diff --git a/app/main/views/send.py b/app/main/views/send.py
index 573ee9102..41897aa22 100644
--- a/app/main/views/send.py
+++ b/app/main/views/send.py
@@ -20,7 +20,6 @@ from notifications_utils.recipients import (
     optional_address_columns,
 )
 from orderedset import OrderedSet
-from werkzeug.routing import RequestRedirect
 from xlrd.biffh import XLRDError
 from xlrd.xldate import XLDateError
 
@@ -126,14 +125,6 @@ def send_messages(service_id, template_id):
                 Spreadsheet.from_file(form.file.data, filename=form.file.data.filename).as_dict,
                 current_app.config['AWS_REGION']
             )
-            if 'file_uploads' not in session:
-                session['file_uploads'] = {}
-            session['file_uploads'].update({
-                upload_id: {
-                    "template_id": template_id,
-                    "original_file_name": form.file.data.filename
-                }
-            })
             return redirect(url_for(
                 '.check_messages',
                 service_id=service_id,
@@ -476,15 +467,6 @@ def send_test_preview(service_id, template_id, filetype):
 
 def _check_messages(service_id, template_id, upload_id, preview_row, letters_as_pdf=False):
 
-    if not session.get('file_uploads', {}).get(upload_id):
-        # if we just return a `redirect` (302) object here, we'll get errors when we try and unpack in the
-        # check_messages route - so raise a werkzeug.routing redirect to ensure that doesn't happen.
-
-        # NOTE: this is a 301 MOVED PERMANENTLY (httpstatus.es/301), so the browser will cache this redirect, and it'll
-        # *always* happen for that browser. _check_messages is only used by endpoints that contain `upload_id`, which
-        # is a one-time-use id (that ties to a given file in S3 that is already deleted if it's not in the session)
-        raise RequestRedirect(url_for('main.send_messages', service_id=service_id, template_id=template_id))
-
     users = user_api_client.get_users_for_service(service_id=service_id)
 
     statistics = service_api_client.get_detailed_service_for_today(service_id)['data']['statistics']
@@ -499,12 +481,10 @@ def _check_messages(service_id, template_id, upload_id, preview_row, letters_as_
 
     email_reply_to = None
     sms_sender = None
-
     if db_template['template_type'] == 'email':
         email_reply_to = get_email_reply_to_address_from_session(service_id)
     elif db_template['template_type'] == 'sms':
         sms_sender = get_sms_sender_from_session(service_id)
-
     template = get_template(
         service_api_client.get_service_template(
             service_id,
@@ -552,6 +532,10 @@ def _check_messages(service_id, template_id, upload_id, preview_row, letters_as_
     elif preview_row > 2:
         abort(404)
 
+    if 'file_uploads' not in session:
+        session['file_uploads'] = {}
+    session['file_uploads'][upload_id] = {}
+
     if any(recipients) and not recipients.has_errors:
         session['file_uploads'][upload_id]['notification_count'] = len(recipients)
         session['file_uploads'][upload_id]['valid'] = True
@@ -719,12 +703,6 @@ def make_and_upload_csv_file(service_id, template):
         ).as_dict,
         current_app.config['AWS_REGION'],
     )
-    if 'file_uploads' not in session:
-        session['file_uploads'] = {}
-    session['file_uploads'][upload_id] = {
-        "template_id": template.id,
-        "original_file_name": current_app.config['TEST_MESSAGE_FILENAME']
-    }
     return redirect(url_for(
         '.check_messages',
         upload_id=upload_id,
diff --git a/tests/app/main/views/test_send.py b/tests/app/main/views/test_send.py
index dd1d1a633..0c6795a88 100644
--- a/tests/app/main/views/test_send.py
+++ b/tests/app/main/views/test_send.py
@@ -1443,9 +1443,10 @@ def test_upload_csvfile_with_valid_phone_shows_all_numbers(
         follow_redirects=True
     )
     with logged_in_client.session_transaction() as sess:
-        assert sess['file_uploads'][fake_uuid]['template_id'] == fake_uuid
-        assert 'original_file_name' not in sess['file_uploads']
+        assert 'template_id' not in sess['file_uploads'][fake_uuid]
+        assert 'original_file_name' not in sess['file_uploads'][fake_uuid]
         assert sess['file_uploads'][fake_uuid]['notification_count'] == 53
+        assert sess['file_uploads'][fake_uuid]['valid'] is True
 
     content = response.get_data(as_text=True)
     assert response.status_code == 200
@@ -2344,26 +2345,6 @@ def test_non_ascii_characters_in_letter_recipients_file_shows_error(
     assert page.find('span', class_='table-field-error-label').text == u'Can’t include П, е, т or я'
 
 
-def test_check_messages_redirects_if_no_upload_data(
-    client_request,
-    fake_uuid,
-    mock_get_service_template,
-):
-    client_request.get(
-        'main.check_messages',
-        service_id=SERVICE_ONE_ID,
-        template_id=fake_uuid,
-        upload_id=fake_uuid,
-        _expected_status=301,
-        _expected_redirect=url_for(
-            'main.send_messages',
-            service_id=SERVICE_ONE_ID,
-            template_id=fake_uuid,
-            _external=True,
-        )
-    )
-
-
 @pytest.mark.parametrize('existing_session_items', [
     {},
     {'recipient': '07700900001'},
@@ -2782,23 +2763,6 @@ def test_sms_sender_is_previewed(
 
 
 @pytest.mark.parametrize('endpoint, request_type, extra_args', [
-    (
-        'main.check_messages',
-        'GET',
-        {
-            'template_id': fake_uuid(),
-            'upload_id': fake_uuid(),
-        }
-    ),
-    (
-        'main.check_messages_preview',
-        'GET',
-        {
-            'template_id': fake_uuid(),
-            'upload_id': fake_uuid(),
-            'filetype': 'png'
-        }
-    ),
     (
         'main.start_job',
         'POST',