Quick Overview #

10DLC (ten-digit long code) is the US carrier-approved channel for application-to-person texting using local numbers. To send A2P on 10DLC, brands register with The Campaign Registry, then register a campaign and assign phone numbers. Carriers enforce policies on consent, brand identification, STOP/HELP support and restricted content.

If you are unsure whether a message meets policy, paste it into the 10DLC Compliance Checker or use the Chrome extension.

Top Questions & Answers #

1) Do all major US carriers require 10DLC registration for A2P long-code messaging?
Yes. AT&T, T-Mobile and Verizon require brands and campaigns to be registered via TCR and they enforce content and consent rules across A2P messaging. See the carrier policy pages and CTIA guidance below.
2) What are the core steps to register for 10DLC?
  1. Register your brand with legal entity details.
  2. Register a campaign with your use case, opt-in method and three sample messages.
  3. Assign number(s) to the campaign before sending traffic.

Example workflow (AT&T): Admin Portal → Enhanced Business SMS → 10DLC Registration → create brand → create campaign → assign numbers.

3) What consent and disclosure elements do carriers expect?
  • Proactive consent (documented opt-in) for non-consumer messaging.
  • Sender identity at the start where practical.
  • STOP/HELP keyword support.
  • Clear terms such as frequency and “message and data rates may apply”.
  • Risk-aware links; avoid public shorteners in first contact.
4) What types of content are restricted or prohibited?

Illegal content is never allowed. Categories like SHAFT, scams and get-rich-quick are prohibited. High-risk finance and aggressive claims face strict scrutiny. Review against the carrier code of conduct and CTIA guidance.

5) What is the difference between 10DLC, short code and toll-free SMS?
ChannelBest forProsConsiderations
10DLCLocal presence and two-wayRecognisable number; cost-effectiveRequires brand and campaign registration; content rules
Short codeHigh-volume national alertsVery high throughputMore expensive; longer approvals
Toll-free SMSSupport and notificationsNationwide reachVerification recommended; content rules still apply

On mobile we hide the comparison table to improve readability. All channels still require compliant content and sender practices.

6) Do I need STOP/HELP even for single-message interactions?
Single-message programmes may not display STOP/HELP in that one message, although systems must support those commands. This is reflected in CTIA guidance and carrier practice.
7) Can I use public link shorteners?
Avoid public shorteners in first contact. Use branded or first-party links tied to your business to reduce filtering risk.
8) What sample messages should I provide to TCR?
Provide three unique, accurate examples that match your use case, show brand identity and include opt-out language. Do not use generic templates you found online.
9) Will unregistered or non-compliant traffic be filtered?
Yes. Carriers use content and behaviour-based filtering, including machine-learning systems. Unregistered or deceptive content is more likely to be blocked or rate-limited.
10) What do carriers say about A2P channels?
Verizon recognises short code, toll-free and 10DLC as A2P channels on its public guidance. T-Mobile requires adherence to its Code of Conduct and CTIA Principles. AT&T publishes step-by-step TCR registration instructions for business products.

How to Register (Brand → Campaign → Numbers) #

  1. Brand: legal name, EIN/Tax ID, address and website.
  2. Campaign: use case selection, opt-in method with proof, three sample messages and STOP/HELP keywords.
  3. Assign numbers: link long codes to your campaign before sending.

Where to complete registration: check your carrier’s guidance and your messaging platform’s admin portal. Most businesses finish 10DLC registration inside their provider portal, which submits details to The Campaign Registry on your behalf.

  • T-Mobile: non-consumer messaging must follow the Code of Conduct and CTIA Principles. Policy overview
  • Verizon: A2P channels include short code, toll-free and 10DLC. Guidance page
  • AT&T (example): step-by-step brand, campaign and number assignment workflow. Registration tutorial
Tip: common places to find the 10DLC form in provider portals
  • Admin settings → Messaging or SMS
  • Compliance or Trust Centre
  • 10DLC/Brand & Campaigns → Create brand → Create campaign → Assign numbers

Keep screenshots and logs of your opt-in flow (timestamp, IP, form text and source) for audits and carrier reviews.

Compliant vs risky examples #

✅ Compliant first message

BrandName: Thanks for joining delivery alerts. Up to 4 msgs/mo. Msg&data rates may apply. Reply STOP to opt out, HELP for help.

❌ Risky first message

You are pre-approved - claim now: bit.ly/xxxx (no brand identity, public short link, implied finance claim and no STOP).

Test a message before you send

Run your SMS through our free compliance checker to reduce carrier filtering.

Check Now → Chrome Extension

Official references (Carriers and CTIA) #

  • T-Mobile: Non-consumer messaging must follow T-Mobile’s Code of Conduct and CTIA Principles. Policy overview.
  • Verizon: A2P can use short code, toll-free or ten-digit long code (10DLC). Guidance page.
  • AT&T (example product): Admin steps to set up TCR brand, campaign and number assignment. Registration tutorial.
  • CTIA: Messaging Principles & Best Practices (May 2023) and the monitoring handbook describe consent, HELP/STOP support and anti-spam measures. CTIA • Short Code Monitoring Handbook.