A2P 10DLC is the U.S. carrier framework for sending application-to-person text messages over standard 10-digit long-code phone numbers. It requires businesses to register their brand and campaigns so carriers can vet and properly route the traffic.
A2P 10DLC stands for "application-to-person 10-digit long code." It is the system U.S. mobile carriers use to allow businesses to send automated or bulk text messages from ordinary 10-digit phone numbers—the same format as a normal mobile number—rather than from short codes or toll-free numbers. "Application-to-person" distinguishes business messaging sent by software from "person-to-person" texting between individuals.
The framework exists because carriers wanted a sanctioned, accountable path for business texting over local numbers. Before 10DLC, businesses often sent application traffic over consumer long codes that were never designed for volume, which led to filtering and unpredictable delivery. 10DLC replaces that gray area with a registration-based model in which carriers can identify the sender, understand the use case, and apply consistent throughput and trust rules.
Registration runs through The Campaign Registry (TCR), a central organization that the major U.S. carriers rely on for vetting. The process has two layers. First, the business registers a "brand," providing legal entity details such as company name, tax ID, and contact information, which produces a trust score. Second, it registers one or more "campaigns" describing the specific messaging use case—for example appointment reminders, customer care, or marketing—along with sample messages and opt-in details. Phone numbers are then associated with an approved campaign.
The brand trust score and the campaign type together influence messaging throughput and how aggressively carriers filter the traffic. Well-documented use cases with clear consent tend to receive better deliverability, while vague registrations or content that mismatches the declared use case can be filtered or blocked. Carriers may also charge registration and per-message fees that vary by use case.
Compliance does not end at registration. A2P messaging in the U.S. is also governed by consent rules, including the TCPA, and by industry guidelines such as the CTIA messaging principles. Messages generally require prior opt-in, must honor opt-out keywords like STOP, and must match the registered use case. Registration handles carrier routing and trust; it does not replace the legal obligation to obtain and document consent.
For outbound SMS programs this framework is unavoidable. MediaBloom builds outbound calling and SMS systems for 300+ businesses, and proper 10DLC registration is part of standing up compliant texting: registering the brand and campaigns, mapping numbers correctly, and aligning message content and opt-in flows with what was declared. Skipping registration typically results in heavy filtering or undelivered messages.
Because vetting, throughput tiers, and fees are set by carriers and TCR and can change, the specifics should be confirmed against current carrier and TCR documentation rather than assumed. The durable point is that any business sending automated texts from a standard 10-digit U.S. number needs to register under A2P 10DLC and keep its registration accurate.
Key takeaways
- 10DLC enables business (application-to-person) texting over standard 10-digit U.S. numbers.
- Registration runs through The Campaign Registry at both the brand and campaign level.
- Brand trust score and campaign type affect throughput and carrier filtering.
- Registration does not replace consent law; TCPA and opt-out rules still apply.
- Unregistered A2P traffic is typically filtered or blocked by carriers.
Related terms
TCPA
The TCPA is a U.S. federal law that restricts certain telemarketing calls, texts, and the use of automated dialing and prerecorded messages, generally requiring prior consent before businesses can contact consumers.
DNC Registry
The DNC Registry is a U.S. list of phone numbers that consumers have registered to opt out of most telemarketing calls, which telemarketers are generally required to check and respect.
Power Dialer
A power dialer is outbound calling software that automatically dials numbers from a list one after another and connects answered calls to an available agent, removing manual dialing and increasing talk time.
Cold Calling
Cold calling is the practice of phoning prospects who have not previously expressed interest, in order to introduce an offer and start a sales conversation.
Email Deliverability
Email deliverability is the ability of an email to reach the recipient's inbox rather than the spam folder or being blocked entirely. It depends on authentication, sender reputation, content, and recipient engagement.