The U.S. state of New Mexico first required its residents to register their motor vehicles and display license plates in 1912.
As of 2024[update], plates are issued by the New Mexico Taxation and Revenue Department through its Motor Vehicle Division.
In 1956, the United States, Canada and Mexico came to an agreement with the American Association of Motor Vehicle Administrators, the Automobile Manufacturers Association and the National Safety Council that standardized the size for license plates for vehicles (except those for motorcycles) at 6 inches (15 cm) in height by 12 inches (30 cm) in width, with standardized mounting holes.
[1] The 1955 (dated 1956) issue was the first New Mexico license plate that complied with these standards.
[2] New Mexico established a numeric county-code system for its passenger and truck plates in 1947.