GoHighLevel
3 min read
A2P 10DLC, explained for people who just want their texts to arrive
Registration is the single biggest determinant of whether your automated US texts arrive. Here is what it is, what it involves, and why campaigns get rejected.
Quick answer
What is A2P 10DLC?
A2P 10DLC is the framework US mobile carriers use to register application-to-person text traffic sent from standard ten-digit numbers. Businesses register a brand and one or more campaigns describing their use case, and carriers assign throughput limits accordingly. Unregistered traffic is heavily filtered or blocked.
If you send automated texts to US numbers from a normal ten-digit phone number, this applies to you. It is not optional and it is not a formality.
What the letters mean
A2P — application-to-person. A message sent by software rather than typed by a human.
10DLC — ten-digit long code. An ordinary phone number, as opposed to a short code or a toll-free number.
So: automated messaging from a normal phone number. That is the category, and US carriers require it to be registered.
Why it exists
Before the framework, A2P traffic on standard numbers was indistinguishable from person-to-person texting, which made it an effective spam channel. Registration gives carriers a verified sender identity, a declared use case and an accountable business behind every automated message.
The trade for senders is real: registered traffic gets better delivery and higher throughput. Unregistered traffic gets filtered, throttled, and increasingly blocked outright.
The two things you register
A brand. Your legal business identity — registered name, tax ID, address, contact. This is verified against public records, and mismatches are the most common source of delays.
A campaign. What you actually send: the use case category, sample messages, how consent is collected, and how opt-out is handled. Carriers assign throughput based on this.
You can have several campaigns under one brand. You should, if you genuinely send different kinds of message — mixing them under one registration is a mismatch waiting to be throttled.
The Twilio A2P 10DLC documentation is the clearest public reference on how brand trust scores translate into daily message limits, regardless of which platform you send through.
Why registrations get rejected
Business details that do not match public records. The legal name and address must match your registration exactly. “Trading as” names are a frequent cause of failure.
Sample messages that do not match the declared use case. If you register for customer care and your samples are promotional, expect a rejection.
No visible consent mechanism. The form or process where people opt in must be reachable and must actually say what they are opting into. A checkbox with no text does not qualify.
A privacy policy that does not mention SMS. Carriers check. Your policy needs to describe SMS data handling and message frequency.
Missing opt-out language. Sample messages should show how recipients stop, and STOP must genuinely work everywhere in your account, not just in one workflow.
What it does not cover
Registration is about delivery, not legality. Being registered does not make it lawful to text someone who did not consent. The TCPA governs that, and it is a separate obligation with materially larger consequences.
Nor does it cover other markets. The UK and EU have PECR and GDPR; Canada has CASL; Australia has the Spam Act. Each has its own consent rules and none of them are satisfied by a US carrier registration.
This is not legal advice — confirm your obligations with your own advisor.
Practical sequence
- Get the legal business details exactly right before starting, including the tax ID
- Make sure the privacy policy covers SMS and is publicly reachable
- Make the consent mechanism visible and explicit at the point of capture
- Register the brand, then register campaigns that honestly describe what you send
- Verify opt-out works across every workflow in the account, not just the one being tested
- Then ramp volume gradually rather than switching a large campaign on at once
Step six is the one that catches people who did everything else correctly. A newly registered number sending thousands of messages on day one still looks anomalous. Delivery problems that survive a clean registration are almost always send-pattern problems — the other causes are in why your SMS is not being delivered.
Services mentioned here
Get your business texting approved before it costs you leads
A2P 10DLC is the registration system US carriers require for application-to-person messaging over standard 10-digit numbers. It involves registering your brand and each messaging campaign. Without approved registration, messages to US numbers are heavily filtered or blocked outright, so it is mandatory rather than optional for US SMS.
Make sure the messages you automate actually arrive
Automated messages fail to deliver most often because the sending domain is not authenticated with SPF, DKIM and DMARC records, because a new sending domain or number was used at high volume without warm-up, because sender reputation has been damaged by complaints, or because required carrier registration was never completed.
GoHighLevel setup, configured around how you actually sell
GoHighLevel setup is the initial configuration of an account: creating pipelines and stages, custom fields, calendars and booking rules, core workflows, forms and funnels, connecting phone numbers and email domains, completing messaging compliance registration, and integrating the platform with the other tools a business already uses.