diff --git a/changelog_entry.yaml b/changelog_entry.yaml
index e69de29bb..1e5cb75bf 100644
--- a/changelog_entry.yaml
+++ b/changelog_entry.yaml
@@ -0,0 +1,4 @@
+- bump: patch
+  changes:
+    fixed:
+      - Fix TypeError in uprate_rent when region.values.astype(str) returns a pandas StringArray instead of numpy array.
diff --git a/policyengine_uk/data/economic_assumptions.py b/policyengine_uk/data/economic_assumptions.py
index cc252b542..9c5f7069a 100644
--- a/policyengine_uk/data/economic_assumptions.py
+++ b/policyengine_uk/data/economic_assumptions.py
@@ -161,8 +161,9 @@ def uprate_rent(
         pass
     elif year < 2025:
         # We have regional growth rates for private rent.
+        # Convert to numpy array for vectorial parameter lookup
         regional_growth_rate = growth.ons.private_rental_prices(year)[
-            region.values.astype(str)
+            np.array(region.values.astype(str))
         ]
         current_year.household["rent"] = np.where(
             is_private_rented,