$re = '/\+[\d]{11,14}/i';
$str = 'Иванов Иван иванович !@#$%^&*(_+1234567890-=[]?/
IVANOV Ivan ivanovich !@#$$^&*(_+1234567890-=~`:"{};\'[]|\\<>?,./
IVANOV Ivan !@#$$^&*(_+1234567890-=~`:"{};\'[]|\\<>?,./
+9991234567
+19991234567
+129991234567
+1239991234567
+12349991234567
+1 999 1234567
+1234 (999) 123-45-67
';
$subst = "";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
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