diff --git a/src/main/java/de/hs_mannheim/domain/System.java b/src/main/java/de/hs_mannheim/domain/System.java
index 3494cd1..02f4dd0 100644
--- a/src/main/java/de/hs_mannheim/domain/System.java
+++ b/src/main/java/de/hs_mannheim/domain/System.java
@@ -212,6 +212,30 @@ public class System {
 
     }
     
+    public boolean change_user_password(String old_password, String new_password, String new_password_authentication){
+        if(!this.current_user.getPassword().equals(old_password))
+            return false;
+        
+        if(!new_password.equals(new_password_authentication))
+            return false;    
+        
+        for(int i = 0; i< this.all_user.size(); i++)
+            if(this.all_user.get(i).getUsername().equals(current_user.getUsername()))
+                this.all_user.remove(i);
+        
+        write_to_file(all_user_toString(), "src/main/resources/user_data.csv");
+        write_to_file(all_user_toString(), "src/test/resources/user_data.csv");
+        
+        this.current_user.setPassword(new_password);
+        this.all_user.add(current_user);
+
+        write_to_file(all_user_toString(), "src/main/resources/user_data.csv");
+        write_to_file(all_user_toString(), "src/test/resources/user_data.csv");
+        
+        return true;
+
+    }
+    
     public void write_to_file(ArrayList<String> lines, String file) {
         try (BufferedWriter writer = new BufferedWriter(new FileWriter(file))) {
             for (int i = 0; i < lines.size() - 1; i++) {
diff --git a/src/main/java/de/hs_mannheim/facade/Application.java b/src/main/java/de/hs_mannheim/facade/Application.java
index f93622d..015597b 100644
--- a/src/main/java/de/hs_mannheim/facade/Application.java
+++ b/src/main/java/de/hs_mannheim/facade/Application.java
@@ -30,6 +30,10 @@ public class Application {
         return running_system.change_user_details(username, password, hometown, zip, car_name, car_co2_km, car_avg_kmh, bike_avg_kmh);
     }
 
+    public boolean change_user_password(String old_password, String new_password, String new_password_authentication){
+        return running_system.change_user_password(old_password, new_password, new_password_authentication);
+    }
+
     public ArrayList<String> search(String hometown_or_zip){
         return running_system.search(hometown_or_zip);
     }
diff --git a/src/test/java/de/hs_mannheim/domain/SystemTest.java b/src/test/java/de/hs_mannheim/domain/SystemTest.java
index 8a47749..24344b0 100644
--- a/src/test/java/de/hs_mannheim/domain/SystemTest.java
+++ b/src/test/java/de/hs_mannheim/domain/SystemTest.java
@@ -139,11 +139,24 @@ public class SystemTest {
     public void change_user_details(){
         
         current_system.sign_in_user("David", "123Esel");
-        current_system.change_user_details("Enes", "Penis123", "Mannheim", "68161", "", "", "", "");
+        current_system.change_user_details("Enes", "123Esel", "Mannheim", "68161", "", "", "", "");
         assertEquals("Enes", current_system.getDetails()[0]);
         current_system.change_user_details("David", "123Esel", "Mannheim", "68161", "AMG", "10", "100", "20");
     
     }
+
+    @Test
+    public void change_user_password(){
+
+        current_system.sign_in_user("David", "123Esel");
+        assertEquals(true, current_system.change_user_password("123Esel", "Pizza69", "Pizza69"));
+        assertEquals(true, current_system.change_user_password("Pizza69", "123Esel", "123Esel"));
+        assertEquals(true, current_system.change_user_details("Enes", "123Esel", "Mannheim", "68161", "", "", "", ""));
+        current_system.change_user_details("David", "123Esel", "Mannheim", "68161", "AMG", "10", "100", "20");
+
+        ;
+
+    }
 /*
 Tests auf Basis von user_data.csv:  
 Daniel;MTQwMURhbmllbA==;Mannheim;68305;BMW;1.5;50.4;40.2