Why are VINs exactly 17 characters?

The 17-character length was standardized in 1981 by ISO 3779. This length provides enough space to encode all necessary information while remaining manageable. All vehicles manufactured after 1981 must have a 17-character VIN.

Why can't VINs contain I, O, or Q?

The letters I, O, and Q are excluded from VINs to prevent confusion with the numbers 1 and 0. This reduces errors when VINs are read or transcribed manually.

How do you know which year a year code represents?

Year codes cycle every 30 years. For example, 'A' represents both 1980 and 2010. Context clues help determine the correct year: vehicle age, manufacturer history, and other VIN positions. Modern vehicles (2010+) typically use the more recent year in the cycle.

What is the purpose of the check digit?

The check digit validates the VIN's integrity. If any character is changed, the check digit will no longer match, indicating an error or potential fraud. This is especially important for vehicle registration, insurance, and law enforcement.

Why do manufacturers have multiple WMI codes?

Manufacturers often have multiple WMI codes because they manufacture vehicles in different countries or regions. For example, Toyota has different WMI codes for vehicles made in Japan, the US, Canada, and other countries. Some manufacturers also use different codes for different vehicle types or brands.

Where can I find my vehicle's VIN?

VINs are typically found in several locations: driver's side dashboard (visible through windshield), driver's side door jamb, vehicle registration documents, insurance card, vehicle title, and engine block (some vehicles).

Complete VIN Reference Guide

Vehicle Identification Number (VIN) Guide

Everything you need to know about VINs: structure, decoding, WMI codes, manufacturer lookup, year codes, and validation. Perfect for developers, vehicle owners, and enthusiasts.

Decode a VIN Generate VINs

174

Manufacturers

649

WMI Codes

Countries

1980-2039

Year Range