$re = '/^ # begin
\s*# some empty spaces
(?:
\+? # + symbol
\d{1,2} # country code
\s*
(?(?=\)) # if followed by parens
| # then dash not allowed
-? # else optional dash
)
)? #prefix like +380
\s*
(?:
(?P<leftparen>\()? # optional left paren
\s*
0\d\d
\s*
(?(leftparen)\)|) # right paren if and only if left paren
)? # operator code, starting with 0, optinally in parentheses
(?(?<=\)) # if preceded by parens
\s*| # then dash not allowed
\s*-?\s* # else optional dash
)
(?:
\d |
(?<=
\d
)
(?(sep)
(?P=sep)|
(?P<sep>[\-\/\ ])
)
(?=
\d
)
){5,13}
\s*# some empty spaces
$ # end
#\d\d\d (?P<separator>-?) \d\d (?P=separator) \d\d $/mx';
$str = 'SHOULD MATCH:
5344654
5344654
534-46-54
17189280121
+19173010176
(095)789-58-75
(095) 789-58-75
0957895875
917 229 2897
+38 (095) 5344654
53-475-34
555-1-333
1-333-484
888-333-4
(094)999-22-44
38-095-432-43-34
095-432-43-34
123456
53465
SHOULD NOT MATCH:
1
-1234
38-(095)-432-43-34
534-46/54
(094)999/22-44
1234--567
(345)5345654
(0955344654
095)5345654
';
preg_match_all($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