diff --git a/src/pipelines/shared/postprocessing/postprocessing_funcs.py b/src/pipelines/shared/postprocessing/postprocessing_funcs.py
index b258626..da86ec2 100644
--- a/src/pipelines/shared/postprocessing/postprocessing_funcs.py
+++ b/src/pipelines/shared/postprocessing/postprocessing_funcs.py
@@ -511,6 +511,10 @@ def reorder_columns(
     # Reorder columns to match column_order
     final_column_order = [col for col in column_order if col in df_copy.columns]
 
+    # Append any extra columns not in column_order (e.g. client-specific fields)
+    extra_columns = [col for col in df_copy.columns if col not in column_order]
+    final_column_order.extend(extra_columns)
+
     # Return the DataFrame with reordered columns
     return df_copy[final_column_order]