$re = '/^(?:(?![,0-9]{14})\d{1,3}(?:,\d{3})*(?:\.\d{1,2})?|(?![.0-9]{14})\d{1,3}(?:\.\d{3})*(?:\,\d{1,2})?)$/m';
$str = '123,456.00
123.456,00
123,456,789.00
123.456.789,00
123.456.789,0
123,456,781,123.00
123.456.789.123,00
234,567,890.89
1,234,567,890.89
1,234,567,890
1,234,567,890.89';
preg_match_all($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