diff --git a/banking_breakdown/ui.py b/banking_breakdown/ui.py
index 71c7c4c..8d4499f 100644
--- a/banking_breakdown/ui.py
+++ b/banking_breakdown/ui.py
@@ -130,11 +130,21 @@ class MainWindow(QMainWindow):
                 self._table_view.setColumnWidth(i, max_char * 10)
 
         self._show_warnings(df)
+        self._update_categories_from_dataframe(df)
 
     def get_statement_data(self) -> pd.DataFrame:
         return self._table_view.model().sourceModel().get_dataframe()
 
-    def add_categories(self, categories: typing.Sequence[str]):
+    def _update_categories_from_dataframe(self, df: pd.DataFrame):
+        df_categories = df['category'].unique()
+        current_categories = [self._list_widget.item(x).text() for x
+                              in range(self._list_widget.count())]
+
+        missing = list(set(df_categories) - set(current_categories))
+        self._add_categories([category for category
+                              in missing if category != ' '])
+
+    def _add_categories(self, categories: typing.Sequence[str]):
         for category in categories:
             self._list_widget.addItem(category)
 
@@ -267,7 +277,7 @@ class MainWindow(QMainWindow):
                          in range(self._list_widget.count())]
 
         if new_name not in current_items:
-            self.add_categories([new_name])
+            self._add_categories([new_name])
         else:
             QMessageBox.warning(self, "No action performed",
                                 f"Category '{new_name}' already exists.")
@@ -311,14 +321,10 @@ class MainWindow(QMainWindow):
         df.to_csv(filename, index=False)
 
 
-def show_main_window(categories: typing.Sequence[str] = None,
-                     df: pd.DataFrame = None):
+def show_main_window(df: pd.DataFrame = None):
     app = QApplication(sys.argv)
     window = MainWindow()
 
-    if categories is not None:
-        window.add_categories(categories)
-
     if df is not None:
         window.set_statement_data(df)
 
@@ -335,7 +341,7 @@ def main():
 
     df = pd.read_csv("res/bank_statement_2023_categorized_renamed.csv")
 
-    show_main_window(categories, df)
+    show_main_window(df)
 
 
 if __name__ == "__main__":