Application-to-Person (A2P) messaging is text messaging that a business or organization sends through software, as opposed to personal texting from one phone to another. Messages may be fully automated or typed by an agent in a business platform. Appointment reminders, delivery notices, one-time passcodes, fraud alerts, two-way customer service texts and marketing offers are all A2P. Because A2P channels are also abused for spam, carriers apply their own controls to them, including registration, content checks and filtering, on top of whatever laws apply where you send.
At a glance
- Covers business messages sent from software, platforms and cloud phone systems over SMS and MMS, and in some cases richer messaging channels.
- Carriers expect A2P traffic to use approved channels; in the US that means 10DLC, verified toll-free numbers or short codes.
- Unregistered or poorly matched traffic is more likely to be filtered, throttled or blocked.
- Consent and opt-out rules apply and vary by country; in the US the TCPA and carrier messaging rules are the usual starting point.
What problem it solves
Customers often read texts quickly, which makes messaging a natural channel for time-sensitive alerts and conversations. Sending those messages at scale from ordinary phones doesn’t work, and sending them through the networks without identifying who is sending invites abuse.
A2P messaging gives businesses a sanctioned way to send texts from applications, with the throughput and delivery reporting they need. For carriers and recipients, the A2P framework adds accountability: senders are identified, use cases are declared, and abusive traffic can be traced and stopped. For a buyer, understanding A2P explains why a texting project now involves registrations, approvals and consent records rather than just an API key.
How it works
Sending platform. Messages originate in a communications platform as a service (CPaaS), a contact center, a marketing tool or a cloud phone system. The platform sends them to a messaging aggregator or carrier, which delivers them to mobile networks.
Sender type. The number or ID you send from determines the rules. In the US, local 10-digit numbers used for business messaging must generally be registered under 10DLC; toll-free numbers go through a verification process; short codes (five- or six-digit numbers) are applied for and approved per program. Elsewhere, alphanumeric sender IDs and sender registration schemes are common.
Registration and vetting. Depending on the channel, you register your business identity and describe each messaging use case, with sample messages and how recipients opt in.
Filtering. Carriers and their partners scan traffic for spam patterns, mismatched content and complaints. Messages that fail checks can be delayed, filtered or blocked, sometimes without a clear error to the sender.
Consent and opt-out. Recipients must be able to opt out, usually by replying STOP, and senders need records of how consent was obtained. The specifics depend on the law and the carrier rules where recipients are.
Our Communications Platform as a Service page covers how to compare messaging providers.
When it matters for buyers
- Launching appointment reminders, alerts or two-factor codes. Pick the right number type before you build.
- Adding texting to a cloud phone system or contact center. Business texting from those platforms is usually A2P and needs registration.
- Delivery problems. Sudden drops in delivery often trace back to registration, content or volume issues.
- Marketing by text. Consent, opt-out and quiet-hours rules are stricter; involve counsel.
- Expanding to other countries. Sender ID rules and registration requirements differ by country.
Questions to ask vendors
- Which sender types do you support (10DLC, toll-free, short code, alphanumeric), and which fits our use case and volume?
- Who handles registration and verification, how long does it take, and what fees pass through from carriers or registries?
- What throughput limits apply to each sender type and registration tier?
- What delivery reporting and error codes can we see when messages are filtered?
- How do you manage opt-outs and consent records?
- Do you support messaging in the other countries where we have customers?
How it differs from 10DLC
A2P is the category: any business message sent by an application. 10DLC is one US channel for carrying it, using ordinary 10-digit local numbers that have been registered for business use. A US business sending A2P texts might use 10DLC for conversational and moderate-volume traffic, a verified toll-free number for broader notifications, and a short code for very high volumes, each with its own registration path.