diff --git a/goodchain/src/classes/User.py b/goodchain/src/classes/User.py
index 9c09827..32ee093 100644
--- a/goodchain/src/classes/User.py
+++ b/goodchain/src/classes/User.py
@@ -35,6 +35,7 @@ class User:
 
         # check if username is already taken
         if self.db.fetchUserByUsername(input_username):
+            print("Username already taken")
             return False
 
         # create sig for user
@@ -73,3 +74,20 @@ class User:
             print('Password updated')
         else:
             print('Something went wrong while trying to update password..')
+
+    def updateAccount(self):
+        # Get new username
+        new_username = input('Enter your new username: ')
+
+        # check if username is already taken
+        if self.db.fetchUserByUsername(new_username):
+            print("Username already taken")
+            return False
+
+        private_key_bytes = Signature.privateKeyToBytes(self.private_key)
+
+        if self.db.changeUsername(private_key_bytes, new_username) == True:
+            print('Username updated')
+        else:
+            print('Something went wrong while trying to update username..')
+
diff --git a/goodchain/src/helpers/DatabaseHelper.py b/goodchain/src/helpers/DatabaseHelper.py
index 2726289..b3885f2 100644
--- a/goodchain/src/helpers/DatabaseHelper.py
+++ b/goodchain/src/helpers/DatabaseHelper.py
@@ -53,7 +53,7 @@ class DatabaseHelper:
 
     def createUser(self, private_key, public_key, username, password):
         if not self.conn:
-            return False
+            return None
         try:
             self.cursor.execute("INSERT INTO `users` (private_key, public_key, username, password) VALUES (?, ?, ?, ?)", (private_key, public_key, username, password,))
             self.commit()
@@ -76,6 +76,37 @@ class DatabaseHelper:
             print(error)
             return None
         
+    def changeUsername(self, user_privatekey, username):
+        if not self.conn:
+            return None
+
+        # Execute the query
+        try:
+            self.cursor.execute("UPDATE `users` SET username = ? WHERE `private_key` = ?", (username, user_privatekey,))
+            self.commit()
+
+            return True
+
+        except sqlite3.Error as error:
+            print(error)
+            return None
+
+    def deleteUser(self, user_privatekey):
+        # Check if the database is open
+        if not self.conn:
+            return None
+
+        # Execute the query
+        try:
+            self.cursor.execute("DELETE FROM `users` WHERE `private_key` = ?", (user_privatekey, ))
+            self.commit()
+
+            return True
+
+        except sqlite3.Error as error:
+            print(error)
+            return None
+        
     def fetchUserByUsername(self, username):
         if not self.conn:
             return None
diff --git a/goodchain/src/helpers/MenuHelper.py b/goodchain/src/helpers/MenuHelper.py
index 62384a4..4cdf2ae 100644
--- a/goodchain/src/helpers/MenuHelper.py
+++ b/goodchain/src/helpers/MenuHelper.py
@@ -164,7 +164,7 @@ class MenuHelper:
                     print(user.private_key)
                 
                 case "Change username":
-                    print("TODO")
+                    user.updateAccount()
 
                 case "Change password":
                     user.updatePassword()