City of License - United States

United States

In the United States, the Communications Act of 1934 requires that “the Commission shall make such distribution of licenses, frequencies, hours of operation, and of power among the several States and communities as to provide a fair, efficient, and equitable distribution of radio service to each of the same.” The Federal Communications Commission interprets this as requiring that every broadcast station “be licensed to the principal community or other political subdivision which it primarily serves.” For each broadcast service, the FCC defines a standard for what it means to serve a community; for example, commercial FM radio stations are required to provide an electric field of at least 3.16 millivolts per meter (mV/m) over the entire land area of the community, whereas non-commercial educational FM stations need only provide a field strength of 1 mV/m over 50% of the community's population. This electric field contour is called the “principal community contour”.

The Federal Communications Commission (FCC) makes other requirements on stations relative to their communities of license; these requirements have varied over time. One example is the requirement for stations to identify themselves, by call sign and community, at sign-on, sign-off, and at the top of every hour of operation. Other current requirements include providing a local telephone number in the community's calling area (or else a toll-free number) and (in most cases) maintaining an official main studio within 25 miles of the community's geographic center.