diff --git a/src/main/java/hs/fulda/de/ci/exam/project/BankTransaction.java b/src/main/java/hs/fulda/de/ci/exam/project/BankTransaction.java
index f8b1c2d..26be339 100644
--- a/src/main/java/hs/fulda/de/ci/exam/project/BankTransaction.java
+++ b/src/main/java/hs/fulda/de/ci/exam/project/BankTransaction.java
@@ -25,4 +25,12 @@ public class BankTransaction extends Payment {
     public void setIban(String iban) {
         this.iban = iban;
     }
+
+    @Override
+    public boolean isValid() {
+        if (this.iban.length() != 22) {
+            return false;
+        }
+        return true;
+    }
 }
diff --git a/src/main/java/hs/fulda/de/ci/exam/project/CreditCardTransaction.java b/src/main/java/hs/fulda/de/ci/exam/project/CreditCardTransaction.java
index c2ac2da..742bda6 100644
--- a/src/main/java/hs/fulda/de/ci/exam/project/CreditCardTransaction.java
+++ b/src/main/java/hs/fulda/de/ci/exam/project/CreditCardTransaction.java
@@ -1,10 +1,24 @@
 package hs.fulda.de.ci.exam.project;
 
 public class CreditCardTransaction extends Payment {
-    String nameOnCard;
+    String cardNumber;
 
-    public CreditCardTransaction(int id, String amount, PaymentStatus status, String nameOnCard) {
+    public CreditCardTransaction(int id, String amount, PaymentStatus status, String cardNumber) {
         super(id, amount, status);
-        this.nameOnCard = nameOnCard;
+        this.cardNumber = cardNumber;
+    }
+
+    public String getCardNumber() {
+        return cardNumber;
+    }
+
+    public void setCardNumber(String cardNumber) {
+        this.cardNumber = cardNumber;
+    }
+
+    @Override
+    public boolean isValid() {
+        if (this.cardNumber.length() != 20) return false;
+        return true;
     }
 }
diff --git a/src/main/java/hs/fulda/de/ci/exam/project/FlightReservation.java b/src/main/java/hs/fulda/de/ci/exam/project/FlightReservation.java
index 55c0bb8..2ccfa34 100644
--- a/src/main/java/hs/fulda/de/ci/exam/project/FlightReservation.java
+++ b/src/main/java/hs/fulda/de/ci/exam/project/FlightReservation.java
@@ -3,6 +3,8 @@ package hs.fulda.de.ci.exam.project;
 import java.util.HashMap;
 
 import static hs.fulda.de.ci.exam.project.PaymentStatus.Completed;
+import static hs.fulda.de.ci.exam.project.PaymentStatus.Failed;
+import static hs.fulda.de.ci.exam.project.ReservationStatus.Cancelled;
 import static hs.fulda.de.ci.exam.project.ReservationStatus.Confirmed;
 
 public class FlightReservation {
@@ -55,10 +57,17 @@ public class FlightReservation {
         this.status = status;
     }
 
-    public void makePayment(Payment credit_card_payment) {
+    public void makePayment(Payment payment) {
         System.out.println("processing payment");
-        credit_card_payment.status = Completed;
-        status = Confirmed;
+        if (payment.isValid()) {
+            payment.status = Completed;
+            setStatus(Confirmed);
+        } else {
+            payment.status = Failed;
+            setStatus(Cancelled);
+        }
+
+
     }
 
     public boolean notifyUser(String type, String to, String content) {
diff --git a/src/main/java/hs/fulda/de/ci/exam/project/Payment.java b/src/main/java/hs/fulda/de/ci/exam/project/Payment.java
index f5bc310..21ece7c 100644
--- a/src/main/java/hs/fulda/de/ci/exam/project/Payment.java
+++ b/src/main/java/hs/fulda/de/ci/exam/project/Payment.java
@@ -1,6 +1,6 @@
 package hs.fulda.de.ci.exam.project;
 
-public class Payment {
+public abstract class Payment {
     int id;
     String amount;
     PaymentStatus status;
@@ -34,4 +34,6 @@ public class Payment {
     public void setStatus(PaymentStatus status) {
         this.status = status;
     }
+
+    public abstract boolean isValid();
 }
diff --git a/src/test/java/hs/fulda/de/ci/exam/project/PaymentTest.java b/src/test/java/hs/fulda/de/ci/exam/project/PaymentTest.java
index 62e9961..4a8e535 100644
--- a/src/test/java/hs/fulda/de/ci/exam/project/PaymentTest.java
+++ b/src/test/java/hs/fulda/de/ci/exam/project/PaymentTest.java
@@ -9,7 +9,7 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
 public class PaymentTest {
     @Test
     public void should_be_possible_to_pay_with_credit_card(){
-        Payment credit_card_payment = new CreditCardTransaction(11, "139€", Unpaid, "Imron Gamidli");
+        Payment credit_card_payment = new CreditCardTransaction(11, "139€", Unpaid, "01234567890123456789");
         FlightReservation reservation = new FlightReservation();
         reservation.makePayment(credit_card_payment);
         assertEquals(Confirmed, reservation.getStatus());
@@ -25,5 +25,14 @@ public class PaymentTest {
         assertEquals(Completed, payment.status);
     }
 
+    @Test
+    public void paymentShould_not_be_possible_if_credit_card_deatils_is_wrong(){
+        CreditCardTransaction credit_card_payment = new CreditCardTransaction(11, "139€", Unpaid, "123");
+        FlightReservation reservation = new FlightReservation();
+        reservation.makePayment(credit_card_payment);
+        assertEquals(ReservationStatus.Cancelled, reservation.getStatus());
+        assertEquals(Failed, credit_card_payment.status);
+    }
+
 
 }