US Business Messaging Rules: Where They Come From

Clients often ask where SMS/MMS compliance rules are published and who enforces them. There are three layers, and all three apply to every message your business sends.

Layer 1 — Federal law: the TCPA

The Telephone Consumer Protection Act (47 U.S.C. §227) and the FCC's implementing rules set the legal floor: prior express consent for automated texts (express written consent for marketing), the right to revoke consent by any reasonable means, and calling-time restrictions. Violations carry statutory damages per message, enforced through private lawsuits and the FCC.

Layer 2 — Industry standard: CTIA

The CTIA Messaging Principles & Best Practices is the playbook every US carrier holds senders to: consent expectations, STOP/HELP handling, prohibited content (SHAFT — sex, hate, alcohol, firearms, tobacco — plus gambling and illegal substances), and sender identification. Most message filtering traces back to a CTIA principle. See the other articles in this section for individual carrier codes of conduct.

Layer 3 — Channel registration regimes

• 10DLC (local numbers) — brands and campaigns register through The Campaign Registry and are reviewed before traffic flows. See the 10DLC section of this help center.
• Toll-free — numbers must pass Verified Sender review with the Toll-Free Messaging Registry; unverified toll-free numbers have been blocked since January 31, 2024. See the Toll-Free Verified Sender section.
• Short codes — programs are approved via a program brief and audited by CTIA on an ongoing basis. Highest throughput, highest scrutiny.

The consent and disclosure rules are the same across all three channels — what differs is who reviews your program, when, and how strictly. Registration is judged against the rules in force at review, and requirements tighten over time.

Last updated July 2026. Questions: TSG Global support.