In the U.S., license plates are issued by a department of motor vehicles or an agency of the state or territorial government. Some American Indian tribes also issue plates.
In 1956, the U.S. states and Canadian provinces came to an agreement with the Automobile Manufacturers Association that fixed the size of all passenger vehicle plates at 6 by 12 inches, although the dimensions may vary slightly by jurisdiction. In North America, only Saint Pierre and Miquelon have not adopted these standards. Smaller-sized plates are used for motorcycles and, in some jurisdictions, mopeds and certain types of trailers and construction equipment. Furthermore, the US Territory of Puerto Rico has a European sized specialty plate.
License plate designs often contain symbols, colors, or slogans associated with the issuing jurisdiction. Registration number formats, typically alphanumeric, are designed to provide enough unique numbers for all motor vehicles a jurisdiction expects to register.
In the U.S., many states distinguish their license plates through distinctive color schemes and logos, which persist over time. For example, the cowboy logo often associated with the state of Wyoming has appeared on that state’s license plates continuously since 1936. Some early Tennessee plates were produced in a parallelogram shape approximating that of the state.
Vermont license plates have frequently featured a green and white color scheme, while Alaska has preferred yellow and blue. Other states and provinces, such as California, offer simpler schemes, often with a white background and little decoration.
Florida, Georgia, Indiana, Maryland, Michigan, Nebraska, Pennsylvania, South Carolina, and West Virginia have placed the address of the state’s official or tourism web site on their general issue plates. Most plates in Washington, D.C. contain the phrase “Taxation without representation” to highlight the District’s lack of a voting representative in Congress.
As of May 2016, the three oldest plate designs in use – each with slight to moderate cosmetic changes since inception – are that of Delaware (in production since 1959), Colorado (since 1960, continuously since 1978), and Minnesota (since 1978).