The Federal Communications Commission’s (“FCC’s” or “Commission’s”) new text-to-911 rules are effective today. As we discussed in a previous post immediately following the adoption of the related order, the FCC has mandated that all messaging services that permit users to send text messages using domestic telephone numbers also enable users to communicate with public emergency response providers via text messages. The FCC adopted its Second Report and Order and Third Notice of Proposed Rulemaking in the Text-to-911 proceeding on August 8, 2014. On September 16, the order and NPRM were published in the Federal Register making the rules effective today and setting the comment deadline on the NPRM for today, with reply comments due on November 17. The new rules apply to all Commercial Mobile Radio Service (“CMRS”) providers, but also to over-the-top (“OTT”) messaging services. The Commission defines text messaging as “any service that allows a mobile device to send information consisting of text to other mobile devices using domestic telephone numbers,” including Short Messaging Service (“SMS”), Multimedia Messaging Service (“MMS”), and “two-way interconnected text applications.” So-called “interconnected text applications” refers to those services that enable customers to “send text messages to, and receive text messages from, all or substantially all text-capable U.S. telephone numbers.” Applications without this capability fall into the category of “non-interconnected apps.” Covered services must be technically capable of routing 911 texts by December 31, 2014, and must begin routing texts to emergency responders by June 30, 2015, or within six months of a request by a PSAP – whichever comes later. The Second Report and Order restricts the text-to-911 implementation mandate to interconnected messaging apps. However, the FCC has claimed that according to the Twenty-First Century Communications and Video Accessibility Act (“CVAA”) – the primary basis of asserted authority to impose the text-to-911 rules – the agency can apply regulations to all “advanced communications services” (ACS), a category that includes non-interconnected text services. In the NPRM, the Commission seeks comment on expanding its text-to-911 requirements to services including non-interconnected text services, real-time text applications, messages sent via WiFi, and rich-media services. It also seeks comment on issues regarding enhanced location information for texts to 911 and roaming. Wireless providers and messaging application owners, operators, and developers – even those whose services fall outside the purview of the new rules – should continue to pay close attention to these changes in communications regulations.