diff --git a/backend/address2UPRN/main.py b/backend/address2UPRN/main.py
index d0ba36e6..97e2037a 100644
--- a/backend/address2UPRN/main.py
+++ b/backend/address2UPRN/main.py
@@ -462,6 +462,15 @@ def handler(event, context, local=False):
                 # Validate postcode before processing
                 if not AddressMatch.is_valid_postcode(postcode):
                     logger.warning(f"Postcode {postcode} is invalid, skipping")
+                    for row in postcode_rows:
+                        results_data.append(
+                            {
+                                **row,
+                                "address2uprn_uprn": "invalid postcode",
+                                "address2uprn_address": "invalid postcode",
+                                "address2uprn_lexiscore": "invalid postcode",
+                            }
+                        )
                     continue
 
                 # Fetch EPC data once per postcode