How to validate a VIN number? - php

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.

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

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));
}

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});
}

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.');
}
}

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.

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'));

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;
}
}