diff --git a/etl/transform/types.py b/etl/transform/types.py
index cefb894..f8fe9e6 100644
--- a/etl/transform/types.py
+++ b/etl/transform/types.py
@@ -24,7 +24,7 @@ class CompanyInfo(BaseModel):
 class SurverySummaryInfo(BaseModel):
     reference_number: str
     epc_language: str
-    uprn: str
+    uprn: Optional[str] = ""
     postcode: str
     region: str
     address: str