diff --git a/superfaktura/bank_account.py b/superfaktura/bank_account.py
index 32ba57c..748ba85 100644
--- a/superfaktura/bank_account.py
+++ b/superfaktura/bank_account.py
@@ -1,3 +1,36 @@
+"""
+Bank Account Module.
+
+This module provides classes and functions for working with bank accounts in the SuperFaktura API.
+It allows for retrieving, creating, updating, and deleting bank accounts.
+
+Classes:
+    - BankAccountModel: Dataclass representing a bank account.
+    - BankAccount: Class for interacting with bank accounts.
+
+Exceptions:
+    - NoDefaultBankAccountException: Exception for when no default bank account is found.
+
+Functions:
+    - (none)
+
+Usage:
+    import superfaktura.bank_account
+
+    # Create an instance of BankAccount
+    bank = superfaktura.bank_account.BankAccount()
+
+    # Retrieve a list of bank accounts
+    accounts = bank.list()
+
+    # Get the default bank account
+    default_account = bank.default()
+
+    # Create or update a bank account
+    data = {"account": "1234567890", "bank_code": "1234567890", "default": True}
+    bank.post(data)
+"""
+
 from dataclasses import dataclass, asdict
 from typing import Optional
 
@@ -5,11 +38,13 @@ from superfaktura.superfaktura_api import SuperFakturaAPI
 
 
 class NoDefaultBankAccountException(Exception):
-    pass
+    """Exception for when no default bank account is found."""
 
 
 @dataclass
 class BankAccountModel:
+    """Dataclass representing a bank account."""
+
     account: Optional[str]
     bank_code: Optional[str]
     bank_name: Optional[str]
@@ -20,6 +55,7 @@ class BankAccountModel:
     id: Optional[int]
 
     def as_dict(self) -> dict:
+        """Returns a dictionary representation of the BankAccountModel."""
         data = asdict(self)
         for key in list(data.keys()):
             if data[key] is None:
@@ -28,24 +64,42 @@ class BankAccountModel:
 
     @staticmethod
     def from_dict(data: dict) -> "BankAccountModel":
+        """Creates a BankAccountModel from a dictionary."""
         return BankAccountModel(
-            **{
-                k: v
-                for k, v in data.items()
-                if k in BankAccountModel.__dataclass_fields__
-            }
+            **{k: v for k, v in data.items() if k in BankAccountModel.__annotations__}
         )
 
 
 class BankAccount(SuperFakturaAPI):
+    """
+    Bank Account Class.
+
+    This class provides methods for interacting with bank accounts in the SuperFaktura API.
+    It allows for retrieving, creating, updating, and deleting bank accounts.
+
+    Methods:
+        - list: Retrieves a list of bank accounts.
+        - default: Retrieves the default bank account.
+        - post: Creates or updates a bank account.
+
+    Usage:
+        bank = BankAccount()
+        accounts = bank.list()
+        default_account = bank.default()
+        data = {"account": "1234567890", "bank_code": "1234567890", "default": True}
+        bank.post(data)
+    """
+
     def __init__(self):
         super().__init__()
 
     def list(self) -> dict:
+        """Retrieves a list of bank accounts."""
         url = "bank_accounts/index"
         return self.get(url)
 
     def default(self) -> Optional[BankAccountModel]:
+        """Retrieves the default bank account."""
         accounts = self.list()["BankAccounts"]
         for account in accounts:
             if account["BankAccount"]["default"]: