Skip to content
Carfax Vin Check

VIN validator and check digit calculator

Type a VIN and see whether it holds together. Every step of the check-digit math is shown, and nothing leaves your browser.

0/17

What the check digit is

The ninth character of every VIN on a car sold in North America is a check digit. It's calculated from the other sixteen characters, so if any one of them is copied wrong, the numbers stop adding up. That's why it catches most typos, and why a VIN that fails the check is either mistyped or not what it claims to be.

How it's worked out

  1. Each letter is swapped for a number (A and J are 1, B and K are 2, and so on; digits stay as they are).
  2. Each of the 17 values is multiplied by a fixed weight for its position, from 8 down to 2, then 10, 0, 9 and down to 2 again.
  3. The products are added up and divided by 11.
  4. The remainder is the check digit. A remainder of 10 is written as X.

When a VIN fails

Read the VIN again from the car itself, not the listing: the plate at the base of the windshield or the door-jamb sticker. The usual culprits are 8 and B, 5 and S, 0 and D, and 1 and 7. If the VIN on the car and the one on the title both fail, or don't match each other, ask why before going any further.

VINs from outside North America often don't use a check digit, so a European or Japanese-market VIN can fail this test and still be genuine.