What is A2P 10DLC?
A2P 10DLC (Application-to-Person 10-Digit Long Code) is a US carrier-mandated registration system for businesses that send text messages to customers using standard 10-digit phone numbers. If you send any SMS through Regal — including automated campaign messages, AI-generated outbound messages, or messages sent by human agents in conversations — A2P 10DLC registration is required. Unregistered messages will not be delivered.
"A2P" refers to the nature of the messaging: a business (like you) using an application (like Regal) sending messages to individual consumers. "10DLC" refers to the standard 10-digit phone numbers used to send those messages. Carriers introduced this system to reduce spam and improve deliverability for legitimate businesses, and registration is now mandatory across all major US carriers.
Why It Matters
Before A2P 10DLC, long code SMS was unverified and easily abused by spammers, which led carriers to aggressively filter messages sent from 10-digit numbers. A2P registration was designed to mitigate this: by verifying your business and your messaging use case, carriers can distinguish your legitimate traffic from spam and deliver it reliably. Registered senders benefit from better deliverability, higher sending throughput, and lower risk of filtering.
Registration Doesn't Guarantee Delivery
A2P 10DLC registration is necessary but not sufficient for reliable message delivery. Carriers still actively filter messages from registered senders if the content violates their guidelines. Common reasons registered messages get filtered include:
- Including links that appear suspicious or go through URL shorteners (e.g., bit.ly)
- Referencing prohibited content categories such as cannabis, firearms, gambling, or payday loans
- Using language or formatting that resembles spam (excessive capitalization, misleading subject lines, pressure tactics)
- Mismatching your message content with your registered campaign use case
- High opt-out rates due to poor opt-in practices or messaging contacts who haven't consented or engaged with your brand in a long time
Registration tells carriers who you are and what you're sending, but it doesn't give you a free pass. Think of it as a license to operate, not a guarantee of delivery. Following carrier content guidelines and messaging best practices is what keeps your messages reaching recipients consistently.
How to Register for A2P in Regal
Registration happens in two steps: Brand registration and Campaign registration.
Brand registration verifies your business identity. You'll need to fill out your business profile in the Regal app and wait for approval. This step establishes who you are with the carriers.
Campaign registration verifies your messaging use case — for example, marketing/promotional messages, appointment reminders, or transactional notifications. Carriers review campaigns to confirm the messaging is legitimate and matches the registered use case. Campaign-level registration is handled with the help of the Regal team. Reach out to your Customer Success Manager or email support@regal.ai to get started. Have your EIN ready to speed up the process.
How Long Does A2P Registration Take?
Brand registration typically completes within a few minutes to 24 hours, assuming the information you provide matches your business records. Any discrepancies can trigger a manual review that takes up to 7 days.
Campaign registration is subject to carrier vetting and generally takes around 7-14 business days for standard use cases. Plan for this lead time before launching any SMS campaigns — messages sent before registration is approved will not be delivered.
FAQs
- Is A2P 10DLC registration really required? Yes — and it applies to all SMS sent through Regal, including messages sent by human agents in conversations, not just automated or AI-generated messages. Carriers treat all messages sent from a Regal 10DLC number as application-to-person traffic regardless of who is actually typing the message. Unregistered messages will not be delivered. There are no workarounds.
- Can I send messages while registration is in progress? No. Messages sent before your campaign is approved will be filtered by carriers. Make sure to account for the 7-business-day vetting window before any planned SMS launches.
- What happens if my registration is rejected? Campaign rejections are usually due to incomplete information, a mismatch between your registered use case and actual message content, or missing opt-in language. Your CSM can help you troubleshoot and resubmit.
- Does A2P 10DLC affect my call campaigns? No. A2P 10DLC is specific to SMS and MMS messaging. It has no impact on your voice calling campaigns in Regal.