How to validate a VIN number?

Question

How can I validate a Vehicle Identification Number with PHP? I just need to check if the entered VIN number is correct or not.

Dickenson

Vehicle Identification Number ? – Dripstone

Please define "VIN". This is an international community, and acronyms are seldom unique in their meaning across the globe – Winegrower

It depends on exactly which VIN you are talking about. There are ISO and European versions; there are also versions for quantities of <500 and >=500, all of which have different validation procedures. – Shingles

en.wikipedia.org/wiki/… gives a fairly sufficient step by step procedure to calculate a VIN checkdigit. This should give you enough info to write a validate procedure. – Buine

In case anyone comes across this (as I did today), vpic.nhtsa.dot.gov/api supplies vin lookups free. – Monostich

VIN number y redundant, VIN means Vehicle Identification Number as is. – Isaacs

Answer 1

Here's something I wrote up real quick using the example in the wikipedia article.

Not guaranteed perfect or bug free or super efficient, but should provide you with a solid starting point:

Note: I included the edits provided by Confluence below, making the procedure slightly more succinct.

function validate_vin($vin) {

    $vin = strtolower($vin);
    if (!preg_match('/^[^\Wioq]{17}$/', $vin)) { 
        return false; 
    }

    $weights = array(8, 7, 6, 5, 4, 3, 2, 10, 0, 9, 8, 7, 6, 5, 4, 3, 2);

    $transliterations = array(
        "a" => 1, "b" => 2, "c" => 3, "d" => 4,
        "e" => 5, "f" => 6, "g" => 7, "h" => 8,
        "j" => 1, "k" => 2, "l" => 3, "m" => 4,
        "n" => 5, "p" => 7, "r" => 9, "s" => 2,
        "t" => 3, "u" => 4, "v" => 5, "w" => 6,
        "x" => 7, "y" => 8, "z" => 9
    );

    $sum = 0;

    for($i = 0 ; $i < strlen($vin) ; $i++ ) { // loop through characters of VIN
        // add transliterations * weight of their positions to get the sum
        if(!is_numeric($vin{$i})) {
            $sum += $transliterations[$vin{$i}] * $weights[$i];
        } else {
            $sum += $vin{$i} * $weights[$i];
        }
    }

    // find checkdigit by taking the mod of the sum

    $checkdigit = $sum % 11;

    if($checkdigit == 10) { // checkdigit of 10 is represented by "X"
        $checkdigit = "x";
    }

    return ($checkdigit == $vin{8});
}

Note: there is a small percent error with verifying VINs because of the nature of the checksum:

...a match does not prove the VIN is correct, because there is still a 1 in 11 chance of any two distinct VINs having a matching check digit.

Also note: 11111111111111111 will validate against the procedure above. Whether or not you want to check for that is up to you:

Straight-ones (seventeen consecutive '1's) will suffice the check-digit. This is because a value of one, multiplied against 89 (sum of weights), is still 89. And 89 % 11 is 1, the check digit. This is an easy way to test a VIN-check algorithm.

reference: http://en.wikipedia.org/wiki/Vehicle_identification_number#Check_digit_calculation

Buine

respect for going as far as to whip something up to this extent. +5 if I could. – Deuterogamy

I have a Discrete Math/Algorithms exam in about 30 minutes, figured it wouldn't hurt to get my mind rolling. : ) – Buine

@Confluence the exam was far simpler than I had anticipated: mostly just analyzing time complexity of various algorithms... and thanks for the edit! Programming before noon has never been my strong suit... – Buine

Take into consideration that some other old vehicles have different VIN length. This are the vehicles produced prior to model year 1981. Source dataone – Isaacs

Answer 2

Here's a version of the code by jordan ported to Javascript, hope it's helpful to someone...

function validate_vin(vin)
{
  function isnumeric(mixed_var) {
    return (typeof(mixed_var) === 'number' || typeof(mixed_var) === 'string') && mixed_var !== '' && !isNaN(mixed_var);
  }
  var pattern = /^[^\Wioq]{17}$/;
  var weights = Array(8, 7, 6, 5, 4, 3, 2, 10, 0, 9, 8, 7, 6, 5, 4, 3, 2);
  var transliterations = {
    "a" : 1, "b" : 2, "c" : 3, "d" : 4,
    "e" : 5, "f" : 6, "g" : 7, "h" : 8,
    "j" : 1, "k" : 2, "l" : 3, "m" : 4,
    "n" : 5, "p" : 7, "r" : 9, "s" : 2,
    "t" : 3, "u" : 4, "v" : 5, "w" : 6,
    "x" : 7, "y" : 8, "z" : 9
  };

  vin = vin.toLowerCase();
  if(!vin.match(pattern)) { return false; }

  var sum = 0;
  for(var i=0; i<vin.length; i++) {
    if(!isnumeric(vin.charAt(i))) {
      sum += transliterations[vin.charAt(i)] * weights[i];
    } else {
      sum += parseInt(vin.charAt(i)) * weights[i];
    }  
  }

  var checkdigit = sum % 11;
  if(checkdigit == 10) { // check digit of 10 represented by X
    checkdigit = 'x';
  }

  return (checkdigit == vin.charAt(8));
}

Impeachable

Answer 3

It's "VIN." "VIN Number" = "Vehicle Identification Number Number," which doesn't make sense.

You can see a definition of the structure of VINs here:
http://en.wikipedia.org/wiki/Vehicle_identification_number

And you can work from there, or you can grab this script here:
http://www.geekpedia.com/code29_Check-if-VIN-number-is-valid.html

---

Here is an improved version of the function posted by jordan:

$vin = "1M8GDM9AXKP042788";

function validate_vin($vin) {

    $vin = strtolower($vin);
    if (!preg_match('/^[^\Wioq]{17}$/', $vin)) { 
        return false; 
    }

    $weights = array(8, 7, 6, 5, 4, 3, 2, 10, 0, 9, 8, 7, 6, 5, 4, 3, 2);

    $transliterations = array(
        "a" => 1, "b" => 2, "c" => 3, "d" => 4,
        "e" => 5, "f" => 6, "g" => 7, "h" => 8,
        "j" => 1, "k" => 2, "l" => 3, "m" => 4,
        "n" => 5, "p" => 7, "r" => 9, "s" => 2,
        "t" => 3, "u" => 4, "v" => 5, "w" => 6,
        "x" => 7, "y" => 8, "z" => 9
    );

    $sum = 0;

    for($i = 0 ; $i < strlen($vin) ; $i++ ) { // loop through characters of VIN
        // add transliterations * weight of their positions to get the sum
        if(!is_numeric($vin{$i})) {
            $sum += $transliterations[$vin{$i}] * $weights[$i];
        } else {
            $sum += $vin{$i} * $weights[$i];
        }
    }

    // find checkdigit by taking the mod of the sum

    $checkdigit = $sum % 11;

    if($checkdigit == 10) { // checkdigit of 10 is represented by "X"
        $checkdigit = "x";
    }

    return ($checkdigit == $vin{8});
}

Kilah

Apologies, I meant Vehicle Identification number. – Dickenson

Nissan has provided us with a vin number (JN1GANR35U0100001) which fails this validation. Is there a different calculation for US or EUROPE cars? – Dickenson

Even though "VIN Number" is a redundancy (and technically incorrect), it's still common to refer to them as "VIN numbers" in both speech and writing. It's the same with "PIN Number" or "ATM Machine". – Imperceptible

That's called "pleonasm", also known as "RAS syndrome". – Katzen

Answer 4

I recently had to write a VIN validation class with PHP. I posted my class for everyone to use at: http://dev.strategystar.net/2012/05/validate-vin-checksum-with-php/

class VIN
{
    public static $transliteration = array(
        'A'=>1, 'B'=>2, 'C'=>3, 'D'=>4, 'E'=>5, 'F'=>6, 'G'=>7, 'H'=>8, 
        'J'=>1, 'K'=>2, 'L'=>3, 'M'=>4, 'N'=>5, 'P'=>7, 'R'=>9,
        'S'=>2, 'T'=>3, 'U'=>4, 'V'=>5, 'W'=>6, 'X'=>7, 'Y'=>8, 'Z'=>9,
    );

    public static $weights = array(8,7,6,5,4,3,2,10,0,9,8,7,6,5,4,3,2);

    /***
     * The checksum method is used to validate whether or not a VIN is valid
     * It will return an array with two keys: status and message
     * The "status" will either be boolean TRUE or FALSE
     * The "message" will be a string describing the status
     */
    public static function checksum($vin)
    {
        $vin = strtoupper($vin);
        $length = strlen($vin);
        $sum = 0;

        if($length != 17)
        {
            return array('status'=>false, 'message'=>'VIN is not the right length');
        }

        for($x=0; $x<$length; $x++)
        {
            $char = substr($vin, $x, 1);

            if(is_numeric($char))
            {
                $sum += $char * self::$weights[$x];
            }
            else
            {
                if(!isset(self::$transliteration[$char]))
                {
                    return array('status'=>false, 'message'=>'VIN contains an invalid character.');
                }

                $sum += self::$transliteration[$char] * self::$weights[$x];
            }
        }

        $remainder = $sum % 11;
        $checkdigit = $remainder == 10 ? 'X' : $remainder;

        if(substr($vin, 8, 1) != $checkdigit)
        {
            return array('status'=>false, 'message'=>'The VIN is not valid.');
        }

        return array('status'=>true, 'message'=>'The VIN is valid.');
    }
}

Thoma

Answer 5

Note that the wiki says: "A check-digit validation is used for all road vehicles sold in the United States and Canada."

So if you're working with other countries you might want to loosen the check-digit validation

https://www.olschimke.eu/2012/08/02/dealing-with-vehicle-identification-numbers-vin-data-quality/ had some good tips.

Suwannee

is there a way to validate a VIN from say... Mexico? – Howitzer

Answer 6

Thanks to all for the algorithm etc. which I see is on Wikipedia. This is the version I put together based on the comments above. Note, there are problems with the versions above, for ex this 00000000000354888 returns OK for a vin. I took what was above and added an option to check year first if <1980, assume it isn't a 17digit real vin (have to), and also if there are sequences of a single character, assume invalid. This is good enough for my needs as I am comparing against values that are filled with 0s if not 17 in length. Also I know the year value so if I check that I can speed up the code by skipping the vin check (yes I could have put that in before the function) lol bye!.

  <?php
  /*
  =======================================================================================
  PURPOSE: VIN Validation (Check-digit validation is compulsory for all road vehicles sold in North America.)
  DETAILS: Validates 17 digit VINs by checking their formatting
  USAGE:  returns boolean or returns an array with a detailed message
  COMMENTS: This could be made more robust by checking the country codes etc..
  MORE INFO: https://en.wikipedia.org/wiki/Vehicle_identification_number
  =======================================================================================
  */

  class vinValidation {

public static $transliteration = array(
    'A'=>1, 'B'=>2, 'C'=>3, 'D'=>4, 'E'=>5, 'F'=>6, 'G'=>7, 'H'=>8,
    'J'=>1, 'K'=>2, 'L'=>3, 'M'=>4, 'N'=>5, 'P'=>7, 'R'=>9,
    'S'=>2, 'T'=>3, 'U'=>4, 'V'=>5, 'W'=>6, 'X'=>7, 'Y'=>8, 'Z'=>9,
);

public static $weights = array(8,7,6,5,4,3,2,10,0,9,8,7,6,5,4,3,2);

public function validateVIN($vin, $ret_array_status = false, $year = null) {

    //validates US/NA 1980>= VINs, if before 1980, no vin standards, this returns false
    if (!empty($year) && preg_match("/^[0-9]{4}/", $year)) {
        if ($year < 1980) return ($ret_array_status ? array('status' => false, 'message' => 'Unable to check VIN, pre-dates 1980.') : false);
    }

    $vin_length = 17; // US vin requirements >= 1980
    $vin = strtoupper(trim($vin));
    $sum = 0;

     //if (!preg_match('/^[^\Wioq]{17}$/', $vin))
    //return ($ret_array_status ? array('status'=>false, 'message'=>'VIN is not valid, not the right length.') : false);

    if (!preg_match('/^[A-HJ-NPR-Z0-9]{17}$/', $vin))
    return ($ret_array_status ? array('status'=>false, 'message'=>'VIN is not valid, VIN formatting is incorrect.') : false);

    if (preg_match('/(\w)\1{5,}/', $vin))
    return ($ret_array_status ? array('status'=>false, 'message'=>'VIN contains invalid repeating character sequence.') : false);

    for($x=0; $x < $vin_length; $x++) {
        $char = substr($vin, $x, 1);
        if(is_numeric($char)) {
            $sum += $char * self::$weights[$x];
        } else {
            if(!isset(self::$transliteration[$char]))
            return ($ret_array_status ? array('status'=>false, 'message'=>'VIN contains an invalid character.') : false);
            $sum += self::$transliteration[$char] * self::$weights[$x];
        }
    }
    $remainder = $sum % 11;
    $checkdigit = $remainder == 10 ? 'X' : $remainder;

    //echo " sum:".$sum." remain:".$remainder." check dig:".$checkdigit."\n";

    if(substr($vin, 8, 1) != $checkdigit)
    return ($ret_array_status ? array('status'=>false, 'message'=>'The VIN is not valid, failed checksum.') : false);

    // all is good return true or a value and status.
    return ($ret_array_status ? array('status'=>true, 'message'=>'The VIN is valid, passed checksum.') : true);
}


  }

TESTING :

  $vinClass = new vinValidation();

  // not long enough not val
  var_dump($vinClass->validateVIN('1I345678123456789', false, 2000));
  var_dump($vinClass->validateVIN('1I345678123456789'));

  echo "-----------------------------------------------------------\n";
  // not valid
  var_dump($vinClass->validateVIN('00000000012870842', true));
  var_dump($vinClass->validateVIN('00000000012870842', 1968)); //assumes faulty by year
  var_dump($vinClass->validateVIN('00000000012870842'));

  echo "-----------------------------------------------------------\n";
  // not valid
  var_dump($vinClass->validateVIN('00000000000354888', true));
  var_dump($vinClass->validateVIN('00000000000354888'));

  echo "-----------------------------------------------------------\n";
  // Fails Checksum test
  var_dump($vinClass->validateVIN('368TU79MXH4763452',false,2000));
  var_dump($vinClass->validateVIN('368TU79MXH4763452'));

  echo "-----------------------------------------------------------\n";
  // yachtzee, (returns true or array) !
  var_dump($vinClass->validateVIN('WP1AF2A56GLB91679',true));
  var_dump($vinClass->validateVIN('WP1AF2A56GLB91679'));

Restrain

Answer 7

Here is the JavaScript class version as posted by Mike Q:

class VIN {
    static transliteration = {
        'A':1, 'B':2, 'C':3, 'D':4, 'E':5, 'F':6, 'G':7, 'H':8, 'J':1, 'K':2, 'L':3, 'M':4, 'N':5, 'P':7, 'R':9, 'S':2, 'T':3, 'U':4, 'V':5, 'W':6, 'X':7, 'Y':8, 'Z':9
    }

    static weights = [8,7,6,5,4,3,2,10,0,9,8,7,6,5,4,3,2];

    validateVIN(vin, retArrayStatus = false, year = null) {

        if (year != null && year.match(/^[0-9]{4}/)) {
            if (year < 1980)
                return retArrayStatus ? {'status': false, 'message': 'Unable to check VIN, pre-dates 1980.'} : false;
        }

        let vinLength = 17;
        vin = vin.trim();
        let sum = 0;

        if (!vin.match(/^[A-HJ-NPR-Z0-9]{17}$/))
            return retArrayStatus ? {'status': false, 'message': 'VIN is not valid, VIN formatting is incorrect [i, o, q].'} : false;

        //if (!vin.match(/(\w)\1{5,}/))
        //    return retArrayStatus ? {'status': false, 'message': 'VIN contains invalid repeating character sequence.'} : false;

        for (let x = 0; x < vinLength; x++) {
            let char = vin.substr(x, 1);
            if (!isNaN(char)) {
                sum += char * VIN.weights[x];
            }
            else {
                if (VIN.transliteration[char] == '')
                    return retArrayStatus ? {'status': false, 'message': 'VIN contains an invalid character.'} : false;
                sum += VIN.transliteration[char] * VIN.weights[x];
            }
        }
        let reminder = sum % 11;
        let checkdigit = reminder == 10 ? 'X' : reminder;

        if (vin.substr(8, 1) != checkdigit)
            return retArrayStatus ? {'status': false, 'message': 'The VIN is not valid, failed checksum.'} : false;

        return retArrayStatus ? {'status': true, 'message': 'The VIN is valid, passed checksum.'} : true;
    }
}

Jar

Answer 8

Really liked bimbom22 code but after php 8.1.18 update throws this error: PHP Fatal error: Array and string offset access syntax with curly braces is no longer supported

Here is the updated syntax to address the Fatal error at php 8.1.18

function validate_vin($vin) {
    $vin = strtolower($vin);
    if (!preg_match('/^[^\Wioq]{17}$/', $vin)) { 
        return false; 
    }
    $weights = array(8, 7, 6, 5, 4, 3, 2, 10, 0, 9, 8, 7, 6, 5, 4, 3, 2);
    $transliterations = array(
        "a" => 1, "b" => 2, "c" => 3, "d" => 4,
        "e" => 5, "f" => 6, "g" => 7, "h" => 8,
        "j" => 1, "k" => 2, "l" => 3, "m" => 4,
        "n" => 5, "p" => 7, "r" => 9, "s" => 2,
        "t" => 3, "u" => 4, "v" => 5, "w" => 6,
        "x" => 7, "y" => 8, "z" => 9
    );
    $sum = 0;
    for($i = 0 ; $i < strlen($vin) ; $i++ ) { // loop through characters of VIN
        // add transliterations * weight of their positions to get the sum
        $check_char = substr($vin, $i, 1);
        if(!is_numeric($check_char)) {
            $sum += $transliterations[$check_char] * $weights[$i];
        } else {
            $sum += $check_char * $weights[$i];
        }
    }

    // find checkdigit by taking the mod of the sum
    $checkdigit = $sum % 11;
    if($checkdigit == 10) { // checkdigit of 10 is represented by "X"
        $checkdigit = "x";
    }
    $actual_checkdigit = substr($vin, 8, 1);
    return ($checkdigit == $actual_checkdigit);
}

Lawana