A2P 10DLC Registration in HighLevel

Updated: February 6, 2026  | 
Author: Bill Stilwell

This post covers what A2P 10DLC is, why carriers require it, what happens without registration, how to complete brand and campaign registration in HighLevel, common registration mistakes that cause rejection, and how agencies should handle registration across multiple client sub-accounts.

Reading time: about 6 minutes.

What Is A2P 10DLC?

A2P stands for Application-to-Person. 10DLC stands for 10-Digit Long Code – the standard local 10-digit phone numbers used for business SMS (as opposed to short codes, which are 5 to 6 digits).

Together, A2P 10DLC describes the system for registering businesses that send SMS from applications to people on standard 10-digit US phone numbers.

The A2P 10DLC system is administered by The Campaign Registry (TCR), a third-party organization that manages brand and campaign registrations on behalf of the major US carriers. When a business registers, TCR validates the brand information and communicates the registration status to carriers.

Registered brands and campaigns receive higher trust scores from carrier filtering systems – meaning their messages are less likely to be filtered as potential spam.

Why Is It Required?

US carriers implemented A2P 10DLC requirements to combat the surge in SMS spam and fraud that followed the growth of business SMS sending. Before A2P 10DLC, any application could send messages from a standard 10-digit number with no accountability – which was heavily exploited for spam and scam messages.

The registration system creates a chain of accountability: a business registers with TCR, provides verified business information, describes their SMS use cases, and agrees to carrier terms of service for commercial messaging. Registered businesses are identifiable.

Unregistered senders face significantly higher filtering rates – a technical enforcement mechanism that makes unregistered business SMS increasingly unreliable.

For legitimate businesses, A2P 10DLC is a compliance requirement – not optional, but also not punitive for businesses operating legitimately. The registration process is straightforward for a real business with an EIN, a website, and clear SMS use cases.

What Happens Without Registration

Without completed A2P 10DLC registration, SMS messages sent from HighLevel’s LC Phone system to US recipients are subject to carrier filtering at rates that effectively make bulk SMS unreliable. Messages that appear to send successfully in HighLevel may be silently blocked before reaching the recipient’s phone.

The filtering is not universal – some messages still get through. But the rate of delivery for unregistered sending is significantly degraded compared to registered sending.

Automated follow-up sequences that depend on SMS for engagement fail silently. Appointment reminders may not reach customers.

Review request messages may not deliver.

The business may not notice immediately – HighLevel’s sending logs show messages as sent. The delivery failures only become apparent when response rates are lower than expected or when customers mention they never received a message the system shows as delivered.

Brand Registration

Brand registration is the first step – registering the business entity. The information required includes: the legal business name (exactly as filed with the IRS or state), the business EIN (Employer Identification Number) for US businesses, the business address, the business website URL, the industry type, and the business type (LLC, Corporation, Sole Proprietor, etc.).

Accuracy matters more than completeness for brand registration. The legal business name and EIN must match the IRS records – inconsistencies between the registered name and the EIN filing cause rejection.

The website URL should be operational and clearly represent the business. An inoperative URL or a URL that does not match the business description can cause brand rejection.

Sole proprietors who do not have an EIN can register with their personal information, but the process and timeline may differ. Check HighLevel’s current documentation for the most up-to-date guidance on sole proprietor registration.

Campaign Registration

Campaign registration describes the specific SMS use cases – what types of messages will be sent and for what purpose. A campaign is not the same as a marketing campaign – it is a category description of SMS communication type.

Common campaign types include: customer care, account notifications, marketing, appointment reminders, and 2-factor authentication.

For most HighLevel sub-accounts, at minimum two campaign registrations are relevant: one for automated follow-up and nurture sequences (typically registered under Marketing or Mixed Use) and one for appointment reminders and operational messages (typically registered under Appointment Reminders or Transactional). Some businesses register separate campaigns for distinct message types.

Each campaign registration requires: a campaign description, a minimum of two sample messages that accurately represent what will be sent, confirmation of opt-in and opt-out mechanisms, and confirmation of compliance with carrier messaging policies.

Sample Messages

Sample messages are the examples provided during campaign registration that represent the actual messages that will be sent. Carriers review sample messages as part of campaign approval.

Sample messages that do not match the actual messages sent – either in tone, purpose, or compliance elements – can result in campaign rejection or filtering after approval.

Good sample messages: include the business name, reflect the actual message content that will be sent, include the required opt-out language for marketing messages (Reply STOP to opt out).

They are specific rather than generic.

For example: “Johnson Roofing: Hi [Name], thanks for your inquiry. When is a good time to discuss your roofing project?

Reply STOP to opt out.” is a much stronger sample than “Hi, we’ll be in touch soon.”

Do not submit placeholder sample messages like “Sample message here” or overly generic messages. Generic samples that do not accurately represent the business’s actual messaging increase the likelihood of rejection or carrier filtering after approval.

Processing Time and Timing

Brand registration processing typically takes a few business days. Campaign registration can take from a few days to several weeks – processing time varies based on TCR and carrier review queue volumes.

The timeline is not within HighLevel’s control; it is determined by the carrier and TCR review processes.

This processing time is the primary reason to start A2P registration at the beginning of a sub-account setup – not when SMS campaigns are ready to launch. A new account that starts registration on setup day may have approval in 1 to 3 weeks.

An account that waits until the day before a campaign launch has unregistered SMS for the entire campaign.

For agencies, build A2P registration into the onboarding checklist as one of the first steps completed after sub-account creation. The registration is initiated during setup; approval arrives before campaigns are ready to go live if the timing is right.

Common Causes of Rejection

Brand registration is most commonly rejected for: business name not matching EIN records, inoperative or mismatched website URL, missing or incorrect EIN, sole proprietor registering without appropriate personal information, or incomplete business information.

Campaign registration is most commonly rejected for: vague or inaccurate use case description, missing opt-out language in sample messages, sample messages that do not match the declared use case, missing business name in sample messages, or use case that violates carrier content policies (financial services, cannabis, firearms, and certain other categories have specific restrictions).

When registration is rejected, HighLevel’s registration interface shows the rejection reason. Address the specific reason, correct the information, and resubmit.

Most rejections are fixable – they are not permanent bans but requests to provide more accurate or complete information.

A2P Registration for Agencies

A2P 10DLC registration is per sub-account – it is tied to the specific phone number and the specific business using it. Each client sub-account requires its own brand and campaign registration using that client’s business information: the client’s legal business name, the client’s EIN, the client’s website URL.

Agencies cannot complete A2P registration for clients using the agency’s own business information. The registered brand must match the actual business sending the SMS.

An SMS that appears to come from Johnson Plumbing needs to be registered under Johnson Plumbing’s brand information – not under the agency’s brand.

For agencies, this means gathering the required business information from each new client during onboarding. A client onboarding form or checklist that collects legal business name, EIN, website URL, and business type makes the A2P registration step straightforward.

Build the information collection into the onboarding process and initiate registration for each client immediately upon gathering the information.

Opt-Out Requirements

All commercial and marketing SMS messages sent to US recipients must include an opt-out mechanism – typically the instruction “Reply STOP to unsubscribe” or similar language. This is both a carrier requirement for A2P 10DLC registered campaigns and a legal requirement under TCPA (Telephone Consumer Protection Act).

HighLevel’s SMS templates include opt-out language by default in compliant templates. When building custom SMS workflow actions or campaign messages, verify that opt-out language is included in marketing and promotional messages.

Transactional messages (appointment confirmations, order notifications) have different opt-out requirements than marketing messages.

When a contact replies STOP to an SMS sent from a HighLevel LC Phone number, HighLevel automatically updates that contact’s SMS DND (Do Not Disturb) status – preventing future automated SMS from reaching them. This automatic DND update handles the opt-out processing without any manual action required.

Key Definitions

Who Is This For?

How to Complete A2P 10DLC Registration

Step 1: Navigate to Phone Numbers in Settings

Settings, then Phone Numbers. Find the A2P registration section or prompt.

Step 2: Gather required brand information

Before starting, have on hand: the legal business name (exactly as filed), EIN, business address, website URL, industry type, and business entity type.

Step 3: Submit brand registration

Complete the brand registration form with the business information. Submit. Processing takes a few business days.

Step 4: Check brand approval status

Monitor the registration status in HighLevel. If rejected, review the rejection reason, correct the issue, and resubmit.

Step 5: Prepare campaign sample messages

Write 2 to 4 actual sample messages per campaign type – real messages that will be sent, including the business name and opt-out language. Do not use generic placeholders.

Step 6: Submit campaign registration

After brand approval, submit campaign registration for each SMS use case. Provide accurate use case descriptions and the prepared sample messages.

Step 7: Wait for campaign approval

Campaign processing varies. Check status periodically.

Do not launch SMS automations before approval is confirmed.

Step 8: Verify before launching SMS campaigns

Confirm both brand and campaign status show as approved before activating any SMS automation workflows.

Step 9: Ensure opt-out language is in all marketing SMS

Review all SMS workflow actions and templates. Confirm marketing and promotional messages include “Reply STOP to unsubscribe” or equivalent opt-out language.

How Does It Connect to HighLevel?

• LC Phone: A2P 10DLC registration is specifically for LC Phone numbers. The registration covers the 10-digit local numbers provisioned in Phone Numbers settings. Toll-free numbers and short codes have different registration requirements.
• Two-Way SMS: Two-Way SMS functionality depends on A2P registration for reliable delivery. Unregistered numbers have reduced throughput and higher filtering rates for A2P SMS.
• SMS Marketing Automation: All automated SMS sends through SMS Marketing Automation workflows use the registered LC Phone number. A2P registration is the prerequisite for reliable automation delivery.
• Appointment Reminders: Appointment Reminders sent via SMS require A2P registration. Reminder SMS is one of the specific campaign types that should be registered separately if it represents a distinct use case.
• Sub-Account Settings: A2P registration is initiated and managed through sub-account Settings, then Phone Numbers. It is one of the essential setup steps in the initial sub-account configuration checklist.

Common Questions

What is A2P 10DLC in HighLevel?

The US carrier-mandated registration system for business SMS from standard 10-digit phone numbers. Required for reliable SMS delivery through HighLevel’s LC Phone system.

Why is A2P 10DLC registration required?

US carriers require it to combat SMS spam. Registered businesses receive higher carrier trust scores; unregistered sending faces significant filtering.

For legitimate businesses, registration is a compliance formality – not a burden.

What happens if I don’t complete A2P 10DLC registration in HighLevel?

SMS messages are filtered at high rates by US carriers. Automated follow-up, appointment reminders, and review requests may not reach recipients even though HighLevel shows them as sent.

Where do I complete A2P 10DLC registration in HighLevel?

Settings, then Phone Numbers. Brand registration first, then campaign registration after brand approval.

How long does A2P 10DLC registration take in HighLevel?

Brand: a few business days. Campaign: days to several weeks.

Start during initial setup to ensure approval before campaigns launch.

Do I need to complete A2P 10DLC registration for every HighLevel sub-account?

Yes. Per sub-account, per phone number, using each client’s business information. One registration does not cover multiple sub-accounts.

To Wrap It Up

A2P 10DLC registration is the unsexy foundational requirement that determines whether the platform’s most valuable features – automated SMS follow-up, appointment reminders, review requests – actually work. It is not complicated for legitimate businesses.

It requires accurate business information, an EIN, a working website, and real sample messages. The process takes minutes to submit and days to weeks to be approved.

The operational discipline required is starting early. A2P registration that is initiated on day one of sub-account setup arrives before the first SMS campaign is ready to launch.

A2P registration that is initiated the week before a campaign launch means sending on an unregistered number – with the filtering and delivery failures that come with it.

For agencies, the discipline is building client information collection into the onboarding process and initiating registration immediately. Every client sub-account that sends SMS to US numbers needs A2P registration using that client’s specific business information.

Treating it as a standard onboarding step rather than an afterthought ensures every client’s SMS infrastructure is compliant from day one.