diff --git a/.github/workflows/test_endpoints.yaml b/.github/workflows/test_endpoints.yaml
index 8a0cab59b1..d76f420ffa 100644
--- a/.github/workflows/test_endpoints.yaml
+++ b/.github/workflows/test_endpoints.yaml
@@ -58,7 +58,7 @@ jobs:
         echo "PYTHONPATH=/github/workspace/env/site-packages:${{ env.PYTHONPATH}}" >> $GITHUB_ENV
 
     - name: Checks for new endpoints against AWS WAF rules
-      uses: cds-snc/notification-utils/.github/actions/waffles@a6ed8d1bc1b70780a204912e4266b1981b330bae # 52.0.4
+      uses: cds-snc/notification-utils/.github/actions/waffles@08ba5512ae392390b6c991042858f3cbe4e8aa95 # 52.0.11
       with:
         app-loc: '/github/workspace'
         app-libs: '/github/workspace/env/site-packages'
diff --git a/app/main/views/send.py b/app/main/views/send.py
index d11efe2b74..8b38b29326 100644
--- a/app/main/views/send.py
+++ b/app/main/views/send.py
@@ -35,6 +35,7 @@
 
 from app import (
     current_service,
+    get_current_locale,
     job_api_client,
     notification_api_client,
     redis_client,
@@ -628,7 +629,7 @@ def send_test_preview(service_id, template_id, filetype):
     return TemplatePreview.from_utils_template(template, filetype, page=request.args.get("page"))
 
 
-def _check_messages(service_id, template_id, upload_id, preview_row, letters_as_pdf=False):
+def _check_messages(service_id, template_id, upload_id, preview_row, letters_as_pdf=False, user_language="en"):
     try:
         # The happy path is that the job doesn’t already exist, so the
         # API will return a 404 and the client will raise HTTPError.
@@ -692,6 +693,7 @@ def _check_messages(service_id, template_id, upload_id, preview_row, letters_as_
         remaining_messages=recipients_remaining_messages,
         international_sms=current_service.has_permission("international_sms"),
         max_rows=get_csv_max_rows(service_id),
+        user_language=user_language,
     )
 
     if request.args.get("from_test"):
@@ -764,7 +766,8 @@ def _check_messages(service_id, template_id, upload_id, preview_row, letters_as_
 )
 @user_has_permissions("send_messages", restrict_admin_usage=True)
 def check_messages(service_id, template_id, upload_id, row_index=2):
-    data = _check_messages(service_id, template_id, upload_id, row_index)
+    current_lang = get_current_locale(current_app)
+    data = _check_messages(service_id, template_id, upload_id, row_index, user_language=current_lang)
     all_statistics_daily = template_statistics_client.get_template_statistics_for_service(service_id, limit_days=1)
     data["stats_daily"] = aggregate_notifications_stats(all_statistics_daily)
     data["time_to_reset"] = get_limit_reset_time_et()
@@ -1142,9 +1145,10 @@ def get_sms_sender_from_session():
 
 
 def get_spreadsheet_column_headings_from_template(template):
+    current_lang = get_current_locale(current_app)
     column_headings = []
 
-    for column_heading in first_column_headings[template.template_type] + list(template.placeholders):
+    for column_heading in first_column_headings[current_lang][template.template_type] + list(template.placeholders):
         if column_heading not in Columns.from_keys(column_headings):
             column_headings.append(column_heading)
 
diff --git a/poetry.lock b/poetry.lock
index 249239f8c8..e47ed34d7e 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -1455,7 +1455,7 @@ requests = ">=2.0.0"
 
 [[package]]
 name = "notifications-utils"
-version = "52.0.9"
+version = "52.0.11"
 description = "Shared python code for Notification - Provides logging utils etc."
 category = "main"
 optional = false
@@ -1489,8 +1489,8 @@ werkzeug = "2.3.7"
 [package.source]
 type = "git"
 url = "https://github.com/cds-snc/notifier-utils.git"
-reference = "52.0.9"
-resolved_reference = "f63ebcc2868839ee0a7b3bb7c4f2b77164130c35"
+reference = "52.0.11"
+resolved_reference = "08ba5512ae392390b6c991042858f3cbe4e8aa95"
 
 [[package]]
 name = "openpyxl"
@@ -2564,4 +2564,4 @@ testing = ["coverage (>=5.0.3)", "zope.event", "zope.testing"]
 [metadata]
 lock-version = "2.0"
 python-versions = "~3.10.8"
-content-hash = "2dd2004c68a9bd24a649847213a046c3c0f9487398903c0b6853a8a889837982"
+content-hash = "c0ce490148b66505860c4cf997491b6733410a9e75dd01e50398f69205fe3d2f"
diff --git a/pyproject.toml b/pyproject.toml
index c2d7c9d24f..8c3f6694dc 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -60,7 +60,7 @@ awscli-cwlogs = "^1.4.6"
 # Putting upgrade on hold due to v1.0.0 using sha512 instead of sha1 by default
 itsdangerous = "2.1.2"  # pyup: <1.0.0
 
-notifications-utils = {git = "https://github.com/cds-snc/notifier-utils.git", rev = "52.0.9"}
+notifications-utils = {git = "https://github.com/cds-snc/notifier-utils.git", rev = "52.0.11"}
 
 rsa = "^4.1" # not directly required, pinned by Snyk to avoid a vulnerability
 unidecode = "^1.3.6"
diff --git a/tests/app/main/views/test_send.py b/tests/app/main/views/test_send.py
index d015de22c4..39d9e59444 100644
--- a/tests/app/main/views/test_send.py
+++ b/tests/app/main/views/test_send.py
@@ -2124,37 +2124,6 @@ def test_test_message_can_only_be_sent_now(
     assert 'name="scheduled_for"' not in content
 
 
-def test_letter_can_only_be_sent_now(
-    client_request,
-    mocker,
-    mock_get_live_service,
-    mock_get_service_letter_template,
-    mock_get_users_by_service,
-    mock_get_service_statistics,
-    mock_get_template_statistics,
-    mock_s3_set_metadata,
-    mock_get_job_doesnt_exist,
-    mock_get_jobs,
-    fake_uuid,
-):
-    mocker.patch(
-        "app.main.views.send.s3download",
-        return_value="addressline1, addressline2, postcode\na,b,c",
-    )
-    mocker.patch("app.main.views.send.set_metadata_on_csv_upload")
-    mocker.patch("app.main.views.send.get_page_count_for_letter", return_value=1)
-
-    page = client_request.get(
-        "main.check_messages",
-        service_id=SERVICE_ONE_ID,
-        upload_id=fake_uuid,
-        template_id=fake_uuid,
-    )
-
-    assert 'name="scheduled_for"' not in page
-    assert normalize_spaces(page.select_one("[type=submit]").text) == ("Send all now")
-
-
 @pytest.mark.parametrize("when", ["", "2016-08-25T13:04:21.767198"])
 def test_create_job_should_call_api(
     client_request,
@@ -2650,127 +2619,6 @@ def test_check_messages_shows_trial_mode_error(
     )
 
 
-@pytest.mark.parametrize(
-    "restricted, error_should_be_shown",
-    [
-        (True, True),
-        (False, False),
-    ],
-)
-@pytest.mark.parametrize(
-    "number_of_rows, expected_error_message",
-    [
-        (1, "You cannot send this letter"),
-        (11, "You cannot send these letters"),  # Less than trial mode limit
-        (111, "You cannot send these letters"),  # More than trial mode limit
-    ],
-)
-def test_check_messages_shows_trial_mode_error_for_letters(
-    client_request,
-    service_one,
-    mock_get_service_letter_template,
-    mock_has_permissions,
-    mock_get_users_by_service,
-    mock_get_service_statistics,
-    mock_get_template_statistics,
-    mock_get_job_doesnt_exist,
-    mock_get_jobs,
-    mock_s3_set_metadata,
-    fake_uuid,
-    mocker,
-    restricted,
-    error_should_be_shown,
-    number_of_rows,
-    expected_error_message,
-):
-    service_one["restricted"] = restricted
-    mocker.patch("app.service_api_client.get_service", return_value={"data": service_one})
-
-    mocker.patch(
-        "app.main.views.send.s3download",
-        return_value="\n".join(
-            ["address_line_1,address_line_2,postcode,"] + ["First Last,    123 Street,    SW1 1AA"] * number_of_rows
-        ),
-    )
-    mocker.patch(
-        "app.main.views.send.get_page_count_for_letter",
-        return_value=3,
-    )
-
-    with client_request.session_transaction() as session:
-        session["file_uploads"] = {
-            fake_uuid: {
-                "template_id": "",
-            }
-        }
-
-    page = client_request.get(
-        "main.check_messages",
-        service_id=SERVICE_ONE_ID,
-        template_id=fake_uuid,
-        upload_id=fake_uuid,
-        _test_page_title=False,
-    )
-
-    error = page.select(".banner-dangerous")
-
-    if error_should_be_shown:
-        assert normalize_spaces(error[0].text) == ("{} " "In trial mode, you can only preview how your letters will look").format(
-            expected_error_message
-        )
-    else:
-        assert not error
-
-    assert len(page.select(".letter img")) == 3
-
-
-def test_check_messages_shows_data_errors_before_trial_mode_errors_for_letters(
-    mocker,
-    client_request,
-    mock_get_service_letter_template,
-    mock_has_permissions,
-    mock_get_users_by_service,
-    mock_get_service_statistics,
-    mock_get_template_statistics,
-    mock_get_job_doesnt_exist,
-    mock_get_jobs,
-    fake_uuid,
-):
-    mocker.patch(
-        "app.main.views.send.s3download",
-        return_value="\n".join(
-            ["address_line_1,address_line_2,postcode,"]
-            + ["              ,              ,11SW1 1AA"]
-            + ["              ,              ,11SW1 1AA"]
-        ),
-    )
-
-    mocker.patch(
-        "app.main.views.send.get_page_count_for_letter",
-        return_value=5,
-    )
-
-    with client_request.session_transaction() as session:
-        session["file_uploads"] = {
-            fake_uuid: {
-                "template_id": "",
-                "original_file_name": "example.xlsx",
-            }
-        }
-
-    page = client_request.get(
-        "main.check_messages",
-        service_id=SERVICE_ONE_ID,
-        template_id=fake_uuid,
-        upload_id=fake_uuid,
-        _test_page_title=False,
-        original_file_name="example.xlsx",
-    )
-
-    assert normalize_spaces(page.find(role="alert").text) == ("Enter missing data in 2 rows")
-    assert not page.select(".table-field-index a")
-
-
 @pytest.mark.parametrize(
     "uploaded_file_name",
     (
@@ -2895,157 +2743,6 @@ def test_check_messages_adds_sender_id_in_session_to_metadata(
     )
 
 
-@pytest.mark.parametrize(
-    "extra_args",
-    (
-        {},
-        {"from_test": True},
-    ),
-)
-def test_letters_from_csv_files_dont_have_download_link(
-    client_request,
-    mocker,
-    mock_get_service,
-    mock_get_service_letter_template,
-    mock_has_permissions,
-    fake_uuid,
-    mock_get_users_by_service,
-    mock_get_service_statistics,
-    mock_get_template_statistics,
-    mock_get_job_doesnt_exist,
-    mock_get_jobs,
-    mock_s3_set_metadata,
-    extra_args,
-):
-    mocker.patch(
-        "app.main.views.send.s3download",
-        return_value="""
-        address_line_1,address_line_2,postcode,
-        First Last,    123 Street,    SW1 1AA
-    """,
-    )
-
-    mocker.patch(
-        "app.main.views.send.get_page_count_for_letter",
-        return_value=5,
-    )
-
-    with client_request.session_transaction() as session:
-        session["file_uploads"] = {
-            fake_uuid: {
-                "template_id": "",
-            }
-        }
-
-    page = client_request.get(
-        "main.check_messages",
-        service_id=SERVICE_ONE_ID,
-        template_id=fake_uuid,
-        upload_id=fake_uuid,
-        _test_page_title=False,
-        **extra_args,
-    )
-
-    assert normalize_spaces(page.select_one(".banner-dangerous").text) == normalize_spaces(
-        "You cannot send this letter " "In trial mode, you can only preview how your letters will look"
-    )
-
-    assert len(page.select(".letter img")) == 5
-    assert not page.select("a[download]")
-
-
-@pytest.mark.parametrize("restricted", [True, False])
-def test_one_off_letters_have_download_link(
-    client_request,
-    mocker,
-    api_user_active,
-    mock_get_service_letter_template,
-    mock_has_permissions,
-    fake_uuid,
-    mock_get_users_by_service,
-    mock_get_service_statistics,
-    mock_get_template_statistics,
-    restricted,
-    service_one,
-):
-    service_one["restricted"] = restricted
-    mocker.patch("app.service_api_client.get_service", return_value={"data": service_one})
-
-    mocker.patch(
-        "app.main.views.send.get_page_count_for_letter",
-        return_value=5,
-    )
-
-    with client_request.session_transaction() as session:
-        session["recipient"] = None
-        session["placeholders"] = {
-            "address_line_1": "First Last",
-            "address_line_2": "123 Street",
-            "postcode": "SW1 1AA",
-        }
-
-    page = client_request.get(
-        "main.check_notification",
-        service_id=SERVICE_ONE_ID,
-        template_id=fake_uuid,
-        _test_page_title=False,
-    )
-
-    assert len(page.select(".letter img")) == 5
-
-    assert page.select_one("a[download]")["href"] == url_for(
-        "main.check_notification_preview",
-        service_id=SERVICE_ONE_ID,
-        template_id=fake_uuid,
-        filetype="pdf",
-    )
-    assert page.select_one("a[download]").text == "Download as a PDF"
-
-
-def test_send_one_off_letter_errors_in_trial_mode(
-    client_request,
-    mocker,
-    mock_get_service,
-    mock_get_service_letter_template,
-    mock_has_permissions,
-    fake_uuid,
-    mock_get_users_by_service,
-    mock_get_service_statistics,
-    mock_get_template_statistics,
-    mock_get_job_doesnt_exist,
-    mock_s3_set_metadata,
-):
-    mocker.patch(
-        "app.main.views.send.get_page_count_for_letter",
-        return_value=5,
-    )
-
-    with client_request.session_transaction() as session:
-        session["recipient"] = None
-        session["placeholders"] = {
-            "address_line_1": "First Last",
-            "address_line_2": "123 Street",
-            "postcode": "SW1 1AA",
-        }
-
-    page = client_request.get(
-        "main.check_notification",
-        service_id=SERVICE_ONE_ID,
-        template_id=fake_uuid,
-        _test_page_title=False,
-    )
-
-    assert normalize_spaces(page.select(".banner-dangerous")) == normalize_spaces(
-        "You cannot send this letter " "In trial mode, you can only preview how your letters will look"
-    )
-
-    assert len(page.select(".letter img")) == 5
-
-    assert not page.select("[type=submit]")
-    assert page.select_one(".back-link").text == "Back"
-    assert page.select_one("a[download]").text == "Download as a PDF"
-
-
 def test_check_messages_shows_over_max_row_error(
     client_request,
     mock_get_users_by_service,