vatChecker.php

<?php

class VATChecker {
	
	const RESPONSE_TIMEOUT = 5;

	const INVALID_COUNTRY_CODE = 1;
	const INVALID_FORMAT = 2;
	const UNABLE_TO_CHECK = 3;
	const VALID_VAT_NUMBER = 4;
	const INVALID_VAT_NUMBER = 5;
	
	
	private $countryCode;
	private $vatNumber;
	private $input;
	
	private $countrys = array(
		'AT' => '/ATU[0-9]{8}/',
		'BE' => '/BE0[0-9]{9}/',
		'BG' => '/BG[0-9]{9,10}/',
		'CY' => '/CY[0-9]{8}L/',
		'CZ' => '/CZ[0-9]{8,10}/',
		'DE' => '/DE[0-9]{9}/',
		'DK' => '/DK[0-9]{2}\s?[0-9]{2}\s?[0-9]{2}\s?[0-9]{2}/',
		'EE' => '/EE[0-9]{9}/',
		'EL' => '/EL[0-9]{9}/',
		'ES' => '/ES[A-Z0-9][0-9]{7}[A-Z0-9]/',
		'FI' => '/FI[0-9]{8}/',
		'FR' => '/FR[A-Z]{2}\s?[0-9]{9}/',
		'GB' => array('/GB[0-9]{3}\s?[0-9]{4}\s?[0-9]{2}/', 
					  '/GB[0-9]{3}\s?[0-9]{4}\s?[0-9]{2}\s?[0-9]{3}/', 
					  '/GB(HA|GD)[0-9]{3}/'),
		'HU' => '/HU[0-9]{8}/',
		'IE' => '/IE[0-9][A-Z0-9][0-9]{5}[A-Z]/',
		'IT' => '/IT[0-9]{11}/',
		'LT' => '/LT([0-9]{9,12})/',
		'LU' => '/LU[0-9]{8}/',
		'LV' => '/LV[0-9]{11}/',
		'MT' => '/MT[0-9]{8}/',
		'NL' => '/NL[0-9]{9}B[0-9]{2}/',
		'PL' => '/PL[0-9]{10}/',
		'PT' => '/PT[0-9]{9}/',
		'RO' => '/RO[0-9]{9}/',
		'SE' => '/SE[0-9]{12}/',
		'SI' => '/SI[0-9]{8}/',
		'SK' => '/SK[0-9]{10}/'
	);
	
	/**
	 * Constructor
	 * 
	 * Stores the countrycode and the actual VAT-number in the class
	 * variables.
	 * 
	 * @param string $vatNumber
	 */
	public function __construct($vatNumber)
	{
        // Set the default_socket_timeout
        ini_set('default_socket_timeout', VATChecker::RESPONSE_TIMEOUT);

		// Complete input
		$this->input = str_replace('.', '', $vatNumber);
		$this->input = strtoupper($this->input);
		
		// Country code
		$this->countryCode = strtoupper(substr($vatNumber, 0, 2));
		
		// Actual number
		$this->vatNumber = substr($vatNumber, 2, strlen($vatNumber));
	}
	
	/**
	 * isValid
	 * 
	 * Checks the validity of the VAT-number.
	 * 
	 * @return boolean
	 */
	public function isValid()
	{
		// Check if the country code exists
		if (!isset($this->countrys[$this->countryCode])) {
			return self::INVALID_COUNTRY_CODE;
		}
		
		// Store the regex or array of multiple regexes in local variable
		$regex = $this->countrys[$this->countryCode];
		
		// Match the input against the regexes
		if (is_array($regex)) {
			// Multiple regexes
			foreach ($regex as $regex) {
				if (!preg_match($regex, $this->input)) {
					return self::INVALID_FORMAT;
				}
			}
		} else {
			// Single regex
			if (!preg_match($regex, $this->input)) {
				return self::INVALID_FORMAT;	
			}
		}
		
		// Finally check if the number is actually valid
		// This has to be done with a SOAP request
		$client = new SoapClient('http://ec.europa.eu/taxation_customs/vies/checkVatService.wsdl');
		
		try {
			$response = $client->checkVat(array('countryCode' => $this->countryCode, 'vatNumber' => $this->vatNumber));
		} catch (SoapFault $e) {
			// In case of a timeout or any other error return false
			return self::UNABLE_TO_CHECK; 
		}
		
		if ($response->valid) {
			return self::VALID_VAT_NUMBER;
		} else {
			return self::INVALID_VAT_NUMBER;
		}
	}
}