$re = '/(?:\d[ -]*?){13,16}\b/';
$str = '9999 - 9999 - 9999 - 9
9999 - 9999 - 9999 - 99
9999 - 9999 - 9999 - 999
9999 - 9999 - 9999 - 9999
999 - 999 - 999 - 999 - 999
99-99-99-99-99-99-99
9-9-9-9-9-9-9-9-9-9-9-9-9
';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php