diff --git a/stats/frequency.py b/stats/frequency.py
index 0db6b30..57b1f5f 100644
--- a/stats/frequency.py
+++ b/stats/frequency.py
@@ -18,7 +18,6 @@ def _format_can_id_vec(s: pd.Series) -> pd.Series:
 def calculate_frequency(df: pd.DataFrame) -> pd.DataFrame:
     can_id_col = 'ID' if 'ID' in df.columns else 'Identifier'
     formatted = _format_can_id_vec(df[can_id_col])
-    df['Formatted_ID'] = formatted
 
     counts = formatted.value_counts()
     freq_df = pd.DataFrame({