diff --git a/app/celery/letters_pdf_tasks.py b/app/celery/letters_pdf_tasks.py
index 1a7e61677..3d4b335aa 100644
--- a/app/celery/letters_pdf_tasks.py
+++ b/app/celery/letters_pdf_tasks.py
@@ -479,6 +479,7 @@ def update_letter_pdf_status(reference, status, billable_units, recipient_addres
         update_dict.update({'postage': postage, 'international': True})
     if recipient_address:
         update_dict['to'] = recipient_address
+        update_dict['normalised_to'] = ''.join(recipient_address.split()).lower()
     return dao_update_notifications_by_reference(
         references=[reference],
         update_dict=update_dict)[0]
diff --git a/tests/app/celery/test_letters_pdf_tasks.py b/tests/app/celery/test_letters_pdf_tasks.py
index 0abbf8792..0d2085472 100644
--- a/tests/app/celery/test_letters_pdf_tasks.py
+++ b/tests/app/celery/test_letters_pdf_tasks.py
@@ -843,6 +843,7 @@ def test_process_sanitised_letter_with_valid_letter(
     assert sample_letter_notification.status == expected_status
     assert sample_letter_notification.billable_units == 1
     assert sample_letter_notification.to == 'A. User\nThe house on the corner'
+    assert sample_letter_notification.normalised_to == 'a.userthehouseonthecorner'
 
     assert not [x for x in scan_bucket.objects.all()]
     assert not [x for x in template_preview_bucket.objects.all()]