$re = '/^(?:(?:\+|00)33[\s.-]{0,3}(?:\(0\)[\s.-]{0,3})?|0)[1-9](?:(?:[\s.-]?\d{2}){4}|\d{2}(?:[\s.-]?\d{3}){2})$/m';
$str = '~ Accepted ~
0123456789
01 23 45 67 89
01.23.45.67.89
0123 45.67.89
0033 123-456-789
0033(0)123456789
+33-1.23.45.67.89
+33 - 123 456 789
+33(0) 123 456 789
+33 (0)123 45 67 89
+33 (0)1 2345-6789
+33(0) - 123456789
--------------------------------
~ Rejected ~
012345678
01234567890
0+123456789
(0)123456789
01 23 45 67 89
--------------------------------
~ Accepted but strange ~
+33.-.123456789
+33.-.(0)-.-123456789
01 23.45-67.89
';
preg_match_all($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