind of traffic in which a person is receiving messages from an application. A2P messaging includes (but is not limited to) marketing messages, appointment reminders, chat bots or virtual assistants, notifications, and one-time passwords (OTPs) or PIN codes.
Carriers in the United States and Canada have a strict interpretation of A2P, and consider all messaging that passes through Twilio (or other messaging application platforms) to be A2P.
A2P messages can be subject to local country regulations (e.g. France and India). These restrictions can have delivery implications that customers should be aware of, such as message filtering by recipient carriers or delayed message delivery.
P2P, or person-to-person messaging, is generally defined as a two-way (back and forth) messaging conversation between two humans. This could be messages between friends on mobile phones, or messages connecting two people using Twilio's REST API as a conduit.
In the United States and Canada, P2P messaging is defined very narrowly by telecom regulations, and does not include any application-mediated messaging. All Twilio messaging is considered A2P in the US and Canada.
In other countries, the P2P messaging categorization may cover some application-mediated communications, such as texting between a customer and a support agent (for example using Twilio Flex), conversations between two users via a proxy number, or messages to and from a delivery or rideshare driver.
What numbers or senders should I use for my type of messaging?
United States and Canada carriers consider all traffic passing through Twilio to be A2P. You have several options for how to send this traffic; for an overview, please see Comparison of SMS messaging in the US and Canada for long codes, short codes, and toll-free phone numbers
If your use case involves P2P messaging, you should use Twilio numbers from the same country as your recipients to ensure two-way SMS functionality.
If a country has specific rules surronding P2P versus A2P traffic, we will share those details on our SMS Guidelines page for that country.