Key Point: Sending SMS messages from a U.S. number to a U.S. number will fail without approved A2P 10DLC registration.
What is A2P 10DLC?
A2P: Application-to-Person (meaning messages sent from a software application, rather than from one person's phone to another's).
10DLC: 10-Digit Long Code (refers to standard U.S. phone numbers).
Essentially, A2P 10DLC is a system required by U.S. mobile carriers (like Verizon, AT&T, T-Mobile) for businesses sending messages from applications using standard phone numbers.
Why is Registration Necessary?
Carrier Mandate: This registration is required by U.S. carriers and enforced by platforms like Twilio (our SMS provider) to verify legitimate business messaging and combat unwanted spam. It is not a requirement specific to the platform itself.
Message Deliverability: Without an approved registration linked to your sending phone number, carriers will block your messages to U.S. recipients.
How to Check Your Status and Initiate Registration:
Navigate to Phone System Settings:
Click on Settings in the bottom-left menu.
Under the "Communication" section (you might need to scroll down), click on Phone System.
Access the A2P 10DLC Section:
Within the Phone System settings, you will see tabs like "Phone Numbers" and "A2P 10DLC".
Click on the A2P 10DLC tab.
Check Your Current Status:
This page displays your current A2P 10DLC registration status. If you’re just getting started the blue button will say “Register Now” and if you already submitted your application It might show "Registration Failed," "Approved," "Draft," or "In Progress".
Complete the Registration Form:
A form titled "A2P 10DLC Business Registration Form" will appear.
Crucially, you must fill out this form completely and accurately. It asks for details about your business, how you plan to use SMS (your "use case"), examples of messages you'll send, how contacts opt-in, your business registration information, point of contact, etc.
Pay close attention to all required fields (marked with an asterisk *) and provide detailed information, especially for the campaign use case and sample messages.
Submit the Form:
Once the form is complete, click the Submit button at the bottom.
What Happens Next?
Your submitted information is sent to the support team.
Our team reviews the information and submits it through the official channels for carrier approval.
This process is usually concluded in 7 days but can also take 3-4 weeks, according to Twilio.
You can monitor the status on the Settings -> Phone System -> A2P 10DLC page.
Once Approved, your designated U.S. phone number(s) will be compliant, and messages to U.S. recipients should be delivered successfully. If rejected, the reason may be displayed, and you might need to re-submit with corrections.
Important Notes:
US-to-US Only: This A2P 10DLC registration is specifically required when sending SMS messages from a U.S. number to another U.S. number via the application. Sending to non-US numbers may have different requirements or none at all, depending on the destination country.
Fees: As indicated on the A2P 10DLC page, there are typically one-time setup/vetting fees, brand registration fees, and potentially small recurring monthly fees associated with maintaining this registration, which are passed down from the carriers/Twilio.