Vehicle registration plates of Illinois

The U.S. state of Illinois first required motorists to register their vehicles in 1907 and began issuing license plates to registrants in 1911. Plates were issued annually until 1978.

In 1907, Illinois motorists were first required to register their vehicles with the Secretary of State's office and pay 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. The registration became annual in 1909 with motorists being issued aluminum dashboard discs and still had to provide their own license plates.

1911 was the first year that the state began issuing license plates itself. The aluminum dashboard discs were also issued, matching the license plate number. 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. Both plates and aluminum dashboard discs were issued annually.

By 1914, plates with letter prefixes (H, K, P, and R) were issued for the first time after reaching plate 99999 in order to keep the plates five characters. In 1916, the first six digit plates began to be issued. The next year, 1917, would be the final year of the issuance of the aluminum dashboard discs.

1920 marked the first year that plates were issued to different classes of vehicles. Only two general classes were specified, vehicles carrying less than seven people and those that carried more than seven people or carried freight. Trucks received their own special plate for the first time with a vertical "TRUCK" embossed onto the plate. Four years later, the first plates for trailers were issued.

In 1956, the U.S. states and Canadian provinces came to an agreement with the Automobile Manufacturers Association that standardized the size for license plates for vehicles, except those for motorcycles, at six inches in height by twelve inches in width, with standardized mounting holes. The 1955 (dated 1956) issue was the first Illinois license plate that complied with these standards.

The letters M (municipal), U (state owned), and W (disabled) are not used as prefixes on standard passenger plates.

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