$re = '/^(?=(?:[^\n\d]*\d){5})(?!(?:[^\n\d]*\d){21})(?:\(\+\d+\)|\+\d+) ?\d+(?:-\d+)*$/m';
$str = '(+355)250235
+91 123456789012
(+355) 250-236-236-789
(+355) 2502-3656-1236-8789
+920123456789012345987
(+355)2
+91
(+355) 2
+920123456789012345987';
preg_match_all($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