VIN Validation RegEx

Question

I have written a VIN validation RegEx based on the http://en.wikipedia.org/wiki/Vehicle_identification_number but then when I try to run some tests it is not accepting some valid VIN Numbers.

My RegEx:

^[A-HJ-NPR-Za-hj-npr-z\\d]{8}[\\dX][A-HJ-NPR-Za-hj-npr-z\\d]{2}\\d{6}$

VIN Number Not Working:
1ftfw1et4bfc45903
WP0ZZZ99ZTS392124

VIN Numbers Working:
19uya31581l000000
1hwa31aa5ae006086

(I think the problem occurs with the numbers at the end, Wikipedia made it sound like it would end with only 6 numbers and the one that is not working but is a valid number only ends with 5)

Any Help Correcting this issue would be greatly appreciated!

Answer 1

I can't help you with a perfect regex for VIN numbers -- but I can explain why this one is failing in your example of 1ftfw1et4bfc45903:

^[A-HJ-NPR-Za-hj-npr-z\d]{8}[\dX][A-HJ-NPR-Za-hj-npr-z\d]{2}\d{6}$

Explanation:

• ^[A-HJ-NPR-Za-hj-npr-z\d]{8}
  This allows for 8 characters, composed of any digits and any letters except I, O, and Q; it properly finds the first 8 characters:
  1ftfw1et
• [\dX]
  This allows for 1 character, either a digit or a capital X; it properly finds the next character:
  4
• [A-HJ-NPR-Za-hj-npr-z\d]{2}
  This allows for 2 characters, composed of any digits and any letters except I, O, and Q; it properly finds the next 2 characters:
  bf
• \d{6}$
  This allows for exactly 6 digits, and is the reason the regex fails; because the final 6 characters are not all digits:
  c45903

Answer 2

Dan is correct - VINs have a checksum. You can't utilize that in regex, so the best you can do with regex is casting too wide of a net. By that I mean that your regex will accept all valid VINs, and also around a trillion (rough estimate) non-VIN 17-character strings.

If you are working in a language with named capture groups, you can extract that data as well.

So, if your goal is:

• Only to not reject valid VINs (letting in invalid ones is ok) then use Fransisco's answer, [A-HJ-NPR-Z0-9]{17}.

• Not reject valid VINs, and grab info like model year, plant code, etc, then use this (note, you must use a language that can support named capture groups - off the top of my head: Perl, Python, Elixir, almost certainly others but not JS): /^(?<wmi>[A-HJ-NPR-Z\d]{3})(?<vds>[A-HJ-NPR-Z\d]{5})(?<check>[\dX])(?<vis>(?<year>[A-HJ-NPR-Z\d])(?<plant>[A-HJ-NPR-Z\d])(?<seq>[A-HJ-NPR-Z\d]{6}))$/ where the names are defined at the end of this answer.

• Not reject valid VINs, and prevent some but not all invalid VINs, you can get specific like Pedro does.

• Only accept valid VINs: you need to write code (just kidding, GitHub exists).

Capture group name key:

• wmi - World manufacturer identifier
• vds - Vehicle descriptor section
• check - Check digit
• vis - Vehicle identifier section
• year - Model year
• plant - Plant code
• seq - Production sequence number

Answer 3

This regular expression is working fine for validating US VINs, including the one you described:

[A-HJ-NPR-Z0-9]{17}

Remember to make it case insensitive with flag i

Source: https://github.com/rfink/angular-vin