What wikipedia says about this topic: “The U.S. state of California first required its residents to register their motor vehicles in 1905. Registrants had to provide their own license plates for display until 1914, when the state began to supply plates.
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 California license plate that complied with these standards. For more information, you can use this license plate lookup service.
License plates are currently issued by the California Department of Motor Vehicles.
Baseplates 1963 to present.
All base plates from 1963 to present are still valid for use, assuming the plate never left the vehicle and the vehicle maintained concurrent registration.
Modern standard issue automobile plates use a 7-digit format with a leading digit that remains constant plus a 6-digit serial starting with AAA000 and ending at ZZZ999. At that point the leading digit increases by one and the series starts over at AAA000. 6ZZZ999 was followed by 7AAA000, and should count up until the 1ABC123 series is exhausted at 9ZZZ999. At that point if the California DMV follows the precedent of reversing serial numbers at exhaustion as it has done since 1963, the next series should be in the 123ABC1 format.
Exclusions: The letters I, O, and Q are not used in the first or third alpha positions of the 7-digit alpha-numeric series.
The use of year-of-manufacture (YOM) plates is authorized by Section 5004.1 of the California Motor Vehicle Code. It is a law that allows vintage cars to be registered to use vintage license plates. Any officially manufactured California license plates which were produced prior to 1963 and plates on a currently registered vehicle or trailer of a corresponding model year. If used on the original plate, a sticker or metal tab that corresponds to the year of the vehicle is required.
In July, 2009, California extended its YOM program to include passenger vehicles from 1963-1969, and commercial vehicles (pick-ups, etc.) through 1972. Any black and gold plate from this era may be used on these vehicles, as long as they are “clear” with the DMV (i.e., not used, reported stolen, or no records found, for the last 10 years). A valid sticker must be attached to the plate corresponding to the year of the vehicle that is to be registered.
As of January, 2014, in very rare, select cases, California has extended custom license plates to exceed 7 digits, all the way up to, but not exceeding 9 characters.” Thanks for reading this interesting article. I would like to get your comments about the topic.