Overview #

The CTIA Messaging Principles and Best Practices outline how to maintain trusted messaging across the U.S. wireless ecosystem. They emphasize consumer protection, clear sender identity, and responsible application-to-person (A2P) communication.

For a step-by-step guide see our SMS Compliance Checklist and What is 10DLC?. You can also test a message in seconds.

The official CTIA Messaging Principles and Best Practices serve as industry guidance and complement—rather than replace—legal requirements such as TCPA, CAN-SPAM, and FCC rules.

  • Obtain explicit, program-specific opt-in and keep a record of when, where, and how consent was captured.
  • Send a confirmation that includes the brand name, message frequency, cost notice, and opt-out instructions.
  • Do not buy, rent, or share opt-in lists.
Example CTA: “Text JOIN to 12345 to get weekly tips from BrandName. Msg&data rates may apply. Up to 4 msgs/mo. Reply STOP to opt out.”

Identity and transparency #

  • Identify the sender in the message body using the brand or program name.
  • Use domains that reflect your brand and avoid public link shorteners in initial outreach.
  • If you include a phone number, it should clearly connect to the identified entity.

Opt-out and help keywords #

  • Support STOP, UNSUBSCRIBE, and CANCEL to end messages promptly.
  • Support HELP to return assistance or contact information.
  • Honor opt-outs across the program quickly and maintain clean lists.

Content standards #

  • Avoid deceptive, illegal, or harmful content and follow carrier codes for restricted categories.
  • Share accurate offer terms and avoid misleading claims or hidden conditions.
  • Do not snowshoe (spreading traffic across numbers to evade controls) and avoid unauthorized routes.

Numbers and provisioning #

  • Only text-enable numbers you are authorized to use and keep assignment records.
  • Monitor shared or proxy numbers closely for abuse.
  • Remove deactivated numbers promptly to reduce complaints.

Mitigating unwanted messaging #

  • Providers should filter clearly unwanted traffic and support spam reporting such as 7726 (“SPAM”).
  • Track complaint rates, bounces, and opt-outs and adjust sending accordingly.

Examples #

Promotional offer (compliant)

“BrandName: 20% off this week only at brand.com/sale. Up to 4 msgs/mo. Reply STOP to opt out.”

Security alert (transactional)

“BrandName: New sign-in from a new device. If this was you, no action needed. Reply HELP for support.”

Test a message before you send

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

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Further Reading: CTIA and Carrier Compliance

Learn more about A2P 10DLC messaging compliance by reviewing the official CTIA publication and understanding how carriers apply these principles. Staying current with CTIA and carrier policies helps keep your SMS campaigns trusted, transparent, and compliant.

  • CTIA Messaging Principles and Interoperability: www.ctia.org
    The core guide that outlines accepted messaging practices, interoperability standards, and consumer protection expectations.
  • T-Mobile: Focuses on proactive registration, restricted-content filtering, and required opt-out support for A2P programs.
  • AT&T: Emphasizes campaign-registration accuracy, clear brand identification, and transparent sender communication.
  • Verizon: Highlights consistent sender identity, timely opt-out processing, and prevention of deceptive or high-risk content.

For additional help with compliance see our related guides SMS Compliance Checklist and What Is 10DLC?.