Simple PHP method to validate vatNumbers for a limited number of extra-EU and all the EU countries

vat-number-validator.php

private const COUNTRY_VALIDATION_PATTERNS = [
    'AL' => '[JKL]\d{8}[A-Z]',
    'AT' => 'U[\d]{8}',
    'AU' => '\d{11}',
    'BE' => '\d{10}',
    'BG' => '\d{9,10}',
    'BY' => '\d{9}',
    'CA' => '\d{9}',
    'CH' => '\d{3}\.\d{3}\.\d{3}',
    'CY' => '\d{8}[A-Z]',
    'CZ' => '\d{8,10}',
    'DE' => '\d{9}',
    'DK' => '\d{8}',
    'EE' => '\d{9}',
    'EL' => '\d{9}',
    'ES' => '([A-Z]\d{7}[A-Z]|\d{8}[A-Z]|[A-Z]\d{8})',
    'FI' => '\d{8}',
    'FR' => '[A-HJ-NP-Z\d]{2}\d{9}',
    'GB' => '(\d{9}|\d{12}|(GD|HA)\d{3})',
    'HR' => '\d{11}',
    'HU' => '\d{8}',
    'IE' => '(\d{7}[A-Z]|\d[A-Z]\d{5}[A-Z]|\d{7}[A-Z]{2})',
    'ID' => '\d{2}\.\d{3}\.\d{3}\.\d-\d{3}\.\d{3}',
    'IL' => '\d{9}',
    'IN' => '\d{15}',
    'IS' => '\d{5,6}',
    'IT' => '\d{11}',
    'KZ' => '\d{12}',
    'LT' => '(\d{9}|\d{12})',
    'LU' => '\d{8}',
    'LV' => '\d{11}',
    'MK' => '\d{13}',
    'MT' => '\d{8}',
    'NG' => '\d{8}-\d{4}',
    'NL' => '\d{9}B\d{2}',
    'NO' => '\d{9}MVA',
    'NZ' => '\d{9}',
    'PH' => '\d{12}',
    'PL' => '\d{10}',
    'PT' => '\d{9}',
    'RO' => '\d{2,10}',
    'RS' => '\d{9}',
    'RU' => '\d{10}',
    'SA' => '\d{15}',
    'SE' => '\d{12}',
    'SI' => '\d{8}',
    'SK' => '\d{10}',
    'SM' => '\d{5}',
    'TR' => '\d{10}',
    'UA' => '\d{12}',
    'UZ' => '2\d{7}[A-Z]',
];

public static function isValid(string $countryCode, string $identifier): bool
{
    $vatNumber = str_replace(' ', '', strtoupper($vatNumber));
    
    if (!array_key_exists($countryCode, self::COUNTRY_VALIDATION_PATTERNS)) {
        return false;
    }

    return preg_match('/^' . self::COUNTRY_VALIDATION_PATTERNS[$countryCode] . '$/', $identifier) > 0;
}