A2P 10DLC

A2P 10DLC is the registration that wireless carriers expect before a business sends application-to-person text messages from an ordinary ten-digit phone number. It decides whether a message is carried. It decides nothing about whether the message was lawful to send. Two different tests, applied by two different kinds of body, and clearing one of them tells you nothing about the other.

Nobody in government wrote this rule

There is no statute behind 10DLC and no federal rule creating it. The closest thing to a public standard is a document published by CTIA, the wireless industry trade association, which calls itself "a set of voluntary best practices developed by CTIA's member companies". Its own scope section says it does "not constitute or convey legal advice" and does "not impose, prescribe, or require contractual or technical implementation" on anyone. Carriers may add to it privately.

Who actually defines the term

Not that document. The phrase 10DLC never appears in it, and neither does the term long code. It speaks instead of "10-digit telephone numbers assigned from the NANP", and of "Registrars" that "operate databases of telephone numbers". The working definition comes from one of those private companies: The Campaign Registry calls 10DLC "an A2P messaging channel in which Brands and Campaign Service Providers (CSPs) are verified prior to being allowed to send messages". A corporation wrote that sentence, not a rulemaking.

Consent is law, carriage is commerce

The legal question lives in 47 U.S.C. 227 and the FCC rules at 47 CFR 64.1200, which is where prior express written consent and revocation of consent are settled. The industry document keeps the two apart itself, listing the TCPA, the CAN-SPAM Act, the Communications Act of 1934 and the FTC Act as separate legal requirements and telling readers to take legal advice. Registration does not cure a missing consent, and a valid consent does not oblige a carrier to deliver anything.

Why the message disappears without an error

The CTIA document says carriers "may filter or block Unwanted Messages before they reach Consumers", and that they "may notify the Message Sender" when they do. May, in both halves of that sentence. Notification is discretionary, so a sending report can show a message accepted while the handset never receives it. The same document counts as unwanted any message "that required an opt-in but did not obtain such opt-in (or such opt-in was revoked)".

The two sentences that bite a purchased list

Two lines in that document speak straight to contact records obtained from someone else. One: "A Consumer opt-in to receive messages should not be transferable or assignable." Two: "Message Senders should not use opt-in lists that have been rented, sold, or shared to send messages." Neither line is a statute and neither can be enforced in court. Both are written by the parties who decide whether your traffic moves, which is a different kind of weight.

Figures this page refuses to print

Throughput tiers, registration and campaign fees, and the score a registered brand is assigned are set privately and revised without announcement. They circulate widely in vendor articles that cite other vendor articles. No document that can be opened and read states them, so none of them appear above. Treat any specific number you are quoted as a claim, and ask which document it came from.

Source: CTIA, "Messaging Principles and Best Practices", May 2023, the 22-page PDF at api.ctia.org, extracted and read in full on 20 September 2026. It supports the description of the document as voluntary best practices developed by CTIA member companies, the scope section stating that it conveys no legal advice and imposes nothing, the separate list of legal requirements including the TCPA and the FTC Act, the coverage of 10-digit NANP telephone numbers, the definition of Registrars as operators of telephone number databases, the definition of an unwanted message as including one that required an opt-in but did not obtain it, the statement that providers may filter or block and may notify the sender, and the two expectations that an opt-in is not transferable or assignable and that rented, sold, or shared opt-in lists should not be used. It does not contain the term 10DLC, the term long code, or the name of any registry company, and it does not define brand registration, vetting scores, fees, or throughput tiers. Source: The Campaign Registry, campaignregistry.com, home page read on 20 September 2026, footer naming Campaign Registry, INC. It supports one thing only, the sentence quoted above defining 10DLC as an A2P messaging channel in which brands and campaign service providers are verified before being allowed to send, and the fact that a private corporation rather than a regulator publishes that definition. Nothing else on this page rests on it, and no carrier's own policy document was opened, so no individual carrier position is described here.