diff --git a/app/main/views/send.py b/app/main/views/send.py
index 557faf0ba..b806af7c5 100644
--- a/app/main/views/send.py
+++ b/app/main/views/send.py
@@ -439,7 +439,10 @@ def _check_messages(service_id, template_type, upload_id, letters_as_pdf=False):
         remaining_messages=remaining_messages,
         choose_time_form=choose_time_form,
         back_link=back_link,
-        help=get_help_argument()
+        help=get_help_argument(),
+        trying_to_send_letters_in_trial_mode=bool(
+            current_service['restricted'] and template.template_type == 'letter'
+        ),
     )
 
 
@@ -461,7 +464,7 @@ def check_messages(service_id, template_type, upload_id):
     if data['row_errors']:
         return render_template('views/check/row-errors.html', **data)
 
-    if data['errors']:
+    if data['errors'] or data['trying_to_send_letters_in_trial_mode']:
         return render_template('views/check/column-errors.html', **data)
 
     return render_template('views/check/ok.html', **data)
diff --git a/app/templates/views/check/column-errors.html b/app/templates/views/check/column-errors.html
index 5beaeb529..9dbd9a548 100644
--- a/app/templates/views/check/column-errors.html
+++ b/app/templates/views/check/column-errors.html
@@ -87,6 +87,17 @@
 
         {% include "partials/check/too-many-messages.html" %}
 
+      {% elif trying_to_send_letters_in_trial_mode %}
+
+        <h1 class='banner-title' data-module="track-error" data-error-type="Trying to send letters in trial mode" data-error-label="{{ upload_id }}">
+          You can’t send
+          {{ 'this letter' if count_of_recipients == 1 else 'these letters' }}
+        </h1>
+        <p>
+          In <a href="{{ url_for('.trial_mode') }}">trial mode</a> you
+          can only preview how your letters will look
+        </p>
+
       {% endif %}
 
       {{ skip_to_file_contents() }}
diff --git a/tests/app/main/views/test_send.py b/tests/app/main/views/test_send.py
index b323237a2..ad6ef2254 100644
--- a/tests/app/main/views/test_send.py
+++ b/tests/app/main/views/test_send.py
@@ -24,6 +24,8 @@ from tests.conftest import (
     mock_get_service_email_template,
     normalize_spaces,
     SERVICE_ONE_ID,
+    mock_get_service,
+    mock_get_live_service,
 )
 
 template_types = ['email', 'sms']
@@ -1577,6 +1579,52 @@ def test_check_messages_shows_trial_mode_error(
     )
 
 
+@pytest.mark.parametrize('service_mock, error_should_be_shown', [
+    (mock_get_service, True),
+    (mock_get_live_service, False),
+])
+def test_check_messages_shows_trial_mode_error_for_letters(
+    client_request,
+    api_user_active,
+    mock_get_service_letter_template,
+    mock_has_permissions,
+    mock_get_users_by_service,
+    mock_get_detailed_service_for_today,
+    mocker,
+    service_mock,
+    error_should_be_shown,
+):
+
+    service_mock(mocker, api_user_active)
+
+    mocker.patch('app.main.views.send.s3download', return_value='''
+        address_line_1,address_line_2,postcode,
+        First Last,    123 Street,    SW1 1AA
+    ''')
+
+    with client_request.session_transaction() as session:
+        session['upload_data'] = {'template_id': ''}
+
+    page = client_request.get(
+        'main.check_messages',
+        service_id=SERVICE_ONE_ID,
+        template_type='letter',
+        upload_id=uuid.uuid4(),
+        _test_page_title=False,
+    )
+
+    error = page.select('.banner-dangerous')
+
+    if error_should_be_shown:
+        assert normalize_spaces(error[0].text) == (
+            'You can’t send this letter '
+            'In trial mode you can only preview how your letters will look '
+            'Skip to file contents'
+        )
+    else:
+        assert not error
+
+
 def test_check_messages_shows_over_max_row_error(
     logged_in_client,
     api_user_active,