diff --git a/api.py b/api.py
index 563e040..cec798e 100644
--- a/api.py
+++ b/api.py
@@ -15,6 +15,7 @@ from flask_session import Session # Imports the session module
 #################
 
 def create_app():
+    """Creates the API using Connexion."""
     app = connexion.FlaskApp(__name__)
     app.add_api(CONFIG["api_file"]["name"])
 
@@ -26,6 +27,7 @@ def create_app():
     return app
 
 def API():
+    """Runs the API."""
     app = create_app()
     app.run(host=CONFIG["server"]["listen_ip"], port=CONFIG["server"]["port"], debug=CONFIG["server"]["debug"]) # Runs the API using the configuration file
 
diff --git a/application/account.py b/application/account.py
index 0c10974..e459b93 100644
--- a/application/account.py
+++ b/application/account.py
@@ -1,7 +1,6 @@
 import tkinter as tk
-from tkinter import ttk
+from tkinter import ttk, messagebox
 import customtkinter
-import json
 from config import CONFIG
 from connection import get_transactions, format_balance, get_account
 import sys
@@ -14,23 +13,20 @@ if len(sys.argv) > 3:  # Check if the account description is provided as a comma
     account_id = sys.argv[1]
     account_description = sys.argv[3]
 else:
-    print("Error: Account description not provided.")
+    messagebox.showerror("Error", "Account ID and description were not provided by the server.")
     sys.exit(1)
 
 def populate_transactions_table(transactions_table, account_id):
+    """Populate the transactions table with data for the given account ID."""
     response = get_transactions(account_id)  # Fetch the transactions for the account
-    print(f"Response from get_transactions: {response}")  # Print the response
     if response is None or 'data' not in response:
-        print(f"Error: Unable to fetch transactions for account {account_id}")
+        messagebox.showerror("Error", "Could not fetch transactions for the account.")
         return
     transactions = response['data']
     if not isinstance(transactions, list):
-        print(f"Error: Expected a list of transactions, but got {type(transactions)}")
+        messagebox.showerror("Error", "Data is not formatted as expected.")
         return
-    
-    # Sort transactions by timestamp in descending order
-    transactions.sort(key=lambda x: x['timestamp'], reverse=True)
-    
+    transactions.sort(key=lambda x: x['timestamp'], reverse=True) # Sort transactions by timestamp in descending order
     for transaction in transactions:  # Insert the transactions into the transactions_table
         transactions_table.insert('', 'end', values=(
             transaction['transaction_id'], 
diff --git a/application/app.ini b/application/app.ini
index 30c7758..114f21c 100644
--- a/application/app.ini
+++ b/application/app.ini
@@ -1,14 +1,13 @@
 [server]
-ip=0.0.0.0
-port=81
-url=http://127.0.0.1:81
+ip = 0.0.0.0
+port = 81
+url = http://127.0.0.1:81
 
 [preferences]
-dark_theme=dark
-# Modes: light, dark
-theme=dark-blue
-# Themes: blue, dark-blue, green
+dark_theme = dark
+theme = dark-blue
 
 [client]
-default_id=31d90aad
-default_password=Happymeal1
+default_id = 31d90aad
+default_password = Happymeal1
+
diff --git a/application/connection.py b/application/connection.py
index 1c34d28..d9b5f72 100644
--- a/application/connection.py
+++ b/application/connection.py
@@ -8,9 +8,7 @@ import json
 ##############
 
 def format_balance(balance):
-    """
-    Formats the balance as a currency string with comma separators.
-    """
+    """Formats the balance as a currency string with comma separators."""
     return f"€{balance:,.2f}"
 
 #####################
@@ -18,9 +16,7 @@ def format_balance(balance):
 #####################
 
 def authenticate_client(client_id, client_password):
-    """
-    Authenticates a client with the given client_id and client_password.
-    """
+    """Authenticates a client with the given client_id and client_password."""
     try:
         response = requests.post(CONFIG["server"]["url"] + "/Client/Login", params={'client_id': client_id, 'password': client_password})
         return response
@@ -32,9 +28,7 @@ def authenticate_client(client_id, client_password):
         return response
     
 def logout_client():
-    """
-    Logs out the current client.
-    """
+    """Logs out the current client."""
     try:
         with open('application\\session_data.json', 'r') as f:
             session_data = json.load(f)
@@ -48,9 +42,7 @@ def logout_client():
         return response
 
 def get_client(client_id):
-    """
-    Retrieves the client details for the given client_id.
-    """
+    """Retrieves the client details for the given client_id."""
     try:
         with open('application\\session_data.json', 'r') as f:
             session_data = json.load(f)
@@ -62,9 +54,7 @@ def get_client(client_id):
         return {'success': False, 'message': "Could not connect to the server. Please try again later."}
 
 def update_client(client_id, email=None, phone_number=None, address=None):
-    """
-    Updates the client details for the given client_id.
-    """
+    """Updates the client details for the given client_id."""
     try:
         with open('application\\session_data.json', 'r') as f:
             session_data = json.load(f)
@@ -83,9 +73,7 @@ def update_client(client_id, email=None, phone_number=None, address=None):
         return {'success': False, 'message': "Could not connect to the server. Please try again later."}
 
 def get_accounts(client_id):
-    """
-    Retrieves the accounts associated with the given client_id.
-    """
+    """Retrieves the accounts associated with the given client_id."""
     try:
         with open('application\\session_data.json', 'r') as f:
             session_data = json.load(f)
@@ -100,9 +88,7 @@ def get_accounts(client_id):
         return {'success': False, 'message': "Could not connect to the server. Please try again later."}
 
 def get_transactions(account_id):
-    """
-    Retrieves the transactions for the given account_id.
-    """
+    """Retrieves the transactions for the given account_id."""
     try:
         with open('application\\session_data.json', 'r') as f:
             session_data = json.load(f)
@@ -117,9 +103,7 @@ def get_transactions(account_id):
         return {'success': False, 'message': "Could not connect to the server. Please try again later."}
 
 def get_account(account_id):
-    """
-    Retrieves the account details for the given account_id.
-    """
+    """Retrieves the account details for the given account_id."""
     try:
         with open('application\\session_data.json', 'r') as f:
             session_data = json.load(f)
@@ -135,9 +119,7 @@ def get_account(account_id):
         return {'success': False, 'message': "Could not connect to the server. Please try again later."}
 
 def update_account(account_id, description=None, notes=None):
-    """
-    Updates the account details for the given account_id.
-    """
+    """Updates the account details for the given account_id."""
     try:
         with open('application\\session_data.json', 'r') as f:
             session_data = json.load(f)
@@ -154,9 +136,7 @@ def update_account(account_id, description=None, notes=None):
         return {'success': False, 'message': "Could not connect to the server. Please try again later."}
 
 def new_transaction(account):
-    """
-    Creates a new transaction for the given account.
-    """
+    """Creates a new transaction for the given account."""
     try:
         with open('application\\session_data.json', 'r') as f:
             session_data = json.load(f)
diff --git a/application/dashboard.py b/application/dashboard.py
index f97f376..01bd90a 100644
--- a/application/dashboard.py
+++ b/application/dashboard.py
@@ -15,13 +15,18 @@ frame = None
 ### Functions ###
 #################
 
+def go_to_login():
+    """Closes the current window and opens the login page."""
+    root.destroy()
+    login_page()  # Replace with your function or class that opens the login page
+
 def logout():
-    """Logs out the client and closes the application."""
+    """Logs out the client and redirects to the login page."""
     response = logout_client()
     json_response = response.json()
     if json_response['success']:
         messagebox.showinfo("Logout", "You have been logged out.")
-        root.destroy()
+        go_to_login()
     else:
         messagebox.showerror("Logout failed", json_response['message'])
 
diff --git a/application/login.py b/application/login.py
index dfb07a0..a9ad6db 100644
--- a/application/login.py
+++ b/application/login.py
@@ -6,13 +6,15 @@ import json
 import requests
 from connection import authenticate_client
 from config import CONFIG
+import configparser, sys
+
 
 #################
 ### Functions ###
 #################
 
 def login():
-    """Function to handle the login process."""
+    """Authenticate the client and open the dashboard if successful."""
     client_id = entry_username.get() if entry_username.get() else CONFIG["client"]["default_id"]
     client_password = entry_password.get() if entry_password.get() else CONFIG["client"]["default_password"]
     try:
@@ -32,6 +34,20 @@ def login():
     except requests.exceptions.RequestException as e:
         messagebox.showerror("Login failed", f"Could not connect to the server. Please try again later. Error: {str(e)}")
 
+def change_dark_theme():
+    """Change the theme between dark and light."""
+    config = configparser.ConfigParser()
+    config.read('application/app.ini')
+    if 'preferences' in config:
+        current_theme = config.get('preferences', 'dark_theme')
+        new_theme = 'light' if current_theme == 'dark' else 'dark'
+        config.set('preferences', 'dark_theme', new_theme)
+        with open('application/app.ini', 'w') as configfile:
+            config.write(configfile)
+        os.execl(sys.executable, sys.executable, *sys.argv)
+    else:
+        messagebox.showerror("Error", "Could not change the theme. Please check the configuration file.")
+
 ##############
 ### Layout ###
 ##############
@@ -64,6 +80,10 @@ entry_password.pack(pady=10)
 login_button = customtkinter.CTkButton(root, text="Login", command=login)
 login_button.pack(pady=15)
 
+# Create and pack the theme change button
+theme_button = customtkinter.CTkButton(root, text="Change Theme", command=change_dark_theme)
+theme_button.pack(side='bottom', anchor='w')
+
 # Bind the Return key to the login function
 root.bind('<Return>', lambda event=None: login())
 
diff --git a/application/session_data.json b/application/session_data.json
index 974efb2..a72e368 100644
--- a/application/session_data.json
+++ b/application/session_data.json
@@ -1 +1 @@
-{"session_cookie": {"session": "snGl2pPHJKUmCdGIH4QdeIgGmzaPxjFZsUe30lxaMpk"}, "client_id": "31d90aad"}
\ No newline at end of file
+{"session_cookie": {"session": "G1SQpUTHsed2pPeVe4-1vtqwOXzE5-HMGZKWxvNqzTs"}, "client_id": "31d90aad"}
\ No newline at end of file
diff --git a/class_account.py b/class_account.py
index 7e64ba2..ca84dd8 100644
--- a/class_account.py
+++ b/class_account.py
@@ -19,6 +19,7 @@ class Account(Base):
     transactions = relationship("Transaction", foreign_keys='Transaction.account_id', backref="account")
                     
     def __init__(self, account_id, client_id, description, open_timestamp, account_type, balance, enabled, notes, transactions):
+        """Initialises the account object."""
         self.account_id = account_id
         self.client_id = client_id
         self.description = description
@@ -30,6 +31,7 @@ class Account(Base):
         self.transactions = transactions if transactions is not None else []
     
     def to_dict(self):
+        """Returns the account as a dictionary."""
         return {
             "account_id": self.account_id,
             "client_id": self.client_id,
diff --git a/class_client.py b/class_client.py
index 09cca30..8c7da78 100644
--- a/class_client.py
+++ b/class_client.py
@@ -22,6 +22,7 @@ class Client(Base):
     accounts = relationship("Account", backref="client")
 
     def __init__(self, client_id, name, birthdate, opening_timestamp, address, phone_number, email, hash, notes, enabled, administrator, accounts):
+        """Initialises the client object."""
         self.client_id = client_id
         self.name = name
         self.birthdate = birthdate
@@ -36,6 +37,7 @@ class Client(Base):
         self.accounts = accounts if accounts is not None else []
     
     def to_dict(self):
+        """Returns the client as a dictionary."""
         return {
             "client_id": self.client_id,
             "name": self.name,
diff --git a/class_transaction.py b/class_transaction.py
index ddc2158..eddc3fa 100644
--- a/class_transaction.py
+++ b/class_transaction.py
@@ -16,6 +16,7 @@ class Transaction(Base):
     recipient_account_id = Column(String, ForeignKey('accounts.account_id'))
 
     def __init__(self, transaction_id, transaction_type, amount, timestamp, description, account_id, recipient_account_id = None):
+        """Initialises the Transaction object."""
         self.transaction_id = transaction_id
         self.transaction_type = transaction_type
         self.amount = amount
@@ -25,6 +26,7 @@ class Transaction(Base):
         self.recipient_account_id = recipient_account_id
 
     def to_dict(self):
+        """Converts the Transaction object to a dictionary."""
         return {
             "transaction_id": self.transaction_id,
             "transaction_type": self.transaction_type,
diff --git a/emailer.py b/emailer.py
index 4d95ab5..64adc85 100644
--- a/emailer.py
+++ b/emailer.py
@@ -13,6 +13,7 @@ subject = "Test Email"
 body = "This is a test email."
 
 def send_email(receiver_email, subject, body):
+    """Sends an email to the specified receiver email address."""
     sender_email = CONFIG["smtp"]["sender_email"]
 
     message = MIMEMultipart() # Create a multipart message and set headers
diff --git a/manager.py b/manager.py
index 73ad0d9..08f7429 100644
--- a/manager.py
+++ b/manager.py
@@ -22,25 +22,31 @@ otps = {} # Temporary dictionary to store OTPs and their creation time
 ### System ###
 ##############
 
-def timestamp(): # Returns the current timestamp
+def timestamp():
+    """Returns the current timestamp in the format 'YYYY-MM-DD HH:MM:SS'."""
     return (datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S"))
 
-def hash_password(password:str): # Converts a string to SHA512 hash
+def hash_password(password:str):
+    """Hashes a password using the SHA-512 algorithm and returns the hexadecimal representation of the hash."""
     return hashlib.sha512(password.encode()).hexdigest()
 
-def generate_uuid(): # Generates a unique identifier for transactions
+def generate_uuid():
+    """Generates a unique identifier using the UUID4 algorithm and returns it as a string."""
     return str(uuid.uuid4())
 
-def generate_uuid_short(): # Generates a short uuid
+def generate_uuid_short():
+    """Generates a short unique identifier using the UUID4 algorithm and returns the first 8 characters as a string."""
     return str(uuid.uuid4())[:8]
 
-def get_email(client_id:str): # Returns the email of a client
+def get_email(client_id:str):
+    """Returns the email of a client given their client_id. If the client is not found, returns None."""
     for client in session.query(Client).all():
         if client.client_id == client_id:
             return client.email
     return None
 
-def format_response(success: bool, message: str = '', data: dict = None): # Formats the response for the API so that it is standardised across all functions
+def format_response(success: bool, message: str = '', data: dict = None):
+    """Formats the response for the API so that it is standardised across all functions."""
     response = {
         'success': success,
         'message': message,
@@ -50,22 +56,28 @@ def format_response(success: bool, message: str = '', data: dict = None): # Form
     return jsonify(response)
 
 def get_current_client():
+    """Returns the client_id and administrator status of the currently logged in client. If no client is logged in, returns None, None."""
+    if 'client_id' not in flask_session:
+        return None, None
     client = flask_session['client_id']
     client_obj = session.query(Client).filter_by(client_id=client).one_or_none()
     if client_obj is None:
         return None, None
     return client_obj.client_id, client_obj.administrator
 
-def verify_otp(client_id:str, otp:int): # Verifies a one time password for a client
+def verify_otp(client_id:str, otp:int):
+    """Verifies a one time password for a client. Returns True if the OTP is correct and False otherwise."""
     if client_id in otps and otps[client_id][0] == otp:
         return True
     return False
 
-def delete_otp(client_id:str): # Deletes a one time password for a client
+def delete_otp(client_id:str):
+    """Deletes the OTP for a client."""
     if client_id in otps:
         del otps[client_id]
 
-def check_expired_otps(): # Checks and deletes expired OTPs
+def check_expired_otps():
+    """Checks for expired OTPs and deletes them. An OTP is considered expired if it is older than 5 minutes."""
     current_time = time.time()
     expired_otps = [client_id for client_id, (otp, creation_time) in otps.items() if current_time - creation_time > 300]  # Find OTPs older than 5 minutes
     for client_id in expired_otps:
@@ -75,7 +87,8 @@ def check_expired_otps(): # Checks and deletes expired OTPs
 ### Authentication ###
 ######################
 
-def login(client_id:str, password:str): # Logs in a user
+def login(client_id:str, password:str):
+    """Logs in a client using their client_id and password. Returns a success message if the login is successful and an error message otherwise."""
     password_hash = hash_password(password)
     for client in session.query(Client).all():
         if client.client_id == client_id and client.hash == password_hash:
@@ -84,18 +97,21 @@ def login(client_id:str, password:str): # Logs in a user
     return format_response(False, "Invalid client_id or password."), 400
         
 def logout():
+    """Logs out a client. Returns a success message if the logout is successful and an error message otherwise."""
     if 'client_id' in flask_session:
         flask_session.pop('client_id', None)
         return format_response(True, "Logged out successfully."), 200
     return format_response(False, "Not logged in."), 400
 
 def status():
+    """Returns the current status of the client."""
     if 'client_id' in flask_session:
         return format_response(True, f"Logged in as {flask_session['client_id']}"), 200
     else:
         return format_response(False, "Not logged in."), 400
     
 def login_required(f):
+    """Decorator function to check if a client is logged in before accessing a route."""
     @wraps(f)
     def decorated_function(*args, **kwargs):
         if 'client_id' not in flask_session:
@@ -104,6 +120,7 @@ def login_required(f):
     return decorated_function
 
 def admin_required(f):
+    """Decorator function to check if a client is an administrator before accessing a route."""
     @wraps(f)
     def decorated_function(*args, **kwargs):
         if 'client_id' not in flask_session:
@@ -116,7 +133,8 @@ def admin_required(f):
     return decorated_function
 
 @login_required
-def generate_otp(client_id:str): # Generates a one time password for a client
+def generate_otp(client_id:str):
+    """Generates a one time password for a client and sends it to their email address. Returns a success message if the OTP is generated and an error message otherwise."""
     current_client_id, is_admin = get_current_client()
     if not is_admin and client_id != current_client_id:
         return format_response(False, "You can only generate OTPs for your own client account."), 403   
@@ -133,7 +151,8 @@ def generate_otp(client_id:str): # Generates a one time password for a client
 ##############
 
 @login_required
-def get_client(client_id:str): # Returns a specific client in the database
+def get_client(client_id:str):
+    """Returns a specific client in the database. If the client is not found, returns an error message."""
     current_client_id, is_admin = get_current_client()
     if not is_admin and client_id != current_client_id:
         return format_response(False, "You can only view your own client information."), 403
@@ -143,7 +162,8 @@ def get_client(client_id:str): # Returns a specific client in the database
     return format_response(False, "Client not found."), 404
 
 @login_required
-def update_client(client_id:str, **kwargs): # Updates a client in the database
+def update_client(client_id:str, **kwargs):
+    """Updates a client in the database. If the client is not found, returns an error message."""
     current_client_id, is_admin = get_current_client()
     if not is_admin and client_id != current_client_id:
         return format_response(False, "You can only view your own client information."), 403
@@ -172,7 +192,8 @@ def update_client(client_id:str, **kwargs): # Updates a client in the database
     return format_response(False, "Client not found."), 404
 
 @login_required
-def change_password(client_id:str, password:str, new_password:str, otp:int): # Changes the password of a client
+def change_password(client_id:str, password:str, new_password:str, otp:int):
+    """Changes the password for a client in the database. If the client is not found, returns an error message."""
     current_client_id, is_admin = get_current_client()
     if not is_admin and client_id != current_client_id:
         return format_response(False, "You can only update your own client information."), 403
@@ -192,9 +213,9 @@ def change_password(client_id:str, password:str, new_password:str, otp:int): # C
 
 @login_required
 def get_accounts(client_id: str):
+    """Returns all accounts for a specific client in the database. If the client is not found, returns an error message."""
     current_client_id, is_admin = get_current_client()
     if current_client_id is None:
-        # return an appropriate response or raise an exception
         raise Exception("No current client found")
     if not is_admin and client_id != current_client_id:
         return format_response(False, "You can only view your own client information."), 403
@@ -206,7 +227,7 @@ def get_accounts(client_id: str):
 ###############
 
 @login_required
-def get_account(account_id:str): # Returns a specific account in the database
+def get_account(account_id:str):
     current_client_id, is_admin = get_current_client()
     account_owner = session.query(Account).filter_by(account_id=account_id).one_or_none().client_id
     if not is_admin and account_owner != current_client_id:
@@ -218,7 +239,8 @@ def get_account(account_id:str): # Returns a specific account in the database
     return format_response(False, "Account not found."), 404
 
 @login_required
-def add_account(client_id:str, description:str, account_type:str, **kwargs): # Adds a new account to the database
+def add_account(client_id:str, description:str, account_type:str, **kwargs):
+    """Adds a new account to the database. If the client is not found, returns an error message."""
     current_client_id, is_admin = get_current_client()
     if not is_admin and client_id != current_client_id:
         return format_response(False, "You can only view your own client information."), 403
@@ -237,7 +259,8 @@ def add_account(client_id:str, description:str, account_type:str, **kwargs): # A
     return format_response(True, f"New account has been added: account_id: {account_id}"), 200
 
 @login_required       
-def update_account(account_id:str, **kwargs): # Updates an account in the database    
+def update_account(account_id:str, **kwargs):
+    """Updates an account in the database. If the account is not found, returns an error message."""
     current_client_id, is_admin = get_current_client()
     account_owner = session.query(Account).filter_by(account_id=account_id).one_or_none().client_id
     if not is_admin and account_owner != current_client_id:
@@ -268,7 +291,8 @@ def update_account(account_id:str, **kwargs): # Updates an account in the databa
 ###################
 
 @login_required
-def get_transaction(transaction_id:int): # Returns a specific transaction in the database
+def get_transaction(transaction_id:int):
+    """Returns a specific transaction in the database. If the transaction is not found, returns an error message."""
     current_client_id, is_admin = get_current_client()
     transaction = session.query(Transaction).filter_by(transaction_id=transaction_id).one_or_none()
     if not transaction:
@@ -280,7 +304,8 @@ def get_transaction(transaction_id:int): # Returns a specific transaction in the
     return format_response(True, "", transaction.to_dict()), 200
 
 @login_required
-def add_transaction(amount:int, account_id, recipient_account_id, **kwargs): # Adds a new transaction to the database
+def add_transaction(amount:int, account_id, recipient_account_id, **kwargs):
+    """Adds a new transaction to the database. If the account is not found, returns an error message."""
     current_client_id, is_admin = get_current_client()
     if not is_admin and account_id != current_client_id:
         return format_response(False, "You can only view your own client information."), 403
@@ -290,23 +315,21 @@ def add_transaction(amount:int, account_id, recipient_account_id, **kwargs): # A
             account_from = account
         if account.account_id == recipient_account_id:
             account_dest = account
-    # Check if account has enough funds
-    if account_from.balance < amount:
+    if account_from.balance < amount: # Check if account has enough funds
         return format_response(False, "Insufficient funds."), 400
-    # Perform the transaction
-    account_from.balance -= amount
+    account_from.balance -= amount # Perform the transaction
     account_dest.balance += amount
     transaction_type = "transfer"
     session.commit()
-    # Create the transaction record
-    description = kwargs.get("description", None)
+    description = kwargs.get("description", None) # Create the transaction record
     new_transaction = Transaction(transaction_id, transaction_type, amount, timestamp(), description, account_id, recipient_account_id)
     session.add(new_transaction)
     session.commit()
     return format_response(True, f"New transaction has been added: transaction_id: {transaction_id}"), 200 
 
 @login_required
-def transaction_history(account_id:int): # Returns all transactions for a specific account
+def transaction_history(account_id:int):
+    """Returns all transactions for a specific account in the database. If the account is not found, returns an error message."""
     current_client_id, is_admin = get_current_client()
     account = session.query(Account).filter_by(account_id=account_id).one_or_none()
     if not account:
@@ -321,10 +344,10 @@ def transaction_history(account_id:int): # Returns all transactions for a specif
 #####################
 
 @admin_required
-def delete_client(client_id:str): # Deletes a client from the database
+def delete_client(client_id:str):
+    """Deletes a client from the database. If the client is not found, returns an error message."""
     if client_id == flask_session['client_id']:
         return format_response(False, "You cannot delete your own account."), 400
-    
     for client in session.query(Client).all():
         if client.client_id == client_id:
             if client.accounts == None:
@@ -336,7 +359,8 @@ def delete_client(client_id:str): # Deletes a client from the database
     return format_response(False, "Client not found."), 404
 
 @admin_required
-def delete_account(account_id:str): # Deletes an account from the database
+def delete_account(account_id:str):
+    """Deletes an account from the database. If the account is not found, returns an error message."""
     for account in session.query(Account).all():
         if account.account_id == account_id:
             if account.balance == 0:
@@ -348,22 +372,26 @@ def delete_account(account_id:str): # Deletes an account from the database
     return format_response(False, "Account not found."), 404
 
 @admin_required
-def get_all_clients(): # Returns all clients in the database
+def get_all_clients():
+    """Returns all clients in the database."""
     clients = session.query(Client).all()
     return format_response(True, "", [client.to_dict() for client in clients]), 200
 
 @admin_required
-def get_all_accounts(): # Returns all accounts in the database
+def get_all_accounts():
+    """Returns all accounts in the database."""
     accounts = session.query(Account).all()
     return format_response(True, "", [account.to_dict() for account in accounts]), 200
 
 @admin_required
-def get_all_transactions(): # Returns all transactions in the database
+def get_all_transactions():
+    """Returns all transactions in the database."""
     transactions = session.query(Transaction).all()
     return format_response(True, "", [transaction.to_dict() for transaction in transactions]), 200
 
 @admin_required
 def apply_interest(account_id:int, interest_rate:float):
+    """Applies interest to an account based on the interest rate. If the account is not found, returns an error message."""
     for account in session.query(Account).filter(Account.account_id == account_id):
         if account.account_id == account_id:
             interest = account.balance * interest_rate
@@ -374,6 +402,7 @@ def apply_interest(account_id:int, interest_rate:float):
 
 @admin_required
 def apply_fee(account_id:int, fee:float):
+    """Applies a fee to an account based on the fee amount. If the account is not found, returns an error message."""
     for account in session.query(Account).all():
         if account.account_id == account_id:
             account.balance -= fee
@@ -383,6 +412,7 @@ def apply_fee(account_id:int, fee:float):
 
 @admin_required
 def delete_transaction(transaction_id:int):
+    """Deletes a transaction from the database. If the transaction is not found, returns an error message."""
     for transaction in session.query(Transaction).all():
         if transaction.transaction_id == transaction_id:
             session.delete(transaction)
@@ -392,6 +422,7 @@ def delete_transaction(transaction_id:int):
 
 @admin_required
 def modify_balance(transaction_id:int, amount:int):
+    """Modifies the amount of a transaction in the database. If the transaction is not found, returns an error message."""
     for transaction in session.query(Transaction).all():
         if transaction.transaction_id == transaction_id:
             transaction.amount = amount
@@ -401,6 +432,7 @@ def modify_balance(transaction_id:int, amount:int):
 
 @admin_required
 def test_account_balances():
+    """Checks all account balances in the database and returns a list of discrepancies."""
     all_transactions = session.query(Transaction).all()# Get all transactions from the database
     calculated_balances = {} # Initialize a dictionary to store the calculated balance for each account
     for transaction in all_transactions: # Go through each transaction
@@ -418,7 +450,8 @@ def test_account_balances():
     return format_response(True, "", discrepancies), 200 # Return the list of discrepancies
 
 @admin_required
-def add_client(name:str, birthdate:str, address:str, phone_number:str, email:str, password:str, **kwargs): # Adds a new client to the database
+def add_client(name:str, birthdate:str, address:str, phone_number:str, email:str, password:str, **kwargs):
+    """Adds a new client to the database."""
     client_id = generate_uuid_short()
     notes = kwargs.get("notes", None)
     new_client = Client(client_id, name, birthdate, timestamp(), address, phone_number, email, hash_password(password), notes, 1, 0, None)
@@ -427,6 +460,7 @@ def add_client(name:str, birthdate:str, address:str, phone_number:str, email:str
     return format_response(True, f"New client has been added: client_id: {client_id}"), 200
 
 def initialise_database(password:str, email:str):
+    """Initialises the database with an administrator client if no clients exist."""
     existing_clients = session.query(Client).all() # Check if any clients exist in the database
     if not existing_clients: # If no clients exist, create an administrator client
         add_client('ADMINISTRATOR', 'ADMINISTRATOR', 'ADMINISTRATOR', 'ADMINISTRATOR', email, password)  # Add the administrator client
@@ -439,6 +473,7 @@ def initialise_database(password:str, email:str):
 
 @admin_required
 def promote_to_admin(client_id:str):
+    """Promotes a client to administrator status. If the client is not found, returns an error message."""
     for client in session.query(Client).all():
         if client.client_id == client_id:
             client.administrator = 1
@@ -448,6 +483,7 @@ def promote_to_admin(client_id:str):
 
 @admin_required
 def demote_from_admin(client_id:str):
+    """Demotes a client from administrator status. If the client is not found, returns an error message."""
     for client in session.query(Client).all():
         if client.client_id == client_id:
             client.administrator = 0