VIN Decoded: A Position-by-Position Guide to Every Character

What the 17-Character Standard Means

Since 1981, the National Highway Traffic Safety Administration (NHTSA) has required all vehicles sold in the United States to carry a standardized 17-character Vehicle Identification Number (VIN). No two VINs assigned in the same calendar year are identical, making each one a unique fingerprint for a specific vehicle. The characters follow a rigid positional grammar — every digit or letter occupies a slot with a defined purpose.

Understanding that grammar lets you extract meaningful information from a VIN without any tool. For background on what a VIN is and where the standard originated, see what a VIN actually is. This guide focuses exclusively on position-by-position decoding.

The 17 characters are divided into three logical sections:

• Positions 1–3 — World Manufacturer Identifier (WMI)
• Positions 4–9 — Vehicle Descriptor Section (VDS)
• Positions 10–17 — Vehicle Identifier Section (VIS)

The letters I, O, and Q are never used in a VIN to prevent confusion with the numerals 1 and 0.

Positions 1–3: World Manufacturer Identifier (WMI)

The first three characters collectively form the World Manufacturer Identifier, assigned by SAE International (formerly the Society of Automotive Engineers) under an agreement with ISO standard 3779.

• Position 1 — Country of manufacture: A letter or digit that identifies the geographic region where the vehicle was assembled. For example, 1, 4, and 5 indicate the United States; 2 indicates Canada; 3 indicates Mexico; J indicates Japan; W indicates Germany.
• Position 2 — Manufacturer: Combined with Position 1, this character narrows identification to a specific automaker. For instance, 1G is General Motors (U.S.), while JT is Toyota (Japan).
• Position 3 — Vehicle type or division: Refines the manufacturer code to a division or vehicle category. Together, positions 1–3 uniquely identify the manufacturing entity responsible for the vehicle.

Manufacturers producing fewer than 500 vehicles per year receive a WMI ending in 9 at position 3, and positions 12–14 of the VIS then carry the true manufacturer code.

Positions 4–9: Vehicle Descriptor Section (VDS)

The six characters in the VDS are defined by the manufacturer — NHTSA sets the rules for what must be encoded here, but each automaker chooses how to arrange the specifics within those rules.

• Positions 4–8 — Vehicle attributes: These positions collectively describe the vehicle's platform characteristics, typically including body style (sedan, SUV, pickup), engine type and displacement, restraint systems (airbag configuration, seatbelt type), and GVWR (Gross Vehicle Weight Rating) for trucks. The exact order and meaning vary by manufacturer, which is why decoding these positions accurately requires a manufacturer-specific key.
• Position 9 — Check digit: This single character is mathematically derived from all other 17 characters using a formula established by NHTSA. It serves as a built-in authenticity verification — a computed value that reveals whether a VIN has been altered or fabricated. The check digit can be any numeral 0–9 or the letter X (representing 10).

For a practical walkthrough of reading these sections without software, reading a VIN plate manually provides step-by-step guidance.

Positions 10–17: Vehicle Identifier Section (VIS)

The final eight characters form the VIS, which functions like a serial number within a manufacturer's production run for a given year and plant.

• Position 10 — Model year: A single letter or digit encodes the model year using a standardized NHTSA table. For example, A = 1980, B = 1981 … Y = 2000, 1 = 2001 … 9 = 2009, A = 2010 (the cycle restarts). The letters I, O, Q, U, and Z are excluded from this table.
• Position 11 — Assembly plant: Identifies the specific factory where the vehicle was assembled. Each manufacturer defines its own plant codes, so the same letter can mean different plants at different automakers.
• Positions 12–17 — Production sequence number: A six-character serial number assigned sequentially on the assembly line. This is what makes each VIN unique within a model year and plant. For small-volume manufacturers (WMI ending in 9), positions 12–14 instead carry the manufacturer identifier, and only positions 15–17 are the true sequence.

Once you understand these positions, you can begin to see why VIN data connects to title and registration records. Explore how that works through VIN and title records, and see what history reports can surface via vehicle history reports.

Keep in mind that knowing how to decode a VIN is only the first step. For a clear picture of what that decoded data can — and cannot — tell you, see eight things a VIN can reveal.