A2P 10DLC is the US carrier registration required before a business can text from an ordinary 10-digit number. A dental practice sending appointment reminders, confirmations or recall texts from software is an A2P sender, so the practice's legal entity has to be registered as a brand and its messaging approved as a campaign before AT&T, T-Mobile and Verizon will deliver. Unregistered reminder texts fail quietly — the software shows them as sent and the patient never receives them.
By Viktoria Mols, CMO at Dentovox · Updated September 25, 2026 · Written while taking Dentovox itself through the same registration
General information about carrier requirements as they applied on September 25, 2026 — not legal advice. Carrier and FCC rules change; confirm the current position with your messaging provider and your own counsel.
Registration has two halves, and practices usually confuse them.
The brand is who is sending. It is your practice as a legal entity: legal name, tax ID, business address, website, contact person. Carriers check this against tax records, largely automatically, and it is usually the fast half.
The campaign is what you are sending and how patients consent. It is the use case, the sample messages, how a patient opts in, how they opt out, and what happens when they text HELP. Anything touching healthcare or appointment reminders is commonly pushed into manual vetting, and that is where the time goes.
Both belong to the practice, not only to the vendor. A messaging vendor that is registered itself does not make your traffic registered — your entity and your campaign are what carriers check.
Ask any vendor selling you patient texting two questions: whose brand is the traffic registered under, and is the campaign approved for your practice specifically. If the answer is vague, assume the texts will be filtered. Ask, too, what the product does while registration is pending — because that is the honest measure of whether you will have coverage in the meantime.
We hold ourselves to the same answer. Two-way SMS is built into every Dentovox plan and included at no extra charge, and it is not sending yet: it switches on when our carrier registration completes. Until then Dentovox answers, books and calls lapsed patients back by voice. The status of every capability is on one page, and what the plans cost is on pricing.
A2P 10DLC is the US carrier registration system for application-to-person text messages sent from ordinary 10-digit local numbers. A practice that sends appointment reminders, confirmations or recall texts from software rather than from someone's phone is an A2P sender, so AT&T, T-Mobile and Verizon require the business behind those messages to be registered before they deliver them. It is a carrier requirement, not a government one, and it applies whether the practice sends the texts itself or a vendor sends them on its behalf.
Almost always because the traffic is unregistered or the registration lapsed. Carriers began filtering and then blocking unregistered A2P traffic from 10-digit numbers, and the messages fail silently: the practice sees them as sent, the patient never gets them, and the first symptom is a rise in no-shows. Check whether your messaging vendor has a registered brand and an approved campaign for your practice's own legal entity, not just for the vendor.
Brand registration is usually the quick part, often the same day, because it is largely an automated match against tax records. The campaign is the slow part: use cases that involve healthcare, appointment reminders or anything that could look like marketing are commonly routed to manual vetting, which adds days to weeks. Plan for weeks, not hours, and do not schedule a launch that depends on texting going live on a fixed date.
In order of frequency: the legal name and EIN do not match the IRS record exactly; the business address does not match the one on file; the website in the profile does not exist, does not mention the business by the same name, or has no visible privacy policy; the campaign description does not match what the sample messages actually say; and the opt-in method described cannot be found anywhere on the site. The fix for almost all of these is documentary, not technical.
Yes, and the opt-in has to be documented and available to the carrier. A patient checking a box on an intake form, entering a phone number on a web form that states what it will be used for, or replying to a confirmation request are all acceptable; a phone number that was simply in the chart is not an opt-in for marketing. Every message program also has to honor STOP immediately and answer HELP, and the practice should keep a record of when and how each patient opted in.
Practically, no — not from a 10-digit number at any useful volume. The alternatives each have their own registration: toll-free numbers require toll-free verification, and short codes require a separate application and cost far more. Calling the patient instead is not subject to A2P registration at all, which is why voice-first workflows keep running while a texting program waits in a carrier queue — with the caveat that outbound calls using an artificial, prerecorded or AI voice carry their own prior-express-consent requirement under the TCPA, so the consent record and quiet hours still apply.
This page describes carrier registration requirements as they applied on September 25, 2026, and is general information, not legal advice. Carrier rules change; confirm the current requirements with your messaging provider. Spotted an error? Email info@dentovox.com and we will correct it.