diff --git a/backend/app/db/models/epc_property.py b/backend/app/db/models/epc_property.py
index 0bbf2add..f04741f8 100644
--- a/backend/app/db/models/epc_property.py
+++ b/backend/app/db/models/epc_property.py
@@ -18,8 +18,8 @@ class EpcPropertyModel(SQLModel, table=True):
     __tablename__ = "epc_property"
 
     id: Optional[int] = Field(default=None, primary_key=True)
-    property_id: int = Field(foreign_key="property.id", nullable=False)
-    portfolio_id: int = Field(foreign_key="portfolio.id", nullable=False)
+    property_id: Optional[int] = Field(default=None)
+    portfolio_id: Optional[int] = Field(default=None)
 
     # Identity / admin
     uprn: Optional[int] = Field(default=None)
@@ -148,8 +148,8 @@ class EpcPropertyModel(SQLModel, table=True):
     def from_epc_property_data(
         cls,
         data: EpcPropertyData,
-        property_id: int,
-        portfolio_id: int,
+        property_id: Optional[int] = None,
+        portfolio_id: Optional[int] = None,
     ) -> EpcPropertyModel:
         es = data.sap_energy_source
         h = data.sap_heating