If you have tried to switch on automated texting for your business, such as a text to people whose call you missed, or a review request after a job, you have probably met the phrase A2P 10DLC. It sounds technical, and the approval is not in your control, which is why it catches small businesses out. This guide explains what it is, what you need, and what happens after.
What the letters mean
- A2P, application-to-person. Texts sent by software on a business’s behalf, as opposed to a person typing on their own phone (person-to-person).
- 10DLC, 10-digit long code. An ordinary 10-digit US phone number, the kind a local business already has. The alternatives are short codes (5 or 6 digits) and toll-free numbers, which have their own, separate approval processes.
Put together: A2P 10DLC is business texting from a normal local number. US carriers require it to be registered.
Why carriers require it
Carriers want to know who is sending business texts and why, so they can let wanted messages through and filter spam. Registration gives them that record. Unregistered business traffic is blocked.
The block is real. One large texting platform, Twilio, states that “all unregistered messages bound for the U.S. from +1 10DLC numbers are blocked starting September 1st., 2023”, and that its messaging rates “will still apply, even for blocked messages” (Twilio changelog, read 2026-10-22). Other providers apply the same carrier rules. If your texts are not registered, assume they do not arrive.
Who does what
Three parties are involved:
- You, the brand. The business sending the messages.
- Your texting provider. The phone or messaging platform you use. It submits your registration.
- The Campaign Registry (TCR) and the carriers. TCR is the registry used for 10DLC; it says direct registration “is not available for Brands”, so brands register through a provider (campaignregistry.com, read 2026-10-22). The carriers then review and approve or reject.
You register two things:
- The brand: your business’s legal identity.
- The campaign: what you will text about, such as replying to customers who called, appointment reminders, or review requests, with sample messages and how people agree to receive them.
What to have ready
Get these right the first time; a rejection means a resubmission and more waiting.
- Legal business name exactly as registered with the IRS, not your trading name or a shortened version
- EIN (employer identification number), matching that legal name
- Business address that matches your records
- Business type (LLC, corporation, sole proprietor)
- A working website, ideally with a privacy policy that covers texting; many providers ask for a line saying mobile numbers are not shared or sold
- A contact person, with an email and a phone number
- A description of your texts and two or more sample messages
- How people opt in, described plainly: for example, “customers who call us and do not reach us receive one text inviting them to reply”
Sole proprietors without an EIN can often register under a separate, more limited sole-proprietor type. Limits apply; Twilio, for example, allows only one 10DLC number on a sole-proprietor campaign (Twilio error 30034 documentation, read 2026-10-22). Ask your provider which type fits.
How long it takes
The carriers decide, and we will not give you a number of days we do not control. Treat registration as a gating step: start it before you need it, keep your voicemail greeting useful in the meantime, and do not promise customers texts by a date. Registration has fees, usually a one-time brand fee and a recurring campaign fee; ask your provider for its current figures.
Consent: the part that lasts after approval
Registration gets your texts through. Consent decides what you are allowed to send. The CTIA Messaging Principles and Best Practices (May 2023, read 2026-10-22), the guidelines carriers expect senders to follow, sort business texts into three kinds:
| Kind | Example | Consent expected |
|---|---|---|
| Conversational | The customer texts or calls you first, and you reply about that request | Implied: no extra permission when you only respond |
| Informational | Appointment reminders, a job update, a welcome text | Express consent: the customer gave you their number for that purpose |
| Promotional | A seasonal offer, a discount, “book your tune-up now” | Express written consent, such as a ticked box on a form |
CTIA also notes that adding a call to action such as a coupon code to an informational text “may place the message in the promotional category”. So a missed-call text that says “Sorry we missed you, reply here” is a reply; the same text with “and get 10% off” is marketing.
This is not legal advice. Federal law (the Telephone Consumer Protection Act) and some state laws also apply to business texting; check with your own adviser for anything beyond replies and reminders.
Opt-out rules
CTIA’s guidelines (section 5.1.3) say senders should:
- let people opt out at any time, by text, call or email
- use “STOP” in opt-out instructions, and also act on normal words such as stop, end, unsubscribe, cancel and quit
- send one final confirmation after an opt-out, and nothing after that
They also say not to use opt-in lists that have been rented, sold or shared (section 5.1.4). Build your own list from your own customers.
After approval
- Link every sending number to the approved campaign in your provider’s settings. A number that is not linked is treated as unregistered.
- Send what you registered. If you start sending a new kind of message, such as promotions on a campaign registered for replies, update the campaign first.
- Keep sample messages honest. Carriers compare what you send with what you described.
- Keep the opt-out working. Test it with your own phone.
How this affects missed-call text-back and review requests
Both are A2P texts. Until registration is approved, neither can be sent from your local number. That is why every Biz Up plan says texting starts once the carriers approve, and why call answering (which needs no registration) can go live first. The mechanics of the text itself are in missed-call text-back explained, and the rules for review requests in how to get more Google reviews.
At Biz Up the registration is in your business’s own name. You submit it with our step-by-step guide, and we prepare the description and sample messages from your plan, so the campaign matches what the AI Voice Wizard and Review Wizard will send. Registration fees and text usage are billed to your own account. See how going live works and the AI Voice + Review Wizard plan.