diff --git a/backend/Property.py b/backend/Property.py
index 2359ea6a..1cebc4a9 100644
--- a/backend/Property.py
+++ b/backend/Property.py
@@ -1,4 +1,5 @@
 from datetime import datetime
+from collections import Counter
 import re
 import os
 import pandas as pd
@@ -334,8 +335,24 @@ class Property(Definitions):
             raise ValueError("Property does not contain data")
 
         self.construction_age_band = DataProcessor.clean_construction_age_band(self.data["construction-age-band"])
+        if self.construction_age_band in self.DATA_ANOMALY_MATCHES:
+            if self.old_data:
+                # Take the most recent
+                max_datetime = max(
+                    [x["lodgement-datetime"] for x in self.old_data if
+                     x["construction-age-band"] not in self.DATA_ANOMALY_MATCHES]
+                )
+                most_recent = [x for x in self.old_data if x["lodgement-datetime"] == max_datetime]
+
+                self.construction_age_band = DataProcessor.clean_construction_age_band(
+                    most_recent[0]["construction-age-band"]
+                )
+
         self.age_band = england_wales_age_band_lookup.get(self.construction_age_band)
 
+        if self.age_band is None:
+            raise ValueError("age_band is missing")
+
     def set_spatial(self, spatial: pd.DataFrame):
         """
         Sets whether the property is in a conservation area given the output of the ConservationAreaClient