What A2P 10DLC is
- A2P (application-to-person): texts sent by software or a platform, rather than typed one at a time by a person on their own phone.
- 10DLC (10-digit long code): an ordinary US phone number, as opposed to a 5- or 6-digit short code or a toll-free number.
Registration tells the carriers two things: who you are (your brand) and what you send (your campaign). Carriers use it to tell legitimate business texting apart from spam.
Does your business need it?
Usually yes, if you send texts like these from a 10-digit number through any software:
- Appointment confirmations and reminders
- “Your technician is on the way” updates
- Texts sent automatically after a missed call
- Booking links, estimates or invoice notifications
Your texting provider (a messaging platform, phone system, CRM or field-service app) normally handles registration with you. If you send any of the above and have never been asked for your business details, ask your provider whether your numbers are registered.
What happens if you don’t register
Messages may simply not arrive. Twilio, one of the largest messaging platforms, states that since September 1, 2023, all US-bound SMS and MMS sent from unregistered +1 10DLC numbers on its platform are blocked, returning error code 30034. For a service business, that can mean appointment confirmations that never reach the customer — without anyone noticing.
Source: Twilio: full blocking of unregistered US A2P 10DLC traffic.
How registration works
- Register your brand. You provide your business details: legal business name, tax ID (EIN), business address, website and a contact person.
- Register a campaign. You describe what you’ll send (for example, appointment notifications), how customers opt in, and provide sample messages.
- Link your numbers. Each 10-digit number you text from is associated with an approved campaign.
- Wait for review. Some brands and campaigns are approved quickly; others need manual review. Timing and fees depend on your provider.
Sole proprietors
Businesses without an EIN can register as a Sole Proprietor brand. According to Twilio’s documentation, Sole Proprietor brands are limited to one campaign, one phone number and one message per second — usually plenty for a one-person service business. A sole proprietorship that does have an EIN must register as a standard or low-volume brand instead.
Source: Twilio: Direct Sole Proprietor registration overview.
Consent, STOP and HELP
Registration is only half of it. CTIA’s Messaging Principles and Best Practices, which carriers rely on, set out how consent should work:
- Opt-in first. Send messages only after the customer has agreed to receive them, and make clear who is texting, what they’ll receive and any terms.
- Honor opt-outs. Respect STOP and plain-language requests such as “unsubscribe” or “please stop,” and send one final confirmation.
- Answer HELP with how to reach your business.
- Keep records of opt-ins and opt-outs.
For a service business, the natural opt-in moment is booking: “Can we text you appointment updates at this number?” Laws can add further requirements beyond these guidelines. If you’re unsure what applies to your business, it’s worth a quick question to a lawyer — for example through HelpByExperts’ ask-a-lawyer service, a sister service from iClick Solutions, the company behind Voxenara.
Source: CTIA Messaging Principles and Best Practices (May 2023).
Sample messages for a service business
Campaign reviewers want samples that match what you’ll actually send, name your business and include opt-out language. Adapt these:
Appointment confirmation
[Company]: You’re booked for [service] on [day] between [window]. Reply C to confirm or call [number] to reschedule. Reply STOP to opt out.
Reminder
[Company]: Reminder — your technician arrives tomorrow between [window]. Reply STOP to opt out.
On the way
[Company]: [Technician first name] is on the way and should arrive in about [time]. Reply STOP to opt out.
After a missed call
[Company]: Sorry we missed your call. Reply with what you need and we’ll get back to you, or book at [link]. Reply STOP to opt out.
More templates for busy periods are in our storm call surge playbook.
Avoiding rejections and delays
- Match your records exactly. Use your legal business name and EIN as they appear on your tax records, not a nickname or DBA, unless your provider asks for it.
- Have a working website that matches your business name and explains how customers opt in to texts.
- Keep samples consistent with the use case you choose; don’t register for appointment reminders and then send promotions.
- Register early, before a busy season when you’ll rely on texting.
Texting is often paired with phone answering: a missed-call text-back or a booking confirmation after a call. See how Voxenara handles calls and confirmations for home-service businesses.
Frequently asked questions
What is A2P 10DLC?
A2P means application-to-person: texts sent by software rather than typed by a person on a phone. 10DLC means a standard 10-digit long code, an ordinary US phone number. A2P 10DLC registration tells US carriers who your business is and what kind of texts you send from those numbers.
What happens if I don't register?
Your texts may not be delivered. Twilio, for example, says that since September 1, 2023 all US-bound SMS and MMS from unregistered 10DLC numbers on its platform are blocked, returning error 30034. Other providers apply the same carrier requirement.
Can a sole proprietor register for A2P 10DLC?
Yes. Businesses without an EIN can register as a Sole Proprietor brand, which Twilio's documentation says is limited to one campaign, one phone number and one message per second. A sole proprietorship that has an EIN must register as a standard or low-volume brand instead.
Do customers have to opt in before I text them?
Industry guidelines from CTIA say messages should only be sent after the person has opted in, that opt-out requests such as STOP must be honored, and that senders should keep records of opt-ins and opt-outs. Laws can impose additional requirements, so check your specific situation.
How long does A2P 10DLC registration take?
It varies by provider, by brand type and by whether your campaign needs manual review. Register well before you need to rely on texting, and make sure your business details match your official records exactly to avoid delays.