What Federal Rules Require Carriers to Carry in Wireless Alerts

Federal rule 47 CFR Part 10 requires a wireless carrier that chooses to participate in the Wireless Emergency Alerts (WEA) system to receive and transmit four specific classes of alerts, and it lets that carrier offer subscribers an opt-out for three of the four classes — but not for the top-priority National Alert class, which by rule preempts every other alert. Participation in WEA itself is voluntary for carriers in the first place.

This original record-reading guide is a general reading aid, not cited evidence. It does not depict a source record; the article text and source links provide the facts.

Key points

• A participating carrier must carry four alert classes: Presidential Alert, Imminent Threat Alert, Child Abduction Emergency/AMBER Alert, and Public Safety Message.
• Carriers may offer subscribers an opt-out only for three of those four classes: Child Abduction Emergency/AMBER Alert, Imminent Threat Alert, and Public Safety Message.
• National Alerts (the Presidential Alert class) cannot be opted out of and preempt all other Alert Messages.
• Each alert message is capped at 360 characters, with a 90-character minimum floor only on network elements that are technically incapable of the full length.
• WEA participation is a voluntary regulatory framework for carriers, not a mandate to join.

The four required alert classes

Under Part 10, “A Participating CMS Provider is required to receive and transmit four classes of Alert Messages: Presidential Alert; Imminent Threat Alert; Child Abduction Emergency/AMBER Alert; and Public Safety Message” (https://www.ecfr.gov/current/title-47/part-10). A carrier that has opted into the WEA system takes on all four classes as a baseline obligation.

The rule further defines the top class in its own paragraph: “paragraph (a) is titled ‘National Alert’ … defining it as ‘an alert issued by the President of the United States or the President’s authorized designee, or by the Administrator of FEMA’” (https://www.ecfr.gov/current/title-47/part-10).

Carrier opt-out classes

Part 10 draws a line between the National Alert class and the other three. It states that carriers “may provide their subscribers with the option to opt out of the ‘Child Abduction Emergency/AMBER Alert,’ ‘Imminent Threat Alert’ and ‘Public Safety Message’ classes” (https://www.ecfr.gov/current/title-47/part-10). The Presidential/National Alert class is not on that list, and the rule text says why: “National Alerts preempt all other Alert Messages” (https://www.ecfr.gov/current/title-47/part-10). No opt-out provision applies to that class.

Priority and message-length limits

Part 10 sets objective criteria that alerts must meet, expressed in Common Alerting Protocol terms: “Urgency must be ‘Immediate’ or ‘Expected’; Severity must be ‘Extreme’ or ‘Severe’; Certainty must be ‘Observed’ or ‘Likely’” (https://www.ecfr.gov/current/title-47/part-10).

On message size, the rule sets a “Maximum 360 characters; providers with technically incapable infrastructure may use 90 characters minimum on those network elements only” (https://www.ecfr.gov/current/title-47/part-10).

Participation is voluntary

The rule frames the entire system as opt-in for carriers: “The rules in this part establish the requirements for participation in the voluntary Wireless Emergency Alerts system” (https://www.ecfr.gov/current/title-47/part-10). A carrier that never joins WEA is not bound by Part 10’s four-class carriage requirement in the first place; the obligations described above apply only once a carrier has elected to participate.

Rule source and currency

Part 10 implements the “Warning, Alert, and Response Network Act, Title VI of the Security and Accountability for Every Port Act of 2006, Public Law 109-347” (https://www.ecfr.gov/current/title-47/part-10), first published in the Federal Register at “71 FR 36975, June 26, 2006” (https://www.ecfr.gov/current/title-47/part-10), with the current alert-class and opt-out framework dating to “73 FR 43117, July 24, 2008, as amended at 81 FR 75726, Nov. 1, 2016; 86 FR 46790, Aug. 20, 2021” (https://www.ecfr.gov/current/title-47/part-10). The eCFR page states it is “Displaying title 47, up to date as of 9/03/2026. Title 47 was last amended 9/03/2026” (https://www.ecfr.gov/current/title-47/part-10).

What this article does not cover

This article describes only what Part 10 requires a participating carrier to carry, opt out of, and prioritize. It does not address who is authorized to originate or send an alert in the first place — that question is governed by a separate rule, not Part 10. It does not claim that any specific alert is guaranteed to reach a specific phone; Part 10 itself allows carriers to use an approximated target area when their infrastructure cannot match the specified target area exactly. It does not walk through the device-level steps for turning alert categories on or off on a particular phone or carrier plan, since Part 10 only establishes that an opt-out may be offered for three classes, not how a carrier or device must implement it. And it does not offer guidance on what to do if you receive an alert; it covers only the regulatory text describing carrier obligations.

Source links

https://www.ecfr.gov/current/title-47/part-10 https://www.ecfr.gov/current/title-47/chapter-I/subchapter-A/part-10