manufacturers of other types of vehicles, has resulted in a drain on the supply of manufacturer
identifiers/WMIs available for large U.S. manufacturers.
The five characters in the second section (positions 4 through 8) of a VIN must identify
attributes of the specific type of vehicle involved. These attributes are indicated in Table I in
Part 565.15 (formerly 565.6).
The third VIN section consists of one character, called a check digit, in the ninth VIN
position. It reflects a calculation specified in Part 565 that is based on the other VIN characters
and that serves as a check against typographical errors in transcribing a VIN.
The fourth section consists of positions 10-17. The first two, positions 10 and 11, are for
the model year and plant of manufacture respectively. For large manufacturers, the last six
characters are used to sequentially number vehicles in groups of similar vehicles that are
manufactured by a given manufacturer. For manufacturers initially intending to produce fewer
than 500 vehicles of a given type, VIN positions 12, 13, and 14 are additional characters used for
the manufacturer’s manufacturer identifier. Under the current version of Part 565, this means
manufacturers that produce fewer than 500 vehicles of a given type have a six-digit manufacturer
identifier consisting of the first three positions of the 17-character VIN, with the third position in
practice always being a 9, and positions 12, 13, and 14. These small manufacturers use only the
last three digits of the VIN to sequentially number similar vehicles they produce.
When the current version of Part 565 went into effect beginning with the 1981 model
year, it was anticipated that the permutations available under the 17-character system described
in Part 565 would provide a sufficient number of unique VINs and manufacturer identifiers so
that, as required by Part 565, “the VINs of any two vehicles manufactured within a 30-year
period shall not be identical.”