diff --git a/etl/epc/Record.py b/etl/epc/Record.py
index f0bbcbfa..aac22618 100644
--- a/etl/epc/Record.py
+++ b/etl/epc/Record.py
@@ -618,9 +618,11 @@ class EPCRecord:
         if not self.prepared_epc:
             raise ValueError("EPC Recrod doesn not contain epc data")
 
-        self.construction_age_band = EPCDataProcessor.clean_construction_age_band(
-            self.prepared_epc["construction-age-band"])
-        if self.construction_age_band in DATA_ANOMALY_MATCHES:
+        self.prepared_epc["construction-age-band"] = EPCDataProcessor.clean_construction_age_band(
+            self.prepared_epc["construction-age-band"]
+        )
+
+        if self.prepared_epc["construction-age-band"] in DATA_ANOMALY_MATCHES:
             if self.old_data:
                 # Take the most recent
                 max_datetime = max(
@@ -630,15 +632,17 @@ class EPCRecord:
                 most_recent = [old_record for old_record in self.old_data if
                                old_record["lodgement-datetime"] == max_datetime]
 
-                self.construction_age_band = EPCDataProcessor.clean_construction_age_band(
+                self.prepared_epc["construction-age-band"] = EPCDataProcessor.clean_construction_age_band(
                     most_recent[0]["construction-age-band"]
                 )
 
+        self.construction_age_band = self.prepared_epc["construction-age-band"]
         self.age_band = england_wales_age_band_lookup.get(self.construction_age_band)
 
         if (self.prepared_epc["transaction-type"] == "new dwelling") and (self.age_band is None):
             self.age_band = "L"
             self.construction_age_band = 'England and Wales: 2012 onwards'
+            self.prepared_epc["construction-age-band"] = self.construction_age_band
 
         if self.age_band is None:
             raise ValueError("age_band is missing")