Reading the 17-character code that tells a car's whole backstory
Stamped on every modern car is a string of 17 letters and digits that quietly records who built it, where, when and in what order. It never contains the letters I, O or Q, and one of its characters is a mathematical check that catches a mistyped code before it can cause trouble.
Vehicle identification numbers first appeared in the United States in 1954, but for over a decade every maker, and sometimes every division, did its own thing, and many codes were little more than serial numbers. From January 1966 the US government demanded a 13-character code, compulsory for all cars sold there by 1 January 1969, yet it only fixed the year, engine type and a six-digit number, leaving five spaces for manufacturers to fill as they pleased. In 1981 the National Highway Traffic Safety Administration imposed the 17-character format still used today, drawing on international standards issued in 1979 and 1980.
The code splits into three sections. The first three characters form the world manufacturer identifier, allocated by the Society of Automotive Engineers; the first usually signals the region, and within General Motors' 1G prefix, for instance, 1G1 meant Chevrolet cars and 1GC Chevrolet trucks. A maker building fewer than 1,000 vehicles a year puts a 9 in third place. Positions four to nine describe the vehicle, often using the eighth to mark the engine, and the ninth serves as a check digit that is compulsory in North America and China but not in Europe.
Positions 10 to 17 identify the individual machine. In North America the tenth encodes the model year: some firms used A for 1980, letters march on until Y means 2000, digits cover 2001 to 2009, and then the alphabet restarts. Because that repeats every 30 years, a 2008 rule tied position seven to the decoding for lighter vehicles, so a letter there points to 2010 to 2039. The eleventh marks the assembly plant, and the last six hold the production number.
Corporate history leaves fingerprints too. Opel and Vauxhall cars carried German prefixes while General Motors owned them, wherever they were assembled, and switched to French ones after joining PSA. The 2024 Lancia Ypsilon, from an Italian brand but made in Spain, carries French codes.
Source: Vehicle identification number
