VIN number structure: understanding the 17 characters

The VIN (Vehicle Identification Number) is a unique 17-character alphanumeric code assigned to every vehicle produced worldwide since 1981. Defined by the ISO 3779 standard, it serves as a universal serial number for the automotive industry. Understanding its structure allows you to manually decode some of the information it contains -- but a VIN decoding API remains essential for obtaining the complete identification.

Overview of the 17 positions

The VIN is divided into three main sections:

• Positions 1-3: WMI (World Manufacturer Identifier) -- identifies the manufacturer and country of origin
• Positions 4-9: VDS (Vehicle Descriptor Section) -- describes the vehicle characteristics
• Positions 10-17: VIS (Vehicle Indicator Section) -- identifies the individual unit

Two characters are excluded from VINs to avoid visual confusion: the letter I (confused with the digit 1), the letter O (confused with the digit 0) and the letter Q (confused with 0 or O). The VIN therefore uses only 33 possible characters: digits 0-9 and letters A-Z except I, O and Q.

WMI: the world manufacturer code (positions 1-3)

The first three characters identify the manufacturer and its country of manufacture. The first character indicates the geographic zone:

• 1, 4, 5 -- North America (1 = United States, 2 = Canada, 3 = Mexico)
• J, K, L -- Asia (J = Japan, K = Korea, L = China)
• S-Z -- Europe (S = United Kingdom, V = France/Spain, W = Germany, Z = Italy)
• 6, 7 -- Oceania
• 8, 9 -- South America
• A-H -- Africa

The second and third characters identify the specific manufacturer. Here are some common WMIs for the European market:

• VF1 -- Renault (France)
• VF3 -- Peugeot (France)
• VF7 -- Citroen (France)
• WBA -- BMW (Germany)
• WDB -- Mercedes-Benz (Germany)
• WVW -- Volkswagen (Germany)
• WAU -- Audi (Germany)
• ZAR -- Alfa Romeo (Italy)
• ZFA -- Fiat (Italy)
• SJN -- Nissan (United Kingdom)
• TMB -- Skoda (Czech Republic)

For manufacturers producing fewer than 500 vehicles per year, the third character is fixed at 9 and additional positions (12-14) are used to identify the manufacturer.

VDS: the vehicle description (positions 4-9)

The VDS section describes the vehicle characteristics: body type, platform, engine, series. The encoding of this section is specific to each manufacturer, making manual decoding extremely difficult without knowledge of the manufacturer's internal tables.

The check digit (position 9)

In North America, position 9 is mandatorily a check digit calculated using a defined algorithm. This digit allows you to verify a VIN's validity and detect input errors. The algorithm assigns a numerical value to each character, multiplied by a positional weighting factor, then calculates the modulo 11 of the sum.

In Europe, position 9 is not necessarily a check digit -- it may be part of the vehicle description. This is one of the reasons why validating a European VIN is trickier than validating a North American one.

VIS: the individual identifier (positions 10-17)

Position 10: the model year

Position 10 encodes the model year according to a 30-year cycle. The most recent codes:

• M = 2021, N = 2022, P = 2023, R = 2024, S = 2025, T = 2026
• Note: the letters I, O, Q, U, Z and the digit 0 are not used in this position

It is important to note that the model year may differ from the actual manufacturing year. A vehicle produced in August 2025 may carry the 2026 model year code (T) if the manufacturer launched the new model year early.

Position 11: the assembly plant

The eleventh character identifies the plant where the vehicle was assembled. Each manufacturer assigns its own plant codes. For example, at Renault, F may designate the Flins plant and D the Douai plant.

Positions 12-17: the serial number

The last six characters form the sequential serial number. This is what makes each VIN unique worldwide. The combination of WMI, VDS and serial number ensures that no two vehicles share the same VIN.

Decoding example

Let us take a fictitious VIN: VF1RFA00867123456

• VF1 -- Renault, manufactured in France
• RFA008 -- vehicle description (Renault internal encoding)
• 6 -- control/description position
• 7 -- model year (per manufacturer table)
• 1 -- assembly plant
• 23456 -- sequential serial number

This partial decode illustrates the limits of manual interpretation: without Renault's internal tables, it is impossible to determine the exact model, engine or trim from the VDS. That is precisely what the AutomotivAPI VIN API does: it leverages those tables to return the complete vehicle identification.

Special cases and limitations

Some cases deserve attention:

• Vehicles before 1981 -- VINs could have fewer than 17 characters and did not follow a unified standard
• Reimported vehicles -- a vehicle built for a foreign market may have different VDS encoding from the version sold in France
• Recent manufacturers -- new manufacturers (Tesla, Rivian, NIO) have their own WMI codes assigned by national authorities
• Electric vehicles -- some VDS positions are reassigned to indicate battery capacity rather than displacement

For reliable and complete decoding, using a professional API is the only viable solution. Discover how to integrate the API into your application with our technical integration guide.