December 3, 2025 MOBITELSMS Engineering 8 min read

If you send Application-to-Person (A2P) SMS traffic to US mobile numbers using standard 10-digit long codes, you need to register through the 10DLC framework. This is not optional. Carriers now require it, and unregistered traffic faces severe throughput throttling, filtering, or outright blocking. Here is a practical guide to what 10DLC is, how the registration process works, and what to watch out for.

What Is 10DLC?

10DLC stands for 10-Digit Long Code. Historically, long codes (standard phone numbers like +1 512 555 0199) were designed for person-to-person (P2P) messaging. Businesses that needed high-volume A2P delivery typically used short codes (5- or 6-digit numbers) or toll-free numbers. But as more businesses adopted long codes for A2P messaging -- appointment reminders, OTP codes, marketing campaigns -- carriers needed a way to distinguish legitimate business traffic from spam.

The 10DLC system, managed by The Campaign Registry (TCR), creates a formal registration layer between businesses sending A2P messages and the carriers delivering them. Every business (brand) registers once, then registers each messaging use case (campaign) separately. Carriers use this registration data to assign throughput limits, apply filtering rules, and enforce compliance.

Why Registration Is Mandatory

T-Mobile was the first major US carrier to enforce 10DLC registration requirements, with AT&T following shortly after. As of late 2023, all three major US carriers (T-Mobile, AT&T, and Verizon) require 10DLC registration for A2P long code traffic. The consequences of not registering are real:

The Brand Registration Process

Brand registration is the first step. You register your business entity once with TCR, providing the following information:

Once submitted, TCR runs a brand vetting process. This cross-references your business information against public records, tax databases, and third-party data sources. The vetting process produces a Trust Score ranging from 0 to 100. This score directly determines your throughput limits.

Brand Vetting Scores and Throughput Tiers

Your Trust Score places you into one of several throughput tiers. The exact thresholds vary by carrier, but the general structure looks like this:

If your initial score is too low, you can request a manual external vet through third-party vetting providers (like WMC Global or Aegis Mobile) for an additional fee, typically around $40. External vetting often raises your score significantly, especially for legitimate businesses whose information is well-documented in public records.

Campaign Registration

After your brand is registered and vetted, you register individual campaigns. Each campaign represents a specific messaging use case. TCR defines several standard use case categories:

Each campaign registration requires you to provide sample messages -- typically 2-5 examples of the actual messages your campaign will send. Carriers review these samples to confirm they match the declared use case.

What Carriers Look for in Message Samples

Carriers and TCR reviewers pay close attention to your sample messages. They are checking for:

Common Rejection Reasons

Campaign registrations are rejected more often than most senders expect. The most common reasons include:

  1. Mismatched use case -- Registering as "Customer Care" when you are actually sending marketing messages. Be honest about your use case.
  2. Missing opt-in documentation -- You must describe how subscribers consent to receive your messages (web form, keyword opt-in, paper form, etc.).
  3. Vague sample messages -- Samples like "Hi, check this out" do not demonstrate a clear business purpose.
  4. Website issues -- Your declared website must be live, must match the registered brand, and should contain a privacy policy and terms of service.
  5. EIN mismatch -- The company name and EIN must match exactly what is on file with the IRS. Even minor discrepancies (LLC vs Inc., extra spaces) cause failures.

Timeline: What to Expect

The typical registration timeline breaks down as follows:

How MOBITELSMS Handles 10DLC

MOBITELSMS includes built-in TCR integration at the platform level. Rather than managing 10DLC registration through a third-party dashboard, you handle everything directly from the MOBITELSMS admin panel:

The goal is to keep 10DLC compliance out of your way while ensuring your traffic is never at risk. Registration is a one-time process per brand and per campaign. Once configured, the platform handles the ongoing enforcement automatically.

If you are sending A2P traffic to US numbers today without 10DLC registration, the time to register is now. The longer you wait, the more likely your traffic is being silently filtered or throttled. Start your registration from the MOBITELSMS dashboard or contact our compliance team for guidance on complex multi-brand setups.