VIN Check Digit Validator
Instantly verify whether a 17-character VIN is authentic using the official 49 CFR 565 check-digit algorithm — right in your browser. Fastest way to catch a mistyped or tampered VIN before you decode or buy.
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Data sources
All the specs, recalls and safety data on VinSpecs are pulled from official public U.S. databases. We are an independent service, not affiliated with any government agency or manufacturer.
What the VIN check digit does: the 9th character of every North American VIN is a mathematical check digit derived from the other 16 characters. If a VIN is mistyped or tampered with, the calculated check digit won't match, a fast way to catch fraud or transcription errors before you decode or buy.
How the Check Digit Is Calculated
- Each letter is converted to a number (A=1, B=2 … using the official transliteration table); digits keep their value.
- Each value is multiplied by a position weight (8,7,6,5,4,3,2,10,0,9,8,7,6,5,4,3,2).
- All products are summed and divided by 11.
- The remainder is the check digit, where a remainder of 10 is written as the letter X.
Why It Matters When Buying a Used Car
A VIN with an invalid check digit is a red flag: it may be mistyped on a listing, or deliberately altered on a cloned or stolen vehicle. Always validate the check digit, then decode the VIN to confirm the vehicle's real specifications.
Frequently Asked Questions
What is the VIN check digit?
The 9th character of a VIN is a check digit, a number (0–9) or the letter X, calculated from the other 16 characters using a weighted formula defined in 49 CFR 565. It detects typos and tampering.
Does a valid check digit mean the VIN is real?
A valid check digit means the VIN is mathematically consistent and was likely transcribed correctly. To confirm the vehicle exists, decode the VIN against the NHTSA database.