diff --git a/core/views.py b/core/views.py
index fd6251a..0236a76 100644
--- a/core/views.py
+++ b/core/views.py
@@ -1254,6 +1254,13 @@ def create_receipt(request):
             # Save the receipt header (but don't commit yet — need to set user)
             receipt = form.save(commit=False)
             receipt.user = request.user
+            # Set temporary zero values so the first save doesn't fail.
+            # (subtotal and total_amount have no default in the model,
+            # so they'd be NULL — which MariaDB rejects.)
+            # We'll recalculate these properly after saving line items.
+            receipt.subtotal = Decimal('0.00')
+            receipt.vat_amount = Decimal('0.00')
+            receipt.total_amount = Decimal('0.00')
             receipt.save()
 
             # Save line items — link them to this receipt