The U.S. state of Illinois first required its residents to register their motor vehicles in 1907. Registrants provided their own license plates for display until 1911, when the state began to issue plates. , plates are issued by the Illinois Secretary of State.
Front and rear plates are required on most vehicle types, with the exception of motorcycles, motor-driven cycles, and trailers. Plates were issued annually until 1979; multi-year plates have been issued ever since. Plates belong to vehicle owners, so they can be transferred from one vehicle to another.
Early history: 1907–1939
Automobile owners in Illinois were first required to register their vehicles with the Secretary of State's office in 1907, paying a one-time registration fee of $2. Registrants were issued a numbered aluminum disc to place on their dashboard, but they had to provide their own license plates. Annual registration commenced in 1909.
The state began to issue license plates in 1911. Front and rear plates were required each year, along with an aluminum dashboard disc whose number matched the serial on the plate. The legislation authorizing the state issuance of license plates also provided for the registration and plating of motorcycles, and issued special licenses and plates to mechanics and chauffeurs.
Serials were all-numeric and originally ran to five digits. When 99999 was reached in 1914 and 1915, serials with one letter and four digits were issued. Six-digit all-numeric serials were introduced in 1916, followed in 1925 by seven-digit serials. Aluminum dashboard discs were discontinued after 1917.
Trucks received their own plates for the first time in 1920. Serials on these plates were all-numeric until 1930, when weight codes were introduced. Trailers received their own plates from 1924 onwards.
In 1927, the state issued its first graphic license plate, featuring an embossed state shape to the right of the serial.
Mid-century history: 1940–1978
With the entry of the United States into World War II, and the subsequent introduction of measures to conserve metal for the war effort, Illinois manufactured its license plates for 1943 from wood-based fiberboard instead of steel. This practice continued each year up to and including 1948, despite the war ending in 1945 with the surrender of Japan. The state reverted to manufacturing its plates from steel in 1949, although the 1950 and 1951 plates were instead manufactured from aluminum.
License plates were placed under the jurisdiction of the Secretary of State in 1953. The 1954 plates were the first to feature the "Land of Lincoln" slogan, which continues to be used today.
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 in height by in width, with standardized mounting holes. The 1956 (dated 1957) issue was the first Illinois license plate that fully complied with these standards: the 1955 (dated 1956) issue was 6 inches in height by 12 inches in width, but had non-standard mounting holes.
Multiyear baseplates: 1979–present
In late 1966 the implementation of five year license plates, which would use renewal tabs annually, was proposed. Their use would also aid police in identifying drivers because the books that listed all license plate numbers were not available until halfway through the year. With fewer plate numbers changing, the books would be relevant for longer periods of time. Paul Powell, the Illinois Secretary of State, rejected the proposal stating that any cost savings would be minimized by additional record keeping costs. He also mentioned that some multiyear plates used in other states were not satisfactory. Powell further reiterated his position the following month by mentioning a University of Illinois study which recommended the annual change in license plate colors as an incentive for motorists to pay the annual registration cost, and that the initial cost of the longer term plates would be much more than regular plates. The University of Illinois study mentioned by Powell was conducted in 1957 and 1958, and also recommended the addition of letters to the Illinois license plate. In 1969 Powell backed a plan to implement two-year plates, which would have cost twice the annual registration price, but the plan did not pass the legislature.