Articles on: Call and SMS Management

How to Register for A2P 10DLC Text Messaging?

A2P 10DLC is a required registration process for businesses that send text messages to customers in the United States using long code numbers. It helps mobile carriers identify your business, reduce spam, and improve message delivery.


If you plan to send application-to-person messages, you must complete this registration first. Let’s learn how to register for A2P 10DLC based on your business type.

How do I Register for A2P 10DLC?


You can register for A2P 10DLC by logging in to Calilio, opening the A2P Messaging section, submitting your brand and campaign details, and completing the required verification and payment.


Step-by-step A2P 10DLC registration via Calilio


Step 1 - Access A2P Messaging via Calilio:

Log in to Calilio → go to Settings → A2P Messaging → click Get Started to begin registration.


Step 2 - Confirm location and tax status:

Confirm your location, whether your business is registered in the US or Canada, and if you have a Tax ID (EIN/Employer Identification Number).


  1. If you do not have an EIN, you are eligible to be registered as a Sole Proprietor.
  2. If you do have an EIN and select Yes, you will be redirected to a Customer Support page. Click on Contact Support, where you will receive a Google Form, fill it out and submit it, and our support team will handle the rest.


Step 3 - Go through the details:

Since you selected “No” in Step 2, and without an EIN number, you qualify to register as a Sole Proprietor. So first, know about the messaging capabilities, such as the number of messages you can send, alongside one-time and monthly recurring charges.

Additionally, look at the information that is required for registration. Then, click on the checkbox and confirm that you have read and understood the above information and agreed to register as a Sole Proprietor.


Step 4 - Enter your business details:

Fill in the blanks with the asked details.

  • Legal business name or enter your name
  • Your first and last name
  • A valid business email
  • Business phone number


After filling in all the details, click on Save and Continue.


Then, proceed to the next page and enter your business address.

  • Country Code
  • Street Address
  • Stress Address Line 2
  • City
  • State/Province/Region
  • Postal/ZIP CodeClick Save and Continue.


Step 5 - Review the details of your business:

Confirm that your contact information is correct, including your business name, email address, phone number, and business address. Then, check the box to confirm the declaration and click Submit for Review to proceed.


Step 6 - You have successfully created your business profile on Calilio:

Your business profile has been created successfully, and your details are now on record for A2P messaging. Now, let’s move on to setting up your Brand Details.


Step 7 - Fill in your brand details as a Sole Proprietor:

Click on the Brand section and then enter the following details:

  • Brand name: Enter your business name.
  • Vertical: Select your business falls under which industry from the list of available options, such as Agriculture, Media and Communication, and Entertainment, among others.
  • Mobile phone number: Ensure you dial a traditional or non-VoIP/Virtual mobile number.


Click on the checkbox agreeing that the provided information is correct and consent to receiving a verification message.

Click Register.


Step 8 - Complete the Brand Registration payment:

Select your payment method from the available options, including Visa and Mastercard.  


Step 9 - Verify your mobile number:

You will receive a verification message on the non-VoIP U.S. or Canadian mobile number you entered earlier. Reply “Yes” to continue to the next step.


Step 10 - Further review your A2P Brand:

View your Registration status, Customer type, and External Brand ID, and click Continue.  


Step 11 - Create your A2P campaign:

Fill in the following details:

  • A2P Brand: The brand profile that you created will be available here, so select it.
  • Available A2P Campaign use cases: Sole Proprietors only have the option for the mix use case, and it costs $2 per month.
  • Define your Campaign description (Explain in brief): State whether you will send promotional messages about products or appointments, among other things
  • Place a couple of sample messages in the said boxes: Enter the kind of messages you will be sending to your customers. 
  • Select what your message contains: Check the boxes whether your message will include embedded links and phone numbers.


  • Opt-in: Select either Default or Custom opt-in. If you choose Default, the opt-in keyword will be Start. If you choose Custom, you can define your own preferred opt-in keywords based on what best fits your use case.
  • Opt-in Keywords: Include words like Subscribe or Start. This way, when a recipient sends one of these replies, it clearly shows they consent to receive your messages.
  • Opt-in Message: This is the message your recipient receives to confirm they have agreed to get messages from you. It lets them know they will now receive campaign updates, brand promotions, or other offers.


  • Opt-out: Select either Default or Custom opt-out. If you choose Default, the opt-out keyword will be Stop. If you choose Custom, you can set your own opt-out keywords based on your preference.
  • Opt-out Keywords: Include words like Stop, Unsubscribe, or Cancel. When a recipient sends one of these replies, it clearly shows they no longer want to receive your messages.
  • Opt-out Message: This is the message your recipient receives to confirm they have opted out. It lets them know they will no longer receive campaign updates, brand promotions, or other offers.


  • Help: Select either Default or Custom help options. If you choose Default, the help keyword will be Help. If you choose Custom, you can define your own help keywords to better guide your recipients.
  • Help Keywords: Include words like Help, Support, or Info. When a recipient sends one of these replies, it shows they want more details or assistance.
  • Help Message: This is the message your recipient receives when they ask for help. It provides basic support information and explains how to unsubscribe, such as replying Stop to stop receiving messages.


After filling in all the details, click Create.


Step 12 - Review your A2P campaign details:

Confirm that the sample messages you provided include all required information. Make sure the opt-in and opt-out keywords are clearly defined, and that the help message is properly set up and easy to understand.


Then click on Submit for Review


Step 13 - Register your number:

At this point, you might already have one or more numbers from Calilio, select the numbers you want to use for your A2P campaign. Make sure this is the number that will send your campaign messages.


Step 14 - Finish:

This is the final step in your registration process. Review your customer profile, A2P brand, and campaign details to make sure everything is correct. Once ready, click Confirm to submit your registration for review, and please note that approval usually takes around 2–3 weeks.


Things to know before registering for A2P 10DLC

  • Location requirement: Sole Proprietor Brands are only for customers in the United States or Canada. 
  • No Tax ID allowed: This option is only for customers without a Tax ID, such as a U.S. EIN or a Canadian Business Number.
  • LLCs are not eligible: All U.S. LLCs have an EIN, even single-member or sole proprietorship LLCs. They must register as Standard or Low-Volume Standard Brands.
  • Tax ID holders: Any customer with a Tax ID must use Standard or Low-Volume Standard Brand registration.
  • Outside the U.S. or Canada: Customers located outside the U.S. or Canada must register as Standard or Low-Volume Standard Brands to send messages to the U.S. using 10DLC numbers.
  • Brand Registration Retries: If your brand registration is rejected, you can correct the details and resubmit up to two additional times without paying extra. This gives you a total of three attempts per brand.
  • Campaign Registration Retries: Campaign submissions can be edited and retried if they fail. No extra fees apply when resubmitting corrected campaign details.
  • Numbers Per Campaign: Each A2P 10DLC campaign can support up to 400 phone numbers, allowing you to manage multiple numbers under one campaign.
  • Daily Message Limits: Message limits, usually between 3,000 and 6,000 segments per day, apply at the brand level, not per individual number.
  • Message Sending Rules: Messages can be sent from any registered number, as long as the total daily limit for the brand is not exceeded.
  • Authentication Plus fee:
  • Applies only to public, for-profit businesses when a resubmission is required due to incorrect information.
  • Does not apply to private companies or sole proprietors, which follow a separate fee structure.


Things required for Low Volume A2P Registration

  • Business Name: Legal registered business name
  • Business Type: Legal structure, such as LLC or Corporation
  • Business Industry: Industry your business operates in
  • Business Registration Number: Country-specific tax or registration ID
  • Website URL: Official business website
  • Social Media Links: Business profiles like LinkedIn or Facebook
  • Regions of Operation: Countries or regions you operate in
  • Business Address: Full mailing address with country code
  • Representative Details: Authorized person’s name, role, phone, and email
  • Company Type: Public or private business
  • Brand Contact Email: Email used for verification and alerts


Reasons To Register for A2P 10DLC

Registering for __A2P 10DLC __helps your messages reach customers reliably by avoiding carrier spam filters while increasing trust through verified business numbers. It also ensures carrier compliance, supports higher sending limits at lower cost than short codes, and gives you a dedicated number for SMS, MMS, and voice.


  • Better message delivery: Registered numbers avoid carrier spam filters, so messages like reminders, alerts, and promotions reach customers more consistently. Unregistered messages often fail or get blocked.
  • Stronger customer trust: Verified business numbers show recipients that messages come from a real, approved sender. This improves credibility and increases the chance of replies.
  • Higher sending limits: Carriers allow more messages per second and faster delivery for approved A2P 10DLC campaigns. This is critical for time-sensitive updates.
  • Carrier compliance: Major U.S. carriers require A2P 10DLC to reduce spam and fraud. Without registration, messages may be filtered or rejected.
  • Lower overall cost: A2P 10DLC provides many of the same benefits as short codes but at a lower price, making it a practical option for most businesses.
  • Dedicated business numbers: You use your own long code number, not a shared one. It can support SMS, MMS, and voice, allowing customers to call back if needed.

Updated on: 15/01/2026

Was this article helpful?

Share your feedback

Cancel

Thank you!