FAQ US carrier registration

To decrease the amount of spam texts and calls received by customers of all major US cell phone carriers, AT&T, Verizon, and T-Mobile require businesses to comply with a new standard. Referred to as A2P 10DLC, this standard ensures that SMS and MMS messages and voice calls to US numbers are sent by verified virtual phone numbers.

All OpenPhone subscribers must register. These FAQs will help you understand the standard and successfully register. Also, fully review our US carrier registration guide for more information on how to get registered.

What is A2P 10DLC?

A2P 10DLC refers to a standard in the United States that allows businesses to send Application-to-Person (A2P) type messaging via standard 10-digit long code(10DLC) phone numbers. Major US carriers consider all messages sent using virtual phone numbers with local area codes, like the ones provided by OpenPhone, to be A2P.

Who is required to register as a US carrier?

Every OpenPhone customer, as virtual phone users who send texts to any US number needs to register, whether using OpenPhone for business or personal use (i.e., texting friends and family). We are not able to support a personal use case exemption at this time.


  • Brand - The identifier for your organization or who you are
  • Campaign - The type of text messages you’re sending across carrier networks

How to access and complete the US carrier registration form

  1. Go to your OpenPhone account’s settings page.
  2. Select “Trust”.
  3. Click “Get started” to go through a short questionnaire to confirm your eligibility.

Can I register now as a sole proprietor if I don’t have a business EIN?

Yes. If you’re the sole proprietor (owner) of a business without an EIN (or equivalent business tax ID) and based in the US or Canada, you can follow the instructions outlined here to get registered.

Can I register now for personal use? 

Yes. If you use OpenPhone to only text your friends and family you can register through our personal use path. You'll need to have:

  • a US or Canadian address
  • a working mobile number with a country code of +1

Check out our guide for more information on registering through the personal use path.

How long does registration take?

The time for completing the entire registration process can vary. We have received some approvals as quickly as 5-7 business days; others have remained in pending status for up to 30 days. In rare cases where key information is unable to be verified expediently, registration may take longer than 30 days. Reminder - You are not able to message US numbers while awaiting registration approval. 

Are there additional charges to send text messages?

Yes. However, these fees are not charged by OpenPhone. US carriers are working with The Campaign Registry and other third parties to review submissions from users across all virtual phone service providers. These third parties charge a one-time $19 fee, which OpenPhone collects on behalf of The Campaign Registry and forwards to them upon registration. In addition to the one-time fee, The Campaign Registry also charges an ongoing monthly fee for keeping your registration in good standing with US carriers:

If your submission is not approved, you'll need to pay a $15 resubmission fee.

Who is The Campaign Registry?

The Campaign Registry is a third-party organization that works with North American mobile operators and companies to help their customers register based on emerging new regulations pushed for by the large US cell carriers (AT&T, Verizon, etc.).

What happens once I complete and submit the registration form? 

You can easily track the progress of your application by returning to the “Trust” settings.

Is OpenPhone responsible for these new regulations?

No. In an effort to combat spam, US carriers require local 10-digit phone numbers powered by applications like OpenPhone must be registered before sending messages to US numbers. These changes and are not determined by OpenPhone.

Can I change to a virtual phone service that doesn't require registration?

As a US carrier requirement, you will be required to register even if you subscribe to another virtual phone service. Other virtual business phone services either require or highly recommend immediate registration upon sign-up. Because the registration fees OpenPhone collects are pass-through fees, you could expect to pay the same fees with a new provider. 

The majority of virtual phone providers required A2P 10DLC registration as far back as March 31st, 2023. However, we're aware of a small handful of virtual phone providers who have yet to disclose a cutoff date. Based on conversations within our industry, customers of providers not requiring registration are experiencing high levels of message filtering. We expect an industry-wide cutoff date for unregistered messages in the coming months.

Do I need to register a toll-free number using the carrier registration form?

If you have a single toll-free number on OpenPhone, you don't need to complete the carrier registration form mentioned above. If you use your toll-free number to send text messages, you can get toll-free verified

Do I register or port my number over first?

Yes, we recommend waiting until your carrier registration application is approved and then submitting your request to port a number to OpenPhone. If you don’t have an active account with us yet, you can sign up for a temporary phone number and then get your workspace registered.

If I add a number to my workspace do I need to register again? 

No. Completing one carrier registration covers all phone numbers in your workspace. 

If I registered with another provider before moving to OpenPhone do I have to register again?

Yes, all new OpenPhone subscribers need to register upon signup. 

If I have a Canadian phone number, do I still need to register? 

Yes. If you are texting from a Canadian number to a US number, you will need to register.

What types of messages are prohibited from being sent?

Our guide to messaging categories and examples not allowed on our platform covers all prohibited use cases. 

Do I have to register with the Free Caller Registry also?

If you’re following best practices and are still being marked as SPAM on your recipient’s caller ID, consider registering with the Free Caller Registry (FCR). This registration process can take weeks to process on the FCR’s end. 


STIR/SHAKEN (also referred to as SHAKEN/STIR ) is a protocol mandated by the FCC.  It's a caller authentication framework developed by ATIS and IETF that helps reduce fraudulent robocalls.

With STIR/SHAKEN protocols, carriers may flag non-compliant callers on the recipient’s caller ID as:

  • Possible spam
  • Suspected robocall
  • Scam likely

How can I check whether my registration was approved?

After you’ve submitted the US carrier registration form, you can easily track the progress of your application by returning to the “Trust” settings from the web or desktop app.

Are there text volume thresholds for which registration isn’t required?

No, if you use OpenPhone to send business texts to any US phone number, you’ll need to complete the US carrier registration form. 

Are there limits to how many texts I can send after registering?

Yes. These limits will be made clear to you during registration. On average, these limits exceed typical text message usage; usually in the order of thousands of messages per day.

Can I expedite my US Carrier registration?

No. Each application is manually reviewed by The Campaign Registry and another third-party entity. They currently have a backlog of registration requests from thousands of businesses worldwideto. Keep in mind your registration may take weeks to process on the carriers’ end.

Is anyone ineligible to register?

Yes. Unfortunately, certain OpenPhone users do not meet US carriers’ requirements for registration.

  • Individuals using OpenPhone for personal use must have a US or Canadian address and local phone number that is not powered by an application like OpenPhone.
  • Businesses without a government tax ID must have a US or Canadian address and local phone number that is not powered by an application like OpenPhone.
  • Businesses with a government tax ID can register from anywhere with any phone number.

If I’m not eligible to register, what can I do?

We recommend getting then switching to a toll-free number, which isn’t currently bound by these new regulations.

If my registration is rejected, what can I do?

A third-party company handles the verification of your information, and we do not have any control over whether your application is approved or rejected. The information we receive is limited. However, you can view the reason your application was rejected in-app and in a related email. You should reference this information to resubmit your application for approval.

Important: Your text messages will only be successfully delivered if you have a successful registration.