Compliance Guide
A2P 10DLC: What Carrier Registration Covers, and What It Doesn't
What is A2P 10DLC?
Short answerA2P 10DLC (application-to-person, 10-digit long code) is the US wireless carriers' registration system for business text messages sent from ordinary 10-digit phone numbers. A business registers its brand and each campaign through its messaging provider with The Campaign Registry, and the carriers set how many messages it may send from that registration. Carriers have blocked unregistered 10DLC traffic since early February 2025. It is an industry requirement, not a law: registration says nothing about whether you had TCPA consent to text a number, and TCPA consent does not get an unregistered campaign delivered.
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Most businesses meet 10DLC as an error message: texts that stopped delivering, or a campaign rejected with a code nobody explains. It is worth understanding on its own terms, because it is not what most people assume it is. It is not a law, it is not a consent system, and being registered does not make a message legal to send. It is the carriers' way of knowing who is texting their subscribers, and how much.
What A2P 10DLC is
A2P is application-to-person: messages a business sends from software, as opposed to one person texting another. 10DLC is the 10-digit long code, the ordinary local phone number. A2P 10DLC is the standard the US carriers set for business texting from those numbers, and T-Mobile has treated it as a sanctioned route since the fall of 2020. The alternatives are toll-free numbers and short codes, covered below.
The registry at the center of it is The Campaign Registry (TCR). Two things get registered there:
- A brand: the company the recipient believes is sending the message. The brand's identity is checked when it registers, and a brand that fails verification cannot register campaigns.
- A campaign: the use case, meaning the kind of messages the brand will send, such as marketing, customer care or account notifications, together with sample messages and a description of how people opt in.
You do not register with TCR yourself. Your messaging provider submits the brand and campaigns on your behalf, and your provider and the carriers review them. TCR says it does not review, approve or reject campaigns. Carriers have blocked unregistered 10DLC traffic since early February 2025.
Vetting and throughput
Registration decides how much you may send. Throughput follows the brand and the campaign, not the number of phone numbers you rent, so adding numbers does not raise it.
- Most brands start at entry level. Only large public companies (those on the Russell 3000 list) get top limits automatically once verified.
- Vetting raises it. An optional third-party vet reviews the brand and scores it from 0 to 100, and a high score unlocks higher limits. A deeper vet is available if the first result seems wrong.
- The carriers count differently. AT&T sets a limit per campaign, in messages per minute. T-Mobile sets a daily cap per brand, tied to its tax ID and shared across all of that brand's campaigns. Carriers can change these terms at any time.
Some platforms show a "trust score". That is the platform's name for the result of this process, not a separate carrier system.
What it costs
There is a one-time fee to register a brand, an optional fee for each vet, and a monthly fee for each campaign with a three-month minimum, all charged by TCR to providers, which pass them on with their own markup. On top of that, carriers charge a surcharge on every message, and those changed three times in the first half of 2026 alone. Ask your provider for the all-in cost per campaign and per message rather than relying on a figure from a blog.
What the carriers expect of your opt-in
Campaign review is largely a review of your consent process, measured against CTIA's Messaging Principles and Best Practices (May 2023) and each carrier's code of conduct. CTIA sets three levels of consent by message type:
| Message type | Example | Consent CTIA expects |
|---|---|---|
| Conversational | A reply to a question the customer texted first | Implied |
| Informational | Appointment reminders, delivery updates | Express |
| Promotional | Offers, sales, marketing | Express written |
Beyond that, the guidelines expect:
- A clear call to action at the point of opt-in: what the program is, who is sending, which number will send, any charges, how to opt out, how to reach customer care, and a link to the privacy policy.
- Records of each opt-in: when, how, the exact language shown, the campaign, and the phone number.
- A confirmation message for recurring programs, naming the program, how often messages come, how to get help, and how to opt out.
- Opt-outs by more than one route, answered with one final confirmation and then silence. STOP, END, UNSUBSCRIBE, CANCEL and QUIT should all work.
- No transferred consent. An opt-in should not be transferable or assignable, and senders should not use opt-in lists that were rented, sold or shared.
- A privacy policy, easy to find from the call to action. Messaging platforms also expect it to say that mobile opt-in data is not shared with or sold to third parties, and carrier codes of conduct bar sharing consent at all.
Why campaigns get rejected
Messaging platforms report the same causes again and again:
- The opt-in is missing, incomplete or not shown, or relies on a pre-checked box.
- The website cannot be verified: empty, private, or not matching the business name.
- The privacy policy is missing, or lacks the clause saying consent is not shared or sold.
- The sample messages do not match the use case registered.
- The campaign description is too vague to tell what will be sent.
- Messages use a public link shortener rather than one dedicated to the sender.
Almost every one of these is about the consent process or the sender's identity, not the technology. A rejection is usually the reviewers telling you they cannot see who is sending, or how the people you plan to text agreed to it.
Registration is not TCPA compliance
Being registered, vetted and approved says nothing about whether a particular text was lawful. That question belongs to the TCPA, which is enforced by the FCC and by private lawsuits, and carries its own rules:
- Consent. Marketing texts to a mobile need prior express written consent under the FCC's rule (the Fifth Circuit reads the statute to require only prior express consent, oral or written).
- Opt-outs must be honored within 10 business days, across channels.
- Do Not Call. The FCC's rules apply the national registry to marketing texts, though courts are split on whether a consumer can sue over texts. SMS compliance under the TCPA sets out the split.
- Damages are per message: $500 each under § 227(b), up to $1,500 if willful or knowing.
The two systems catch different failures. A carrier can suspend a campaign for a weak opt-in page; only a lawsuit asks whether the person you texted actually agreed. A registered campaign sending to a bought list can fail both.
Toll-free numbers and short codes
- Toll-free (8XX) numbers can be text-enabled and go through their own verification rather than 10DLC registration, and messaging platforms block unverified toll-free traffic.
- Short codes are 5- or 6-digit numbers built for high volume. They are leased through the US Short Code Registry for 3, 6 or 12 months, at $1,000 a month for a code you choose or $500 for a random one as of September 2026, and each campaign needs carrier approval.
The consent and TCPA rules are the same on every route. Only the registration process differs.
Before the first send
- Register the brand and campaign through your provider, with an opt-in page, privacy policy and sample messages that match what you will actually send.
- Hold consent records for every number: the form, the wording, the timestamp.
- Make sure every number on the list can receive a text. A text to a landline fails silently: no bounce, no error, just a message that never arrives.
- Remove known TCPA litigators. Their numbers are real, connected mobiles that pass every quality check, and serial filers often enter them into lead forms so they end up on purchased lists.
- Keep opt-outs flowing into one suppression list that every sending system reads.
NumberBroom covers steps 3 and 4 in one pass: the full scrub keeps only connected mobile numbers that are not known litigators, with line_type, carrier and activity_score appended to every row it keeps. It does not register campaigns or record consent. Link your own FTC subscription (SAN) and the same job adds a federal Do Not Call Registry check, included free on lists of up to 1,000 numbers; state lists stay yours. Upload your list; the first 20 rows preview free before you pay.
Frequently asked questions
Is 10DLC registration required by law?
No. It is required by the carriers, who block unregistered traffic, and it runs on industry guidelines that CTIA itself describes as voluntary best practices. No FCC rule requires it. The FCC's own texting rules make carriers block messages that claim to come from invalid, unallocated or unused numbers, and describe that as consistent with what the industry already does. The law that governs whether you may text someone at all is the TCPA, which registration does not touch.
What is The Campaign Registry?
The Campaign Registry (TCR) is the central database where 10DLC brands and campaigns are registered. You do not register with it directly: your messaging provider submits your brand and campaigns on your behalf. TCR says it does not itself review, approve or reject campaigns. Your provider and the carriers do that.
Can I text a purchased lead list from a registered 10DLC number?
The carriers say no, even in cases where the TCPA might allow it. CTIA's guidelines say an opt-in should not be transferable or assignable and that senders should not use opt-in lists that were rented, sold or shared, and T-Mobile's code of conduct bars buying, selling or sharing consent. A campaign found texting a bought list can be suspended regardless of what the consent form said.
Under the TCPA the question is different: whether the consent the consumer gave named your business. That consent is yours to prove, and a purchased list is also where TCPA litigators collect, because serial filers often enter their numbers into lead forms on purpose.
What is a sole proprietor 10DLC brand?
A registration route for individuals and small businesses in the US or Canada that have no EIN. It allows one campaign and one phone number, and caps volume at 1,000 messages a day to T-Mobile customers and 15 a minute to AT&T. Not every provider offers it, because the provider needs a separate agreement with TCR. A business with an EIN registers as a standard brand.
How do I get higher 10DLC throughput?
Through vetting, not more numbers. Throughput is set by who is sending (the brand) and what is being sent (the campaign). Most brands start at entry-level limits; an optional third-party vet scores the brand from 0 to 100, and a high score unlocks higher limits. AT&T sets limits per campaign in messages per minute, while T-Mobile sets a daily cap per brand shared across all its campaigns. Carriers can change these terms at any time.
- The Campaign Registry -- Resources and FAQ
- The Campaign Registry -- CSP User Guide (July 2026)
- CTIA -- Messaging Principles and Best Practices (May 2023)
- T-Mobile -- Consumer versus non-consumer text messaging
- US Short Code Registry -- FAQs
- FCC 23-21 -- Report and Order on blocking unwanted text messages
- 47 C.F.R. § 64.1200 -- Delivery restrictions (eCFR)