10DLC Registration for AI Receptionists That Text Callers

What 10DLC is, and why a voice agent runs into it

10DLC stands for ten-digit long code: an ordinary US phone number that a business uses to text people. The Campaign Registry, which runs the register, calls it the standard the US mobile networks have sanctioned for business texting from such numbers, and every business that texts customers this way has to register, including for one-off texts that are not marketing. The carriers in that chain are T-Mobile, AT&T, Verizon and US Cellular. Telnyx has blocked unregistered 10DLC traffic since early February 2025, so there is no grace period left to lean on.

For a voice agent the requirement lands in an unexpected place. The phone call needs no registration, and the receptionist can answer US callers from the first day. Only the text with the booking link needs it, and that text is usually the reason the caller is happy with the call. Why a link to the booking page beats a connection to the booking system is explained in our guide to building an AI receptionist platform, and what a real connection asks of you is in tool calls to business systems. This article is about getting that link delivered in the US.

Build the receptionist now, and start the registration the day a US client signs.

The four steps

Telnyx is the campaign service provider in this chain: you do all four steps in its portal or through its API, and it passes the campaign on to the carriers. The Campaign Registry records brands and campaigns but does not approve them; the providers in the chain do.

1. 01

   Register the brand

   The brand is the business. The registry checks its EIN, legal name and address against independent sources.
2. 02

   Vet the brand (optional)

   A third-party check of the business. It raises the throughput limits, and Telnyx lists an unvetted brand among the reasons campaigns are rejected.
3. 03

   Register the campaign

   What the business will text, why, and how people agree to receive it. Telnyx reviews it first, then the carriers.
4. 04

   Assign the number

   Once the campaign is approved, assign the number to it. The number has to sit on a messaging profile before you can.

One step comes before all of this: Telnyx only accepts 10DLC registrations from an account that has completed its own verification. On accounts in its older framework that is Level 2. Do it first, because it is the one step that does not depend on your client.

What the business needs before you start

Everything starts with the legal entity. The registry needs the EIN and the legal name exactly as the IRS has it, and the most common reason a brand stays unverified is a name that does not match the federal records. “Bright Smile Dental” on the sign and “Bright Smile Dental Care PLLC” at the IRS are two different names to a reviewer. Next to that it needs a physical address (a PO box is generally refused), a website that is live, a support email and phone number, and the industry.

The website does real work in the review. It has to carry the business's own privacy policy, not yours as the agency, with a sentence saying that mobile information will not be sold or shared with third parties for promotional or marketing purposes. A policy that only promises not to sell it is not enough. The terms on the same site mention that message and data rates may apply and how to reach customer care. Both links go into the registration, so check them before you submit anything.

Writing the campaign for a receptionist

Most rejections come from the campaign, because the reviewers compare everything: the use case, the description, the sample messages, the opt-in description and the website have to tell the same story. Write it from what the receptionist actually does, not from what it might do one day.

The use case that describes this traffic is Customer Care: a business answering a person who contacted it. Low Volume Mixed costs $1.50 a month instead of $10 and is meant for brands that send very little; Telnyx puts the ceiling at 6,000 messages a month, far above what a receptionist sends. Either can fit. Pick the one whose description matches what you will send, because the samples are checked against it.

Bright Smile Dental sends a single text message to a caller who asks for it
during a phone call with the practice's AI receptionist. The message contains
a link to the practice's online booking page, so the caller can choose an
appointment time. One message per request. No marketing.

1. Bright Smile Dental: here is the link to book your appointment:
   https://brightsmiledental.com/book Reply STOP to opt out.

2. Bright Smile Dental: you can move your appointment here:
   https://brightsmiledental.com/patients Reply STOP to opt out.

Telnyx's form asks for two samples. Start each with the name of the business, because the text often comes from a different number than the one the caller dialled, and end with the opt-out line: a sample without it is one of the reasons Telnyx lists for rejection. Because the samples contain a link, tick “embedded link” in the registration.

Consent that happens on a phone call

The field that trips up voice agents is the call-to-action, or message flow: how does the person agree to receive the text? Every opt-in method has to be listed and has to be verifiable. For most businesses the answer is a web form. For a receptionist the answer is the call itself: the caller asks for the text, or agrees to it, out loud.

That is allowed. CTIA's messaging principles accept verbal consent for informational messages and list opt-in by phone through an IVR as a valid method. Telnyx accepts a verbal opt-in when the flow is described: the agent offers the text with a fixed sentence, the caller agrees, the number is recorded and the text follows. Marketing needs a double opt-in, where the person replies YES to a first text. A booking link sent on request is not marketing, so keep it that way.

Callers to Bright Smile Dental speak with an AI receptionist. When a caller
wants an appointment, the receptionist asks: "Would you like me to text you a
link to book online?" Only if the caller says yes, one text message with the
booking link is sent to the phone number the caller is calling from. The
consent, the time and the number are stored with the call record.
Message and data rates may apply. Reply STOP to opt out, HELP for help.
Privacy policy: https://brightsmiledental.com/privacy
Terms: https://brightsmiledental.com/terms

Keep the record. CTIA asks for the time, the medium, the wording and the phone number, and the transcript of the call, with the moment the caller said yes, covers all four. The number is the one the call came from, which arrives as a full international number, as described in knowing who is calling. One warning about the “fixed sentence”: a voice model paraphrases, a full-duplex model such as GPT-Live-1 included, and an instruction in a prompt is not a guarantee that it is said. Test that the offer comes out the way the registration describes it, with the method in the rules in your prompt that never run.

Federal law points the same way. In its 2015 ruling (FCC 15-72, paragraph 106) the FCC held that a one-time text is lawful when the consumer requested it, it is sent immediately in response, and it contains only the requested information, with no marketing. That case was about a consumer who texted first. Applying it to a request made during a voice call is our reading by analogy, not a ruling, and this article is not legal advice. What it does tell you is how to write the text: one message, the link, and nothing promotional.

Opting out is handled for you. Telnyx blocks a recipient who replies STOP, STOPALL, UNSUBSCRIBE, CANCEL, END or QUIT, and that block applies to the whole messaging profile. That detail matters as soon as you have more than one client, as the next sections show.

What the text itself may contain

One registration per client

If you build receptionists for several businesses, each one is its own brand with its own campaign. Telnyx is explicit: one brand per end customer, and numbers cannot be shared across brands. The registry defines the brand as the entity the recipient believes is sending the message, and that is your client, not you. Texting for many clients under one brand needs a number-pooling agreement with T-Mobile, which Telnyx says is unlikely to be approved outside franchises, and it risks fines.

Your role is reseller: you are named as such on each client's campaign. You do not need to become a campaign service provider yourself.

In practice that means a registered number per US client, and in our advice a messaging profile per client as well. The second is not a Telnyx rule. It follows from how opt-outs work: a STOP blocks the recipient for the whole profile, so on a shared profile a caller who unsubscribes from one business stops receiving texts from all of them. The build in our guide starts with one sender for testing; when the first US client signs, ask Claude to store the number and the profile per client. How we work with agencies on the layer underneath is on the agencies page.

What it costs in 2026

For a receptionist the campaign fee is the largest line, not the messages. A practice that sends a hundred booking links a month pays less than a dollar for the texts and $10 for a Customer Care campaign. That is worth knowing when you price the service: the text costs you a fixed amount per client per month, whatever the call volume. How the other meters of a call add up is in what a voice agent really costs per minute, and what we charge per minute is on our pricing page.

How long it takes

Added up, that is one to two weeks when everything is right the first time. The Campaign Registry itself says campaign review can take one to four weeks, and a rejected campaign starts over, with another $15. Plan for two to three weeks from the day you submit, and use them: the receptionist answers US calls from day one, only the text waits. Test the text flow in the meantime with a number outside North America.

Throughput will not be your problem. AT&T allows a Low Volume Mixed campaign 75 messages a minute, and T-Mobile caps a brand at 2,000 a day in its lowest tier, while a receptionist sends a handful. One catch: the T-Mobile cap belongs to the EIN and is shared by every campaign of that business, so if the client's CRM also sends texts, they share it. And keep the number assigned once you are approved: Telnyx marks a campaign dormant after fifteen days without messages and without numbers.

Toll-free verification instead

The alternative is to text from a toll-free number and have that number verified. It no longer avoids the paperwork: since 17 February 2026 a new verification needs a business registration number, which is the EIN for a US business and the Business Number for a Canadian one. Telnyx's toll-free documentation puts verification at one to two weeks. Until then the number is blocked or heavily filtered (Telnyx's own pages differ on which), so do not send before it is verified. Verbal opt-in is accepted here too, with the same double opt-in for marketing.

Our view: for a business whose callers expect a local number, 10DLC. For a receptionist that serves callers in both the US and Canada, a verified toll-free number is the simpler route.

Canada and Puerto Rico

In all three places a text cannot come from a sender name; Telnyx does not support alphanumeric sender IDs to the US, Canada or Puerto Rico. Beyond that they differ.

Canada has no 10DLC registry of its own, and we found no Canadian carrier or regulator that requires one. Canadian carriers do filter business texts strictly, which makes a verified toll-free number, valid in both countries, the dependable route. Canada's anti-spam law exempts a message sent in response to a request, inquiry or complaint from its consent rules, which fits a booking link the caller asked for.

Puerto Rico uses US numbers (+1 787 and 939), and according to Twilio's country guidelines its operators follow the US rules, including 10DLC. We found no Puerto Rican primary source on this, so treat it as the US and register.

Why campaigns get rejected

These are the reasons Telnyx lists, and how to stay clear of each: