A Vehicle Identification Number, commonly abbreviated to a VIN, is a number unique to each motor vehicle.

VINs were first used in 1954. Prior to this, there was no accepted standard for these numbers, so different manufacturers used different formats.

In 1981 the National Highway Traffic Safety Administration of the United States standardised the format. It required all over-the-road-vehicles sold to contain a 17-character VIN, which does not include the letters I (i), O (o), or Q (q) (to avoid confusion with numerals 1 and 0).