diff --git a/app/letters/utils.py b/app/letters/utils.py
index 57395fc87..fc84b50ac 100644
--- a/app/letters/utils.py
+++ b/app/letters/utils.py
@@ -6,7 +6,7 @@ from flask import current_app
 
 from notifications_utils.s3 import s3upload
 
-from app.models import KEY_TYPE_TEST, SECOND_CLASS, RESOLVE_POSTAGE_FOR_FILE_NAME
+from app.models import KEY_TYPE_TEST, SECOND_CLASS, RESOLVE_POSTAGE_FOR_FILE_NAME, NOTIFICATION_VALIDATION_FAILED
 from app.utils import convert_utc_to_bst
 
 
@@ -48,14 +48,23 @@ def get_letter_pdf_filename(reference, crown, is_scan_letter=False, postage=SECO
     return upload_file_name
 
 
-def get_bucket_prefix_for_notification(notification, is_test_letter=False):
+def get_bucket_name_and_prefix_for_notification(notification):
+    is_test_letter = notification.key_type == KEY_TYPE_TEST and notification.template.is_precompiled_letter
+    folder = ''
+    if notification.status == NOTIFICATION_VALIDATION_FAILED:
+        bucket_name = current_app.config['INVALID_PDF_BUCKET_NAME']
+    elif is_test_letter:
+        bucket_name = current_app.config['TEST_LETTERS_BUCKET_NAME']
+    else:
+        bucket_name = current_app.config['LETTERS_PDF_BUCKET_NAME']
+        folder = '{}/'.format(notification.created_at.date())
+
     upload_file_name = PRECOMPILED_BUCKET_PREFIX.format(
-        folder='' if is_test_letter else
-               '{}/'.format(notification.created_at.date()),
+        folder=folder,
         reference=notification.reference
     ).upper()
 
-    return upload_file_name
+    return bucket_name, upload_file_name
 
 
 def get_reference_from_filename(filename):
@@ -122,18 +131,12 @@ def get_file_names_from_error_bucket():
 
 
 def get_letter_pdf(notification):
-    is_test_letter = notification.key_type == KEY_TYPE_TEST and notification.template.is_precompiled_letter
-    if is_test_letter:
-        bucket_name = current_app.config['TEST_LETTERS_BUCKET_NAME']
-    else:
-        bucket_name = current_app.config['LETTERS_PDF_BUCKET_NAME']
+    bucket_name, prefix = get_bucket_name_and_prefix_for_notification(notification)
 
     s3 = boto3.resource('s3')
     bucket = s3.Bucket(bucket_name)
 
-    item = next(x for x in bucket.objects.filter(
-        Prefix=get_bucket_prefix_for_notification(notification, is_test_letter)
-    ))
+    item = next(x for x in bucket.objects.filter(Prefix=prefix))
 
     obj = s3.Object(
         bucket_name=bucket_name,
diff --git a/tests/app/letters/test_letter_utils.py b/tests/app/letters/test_letter_utils.py
index e7068dc9f..f2077b786 100644
--- a/tests/app/letters/test_letter_utils.py
+++ b/tests/app/letters/test_letter_utils.py
@@ -7,33 +7,39 @@ from freezegun import freeze_time
 from moto import mock_s3
 
 from app.letters.utils import (
-    get_bucket_prefix_for_notification,
+    get_bucket_name_and_prefix_for_notification,
     get_letter_pdf_filename,
     get_letter_pdf,
     upload_letter_pdf,
     ScanErrorType, move_failed_pdf, get_folder_name
 )
-from app.models import KEY_TYPE_NORMAL, KEY_TYPE_TEST, PRECOMPILED_TEMPLATE_NAME
+from app.models import KEY_TYPE_NORMAL, KEY_TYPE_TEST, PRECOMPILED_TEMPLATE_NAME, NOTIFICATION_VALIDATION_FAILED
 from tests.app.db import create_notification
 
 FROZEN_DATE_TIME = "2018-03-14 17:00:00"
 
 
-@pytest.fixture()
-def sample_precompiled_letter_notification_using_test_key(sample_letter_notification):
+@pytest.fixture(name='sample_precompiled_letter_notification')
+def _sample_precompiled_letter_notification(sample_letter_notification):
     sample_letter_notification.template.hidden = True
     sample_letter_notification.template.name = PRECOMPILED_TEMPLATE_NAME
-    sample_letter_notification.key_type = KEY_TYPE_TEST
     sample_letter_notification.reference = 'foo'
     with freeze_time(FROZEN_DATE_TIME):
         sample_letter_notification.created_at = datetime.utcnow()
     return sample_letter_notification
 
 
-def test_get_bucket_prefix_for_notification_valid_notification(sample_notification):
+@pytest.fixture(name='sample_precompiled_letter_notification_using_test_key')
+def _sample_precompiled_letter_notification_using_test_key(sample_precompiled_letter_notification):
+    sample_precompiled_letter_notification.key_type = KEY_TYPE_TEST
+    return sample_precompiled_letter_notification
 
-    bucket_prefix = get_bucket_prefix_for_notification(sample_notification)
 
+def test_get_bucket_name_and_prefix_for_notification_valid_notification(sample_notification):
+
+    bucket, bucket_prefix = get_bucket_name_and_prefix_for_notification(sample_notification)
+
+    assert bucket == current_app.config['LETTERS_PDF_BUCKET_NAME']
     assert bucket_prefix == '{folder}/NOTIFY.{reference}'.format(
         folder=sample_notification.created_at.date(),
         reference=sample_notification.reference
@@ -41,19 +47,44 @@ def test_get_bucket_prefix_for_notification_valid_notification(sample_notificati
 
 
 @freeze_time(FROZEN_DATE_TIME)
-def test_get_bucket_prefix_for_notification_precompiled_letter_using_test_key(
+def test_get_bucket_name_and_prefix_for_notification_precompiled_letter_using_test_key(
     sample_precompiled_letter_notification_using_test_key
 ):
-    bucket_prefix = get_bucket_prefix_for_notification(
-        sample_precompiled_letter_notification_using_test_key, is_test_letter=True)
+    bucket, bucket_prefix = get_bucket_name_and_prefix_for_notification(
+        sample_precompiled_letter_notification_using_test_key)
 
+    assert bucket == current_app.config['TEST_LETTERS_BUCKET_NAME']
     assert bucket_prefix == 'NOTIFY.{}'.format(
         sample_precompiled_letter_notification_using_test_key.reference).upper()
 
 
-def test_get_bucket_prefix_for_notification_invalid_notification():
+@freeze_time(FROZEN_DATE_TIME)
+def test_get_bucket_name_and_prefix_for_failed_validation(sample_precompiled_letter_notification):
+    sample_precompiled_letter_notification.status = NOTIFICATION_VALIDATION_FAILED
+    bucket, bucket_prefix = get_bucket_name_and_prefix_for_notification(sample_precompiled_letter_notification)
+
+    assert bucket == current_app.config['INVALID_PDF_BUCKET_NAME']
+    assert bucket_prefix == 'NOTIFY.{}'.format(
+        sample_precompiled_letter_notification.reference).upper()
+
+
+@freeze_time(FROZEN_DATE_TIME)
+def test_get_bucket_name_and_prefix_for_test_noti_with_failed_validation(
+    sample_precompiled_letter_notification_using_test_key
+):
+    sample_precompiled_letter_notification_using_test_key.status = NOTIFICATION_VALIDATION_FAILED
+    bucket, bucket_prefix = get_bucket_name_and_prefix_for_notification(
+        sample_precompiled_letter_notification_using_test_key
+    )
+
+    assert bucket == current_app.config['INVALID_PDF_BUCKET_NAME']
+    assert bucket_prefix == 'NOTIFY.{}'.format(
+        sample_precompiled_letter_notification_using_test_key.reference).upper()
+
+
+def test_get_bucket_name_and_prefix_for_notification_invalid_notification():
     with pytest.raises(AttributeError):
-        get_bucket_prefix_for_notification(None)
+        get_bucket_name_and_prefix_for_notification(None)
 
 
 @pytest.mark.parametrize('crown_flag,expected_crown_text', [