Ever wonder just *what* all those letters and numbers in a vehicle identification number (VIN) actually mean? This article will discuss some of the history of VINs, outline what each of the characters tells us, and provide some commercial and online resources for VIN-decoding.
In the mid 1950's, as mass production of automobiles really took off, American car makers began stamping and casting numbers on cars and parts to help identify a vehicle's model and features, such a "vehicle identification number" came to be referred to as the "VIN". Before 1981 in the US, VIN format, length, and meaning was a mish-mash of whatever the manufacturer felt like putting on their cars, though some manufacturers used the standard 17-character format even in 1980. For these older vehicles, special look-up books are usually required for decoding. Lee Cole used to sell such books online but seems to have discontinued them, Mitchell's sold such a book in years gone by (Vehicle identification manual : 1969-78 domestic passenger cars, ASIN: 0847066088) but it appears to be out of print.
The first modern VIN standard was originally defined by the International Standards Organization (ISO) Standard 3779 in 1977, and revised in 1983. In the US, the guiding document is Part 565 of the 49th Code of Federal Regulations, which outlines exactly what those letters all stand for. In an all-too-rare exhibit of our tax-dollars doing something really useful, this document can usually be found online through the Government Printing Office website but sometimes their database is tangled up or otherwise misbehaving (as it was the day this article was written). If the GPO version is not working, a pdf-version of the 1997 edition of this document has been stored on this site at 49cfr565.pdf.
FORMAT and MEANING
All VINs have 17 characters, composed of capital letters A to Z and numbers 1 to 0, excluding the letters I, O, and Q, in order to avoid confusion. No signs or spaces are allowed. Each VIN contains three major sections: WMI, VDS, and VIS, as described below.
The first character of a WMI identifies a geographical region. For instance, a car made in Africa gets one of these letters: A, B, C, D, E, F, G, H. The table to the right shows the allotment of characters for each geographic region.
The second character identifies a particular country of origin. For instance, A through M indicate the United Kingdom, N through T indicate Germany, etc. See Toronto Transport Society's Page for a more complete list of letter/country assignments for each geographical area. In some cases, the first digit is essentially unique to a country of origin as well (for instance, 1=USA; 2=Canada; 3=Mexico; J=Japan).
The third character identifies a manufacturer, but a "9" means it's a company that builds fewer than 500 units per year. In these cases (and for some larger companies as well) the characters at positions 12, 13, and 14 are used as a suffix for the WMI, to further identify the manufacturer. For instance, "1B9" with the suffix "133" means the Buell Motorcycle Company, but "1B9" with the suffix "300" means Airstream. Quite often these suffix spaces are available for larger manufacturers to use as part of the sequential number for a particular model.
Information about a number of WMIs from various countries (including some VIN-decoder links for particular makes) can be found online at:
A fairly comprehensive table of WMI codes from autocalculator.org
The BIG NHTSA list in the form of a downloadable Microsoft-ACCESS database; includes over 23,000 WMIs from all over the world, with maker's names, addresses, and contact information.
VDS - Vehicle Description Section This section contains 6 characters (4th to 9th positions in VIN) and defines vehicle attributes specified by manufacturer. Typically, this section includes information on the type of restraint installed in the car (active, passive, airbags, etc), the body style, which type engine it came with, the GVWR, and what type of brake system it has, among other possibilities. The last character in this section is the "check digit". After all other characters in the VIN have been determined by the manufacturer the check digit is calculated by carrying out a mathematical computation specified in detail in 49CFR565, which assigns a numeric value to each letter, multiplies each of the 16 values by a "weighting factor," adds all the results, and then divides that value by 11. The remainder from this division process is the check digit, unless the remainder is 10, in which case the check digit is X. A good description of how to calculate the check digit can be found online at this Wiki Page.
VIS - Vehicle Identifier Section The tenth character of VIN defines the model year, per the table to the right, and don't forget that the model year can include units made as early as august the previous year! The cycle will repeat every 30 years, with 2011 being "1" again. The eleventh character defines the manufacturer plant, and the last 6 numbers form a sequential serial number for that particular vehicle. The last four characters are always numeric. The WMI suffix (discussed earlier) may fill positions 12, 13, 14, and the first two of those may be numbers or letters. The sequence doesn't have to start with 0001.
In our example, the X indicates it was a 1999 model year vehicle, the H indicates it was built in Alliston, Ontario, and the "567295" is the production sequence number. A quick Google search for the terms "Honda Civic Vin Decode" immediately netted several enthusiast's sites with a bunch of info on these cars.
Since 1997, the NHTSA Theft Prevention Standard requires manufacturers to include the VIN on various components of the car, so in addition to the normal position (on the dash and inside the door) you may find a VIN on the front and rear bumper, front fenders, hood, front and rear doors, and quarter panels, among other places. The label shown to the left here was inside the trunk deck lid of the Honda.
If your vehicle of interest is a type of car which has attracted enthusiasts, quite often this information can be found on particular makes or models online, but one has to take with a grain of salt anything sourced online, right? With that in mind, there are some sources generally considered to be more reliable than just any old webpage, and I've listed them below.
Next time you have to check a VIN, you'll be ready!
Carfax has a rudimentary VIN checker, but it doesn't tell you much about the car, it really wants to hook you into buying their title history information
NICB will provide anyone a Vin-check for Fraud/theft: VinCheck
A heavy-vehicle decoder is available from Gates
Members of the law enforcement community may obtain a copy of the NICB's VINassist by calling 708-237-4400 or 1-800-447-6282 extension 4400
Polk Automotive used to sell "VINA", but that seems to be gone now, instead they offer a decoder program as part of their larger software suite you have to pay for
The purveyors of Expert AutoStats also sell a VIN-Decoder, it costs $525, though annual update costs aren't described on their website:
VinLink is another commercial package with several options at various prices, geared towards programmers.
The Highway Loss Data Institute (which is connected with the Insurance Institute for Highway Safety) offers a program called VINdicator to its insurance company members. This package is apparently not available to the public.
Mechanical Forensics Engineering Services, LLC.
This page created 03-JAN-2003
and last modified 04-AUG-2020