diff --git a/lib/src/parsers/_national_number_parser.dart b/lib/src/parsers/_national_number_parser.dart
index 461950e..3458bcd 100644
--- a/lib/src/parsers/_national_number_parser.dart
+++ b/lib/src/parsers/_national_number_parser.dart
@@ -73,9 +73,7 @@ abstract class NationalNumberParser {
 
     var transformed = transformRule;
     bool shouldContinueLoop(int i) =>
-        match.groupCount >= i &&
-        match.group(i) != null &&
-        transformed.contains('\$$i');
+        match.groupCount >= i && match.group(i) != null;
     for (var i = 1; shouldContinueLoop(i); i++) {
       transformed = transformed.replaceFirst('\$$i', match.group(i)!);
     }
diff --git a/test/phone_number_test.dart b/test/phone_number_test.dart
index d6296b4..9748f0c 100644
--- a/test/phone_number_test.dart
+++ b/test/phone_number_test.dart
@@ -407,4 +407,50 @@ void main() {
       expect(zero.isSequentialTo(two), isFalse);
     });
   });
+  group(
+      'format national phone number if transformRule does not start with \$1. example: (\$2 15-\$3-\$4)(AR)',
+      () {
+    test('should format argentinian phone numbers', () {
+      String format(String phoneNumber) =>
+          PhoneNumber.parse(phoneNumber, destinationCountry: IsoCode.AR)
+              .formatNsn();
+      var testNumber = '';
+      expect(format(testNumber), equals(''));
+      testNumber = '5';
+      expect(format(testNumber), equals('5'));
+      testNumber = '54';
+      expect(format(testNumber), equals('54'));
+      testNumber = '549';
+      expect(format(testNumber), equals('549'));
+      testNumber = '5492';
+      expect(format(testNumber), equals('5492'));
+      testNumber = '54926';
+      expect(format(testNumber), equals('54926'));
+      testNumber = '549261';
+      expect(format(testNumber), equals('549261'));
+      testNumber = '5492615';
+      expect(format(testNumber), equals('5492615'));
+      testNumber = '54926153';
+      expect(format(testNumber), equals('54926153'));
+      testNumber = '549261532';
+      expect(format(testNumber), equals('549261532'));
+      testNumber = '5492615325';
+      expect(format(testNumber), equals('5492615325'));
+
+      testNumber = '54926153256';
+      expect(format(testNumber), equals('54926153256'));
+      testNumber = '549261532565';
+      expect(format(testNumber), equals('549261532565'));
+      testNumber = '5492615325656';
+      expect(format(testNumber), equals('261 15-532-5656'));
+      testNumber = '+5492615325656';
+      expect(format(testNumber), equals('261 15-532-5656'));
+      testNumber = '54 9 261-5325 656';
+      expect(format(testNumber), equals('261 15-532-5656'));
+      testNumber = '54-9-261-5325-656';
+      expect(format(testNumber), equals('261 15-532-5656'));
+      testNumber = '54.9.261.5325.656';
+      expect(format(testNumber), equals('261 15-532-5656'));
+    });
+  });
 }