VIN: Check the checksum

The standard ISO 3779, which specifies the structure of the VIN vehicle, recommend placing in the 9th position of the VIN checksum (control number, verification number) – the number calculated on the algorithm defined by the standard, whose value depends on the values of all the other characters in the VIN. The checksum enables to counteract legalization of cars with wrong license plate numbers by car thieves (change of any of the digits in VIN shall change the checksum, but as a rule, thieves do not recalculate it) and to calculate wrong body numbers when entering them manually into databases. The standard in this part is mandatory only in the U.S. and Canada. Therefore, all vehicles intended for sale on the North American continent are required to have a check digit in the 9th position, which can be checked on this page. In Europe, this recommendation of the standard is not obligatory and manufacturers, as a rule, either use position 9 to indicate some additional characteristic of the car or put there a fixed sign: “0” (very popular with Japanese manufacturers) or “Z” (Volkswagen, Audi). But there are exceptions – BMW cars have an identical VIN structure regardless of the sales market.

In the case of the 9th position of the checksum, the following values are allowed there: numbers 0…9 or X. If any other character is in the 9th position, this VIN will not pass the check. If it is the VIN of the car meant for the North-American market, it was either copied from the car with errors or rewritten.

But beware of the fact that if the VIN contains a checksum, but the car was assembled from an SKD kit (especially true for “screwdriver assembly in the CIS countries), the VIN applied to the body becomes just a body number, and the assembler assigns his new VIN, which he puts on an additional plate on the body. In this case, most often the WMI (manufacturer identification code) in the “old” VIN is replaced by the code of the assembler and the remaining characters from 4 to 17 are transferred without change. That’s why in such VIN the checksum will not be calculated correctly – you have to take the “old” VIN and check it.

Example of checksum calculation:

  • let’s take VIN, for example JHMCM56557C404453, and fill in the table below:
Position VIN12345678CHK1011121314151617
  • Replace letters with numbers according to the table:
Numerical equivalent 12345678123457923456789
  • And fill in the table below, where for each VIN digit its “weight” is indicated:
Position VIN 1234567891011121314151617
Numerical equivalent18434565CHK73404453
  • Add up the products of each VIN character by its “weight”:
    18 + 87 + 46 + 35 + 44 + 53 + 62 + 510 + 79 + 38 + 47 + 06 + 45 + 44 + 53 + 32 = 368
  • Calculate the nearest smallest integer multiple of 11:
    368/11 = 33.5
    33 * 11 = 363
  • The difference between the result in step 5 and the nearest smallest integer multiple of 11 is written in the ninth digit of VIN:
    CHK = 368 – 363 = 5
    If CHK = 10, then “X” (Roman 10) is written in the 9th position of the VIN.

Other car brands:

VIN Decoder Acura Alfa Romeo Audi Bentley Bugatti Buick Cadillac Chery Chevrolet USA and KOREA Chrysler Citroen Daewoo Datsun Dodge Fiat Ford Google Great Wall Honda Hummer Hyundai Infiniti Jaguar Jeep Kia Lancia Land Rover and Range Rover Lexus Maserati Maybach Mazda MERCEDES-BENZ (commercial vehicles) MERCEDES-BENZ Mitsubishi Nissan OLDSMOBILE Opel PONTIAC Porsche Renault Saab Saturn Seat SKODA Subaru Tesla Toyota Volkswagen Volvo

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