diff --git a/app/main/forms.py b/app/main/forms.py
index 0312537ef..04c51202f 100644
--- a/app/main/forms.py
+++ b/app/main/forms.py
@@ -859,9 +859,6 @@ class LetterUploadPostageForm(StripWhitespaceForm):
         default='second',
         validators=[DataRequired()]
     )
-    file_id = HiddenField(
-        validators=[DataRequired()]
-    )
 
 
 class ForgotPasswordForm(StripWhitespaceForm):
diff --git a/app/main/views/uploads.py b/app/main/views/uploads.py
index 672f5b83c..af375dc8f 100644
--- a/app/main/views/uploads.py
+++ b/app/main/views/uploads.py
@@ -338,15 +338,13 @@ def view_letter_upload_as_preview(service_id, file_id):
         return TemplatePreview.from_valid_pdf_file(pdf_file, page)
 
 
-@main.route("/services/<uuid:service_id>/upload-letter/send", methods=['POST'])
 @main.route("/services/<uuid:service_id>/upload-letter/send/<uuid:file_id>", methods=['POST'])
 @user_has_permissions('send_messages', restrict_admin_usage=True)
 def send_uploaded_letter(service_id, file_id=None):
     if not (current_service.has_permission('letter') and current_service.has_permission('upload_letters')):
         abort(403)
 
-    form = LetterUploadPostageForm(file_id=file_id)
-    file_id = file_id or form.file_id.data
+    form = LetterUploadPostageForm()
 
     if not form.validate_on_submit():
         return uploaded_letter_preview(service_id, file_id)
diff --git a/tests/app/main/views/test_uploads.py b/tests/app/main/views/test_uploads.py
index 163a6bee2..24614b6f8 100644
--- a/tests/app/main/views/test_uploads.py
+++ b/tests/app/main/views/test_uploads.py
@@ -766,40 +766,11 @@ def test_uploaded_letter_preview_image_400s_for_bad_page_type(
     )
 
 
-def test_send_uploaded_letter_sends_letter_and_redirects_to_notification_page(mocker, service_one, client_request):
-    metadata = LetterMetadata({'filename': 'my_file.pdf', 'page_count': '1', 'status': 'valid', 'recipient': 'address'})
-
-    mocker.patch('app.main.views.uploads.get_letter_pdf_and_metadata', return_value=('file', metadata))
-    mock_send = mocker.patch('app.main.views.uploads.notification_api_client.send_precompiled_letter')
-    mocker.patch('app.main.views.uploads.get_letter_metadata', return_value=metadata)
-
-    service_one['permissions'] = ['letter', 'upload_letters']
-    file_id = 'abcd-1234'
-
-    client_request.post(
-        'main.send_uploaded_letter',
-        service_id=SERVICE_ONE_ID,
-        _data={'filename': 'my_file.pdf', 'file_id': file_id, 'postage': 'first'},
-        _expected_redirect=url_for(
-            'main.view_notification',
-            service_id=SERVICE_ONE_ID,
-            notification_id=file_id,
-            _external=True
-        )
-    )
-    mock_send.assert_called_once_with(SERVICE_ONE_ID, 'my_file.pdf', file_id, 'first', 'address')
-
-
-@pytest.mark.parametrize('form_data', (
-    {'filename': 'my_file.pdf', 'postage': 'first'},
-    {'filename': 'my_file.pdf', 'postage': 'first', 'file_id': 'Ignored in favour of URL'},
-))
-def test_send_uploaded_letter_accepts_file_id_in_url(
+def test_send_uploaded_letter_sends_letter_and_redirects_to_notification_page(
     mocker,
     service_one,
     client_request,
     fake_uuid,
-    form_data,
 ):
     metadata = LetterMetadata({'filename': 'my_file.pdf', 'page_count': '1', 'status': 'valid', 'recipient': 'address'})
 
@@ -813,7 +784,7 @@ def test_send_uploaded_letter_accepts_file_id_in_url(
         'main.send_uploaded_letter',
         service_id=SERVICE_ONE_ID,
         file_id=fake_uuid,
-        _data=form_data,
+        _data={'filename': 'my_file.pdf', 'postage': 'first'},
         _expected_redirect=url_for(
             'main.view_notification',
             service_id=SERVICE_ONE_ID,
@@ -824,31 +795,6 @@ def test_send_uploaded_letter_accepts_file_id_in_url(
     mock_send.assert_called_once_with(SERVICE_ONE_ID, 'my_file.pdf', fake_uuid, 'first', 'address')
 
 
-def test_send_uploaded_letter_needs_file_id_in_form_if_not_in_url(
-    mocker,
-    service_one,
-    client_request,
-    mock_template_preview,
-    fake_uuid,
-):
-    metadata = LetterMetadata({'filename': 'my_file.pdf', 'page_count': '1', 'status': 'valid', 'recipient': 'address'})
-
-    mock_send = mocker.patch('app.main.views.uploads.notification_api_client.send_precompiled_letter')
-    mocker.patch('app.main.views.uploads.get_letter_metadata', return_value=metadata)
-    mocker.patch('app.main.views.uploads.service_api_client.get_precompiled_template')
-
-    service_one['permissions'] = ['letter', 'upload_letters']
-
-    client_request.post(
-        'main.send_uploaded_letter',
-        service_id=SERVICE_ONE_ID,
-        _data={'filename': 'my_file.pdf', 'postage': 'first'},
-        _expected_status=200,
-        _expected_redirect=None,
-    )
-    assert mock_send.called is False
-
-
 @pytest.mark.parametrize('permissions', [
     ['email'],
     ['letter'],
@@ -859,23 +805,26 @@ def test_send_uploaded_letter_when_service_does_not_have_correct_permissions(
     service_one,
     client_request,
     permissions,
+    fake_uuid,
 ):
     mocker.patch('app.main.views.uploads.get_letter_pdf_and_metadata', return_value=('file', {'status': 'valid'}))
     mock_send = mocker.patch('app.main.views.uploads.notification_api_client.send_precompiled_letter')
 
     service_one['permissions'] = permissions
-    file_id = 'abcd-1234'
 
     client_request.post(
         'main.send_uploaded_letter',
         service_id=SERVICE_ONE_ID,
-        _data={'filename': 'my_file.pdf', 'file_id': file_id, 'postage': 'first'},
+        file_id=fake_uuid,
+        _data={'filename': 'my_file.pdf', 'postage': 'first'},
         _expected_status=403
     )
     assert not mock_send.called
 
 
-def test_send_uploaded_letter_when_metadata_states_pdf_is_invalid(mocker, service_one, client_request):
+def test_send_uploaded_letter_when_metadata_states_pdf_is_invalid(
+    mocker, service_one, client_request, fake_uuid,
+):
     mock_send = mocker.patch('app.main.views.uploads.notification_api_client.send_precompiled_letter')
     mocker.patch(
         'app.main.views.uploads.get_letter_metadata',
@@ -888,12 +837,12 @@ def test_send_uploaded_letter_when_metadata_states_pdf_is_invalid(mocker, servic
     )
 
     service_one['permissions'] = ['letter', 'upload_letters']
-    file_id = 'abcd-1234'
 
     client_request.post(
         'main.send_uploaded_letter',
         service_id=SERVICE_ONE_ID,
-        _data={'filename': 'my_file.pdf', 'file_id': file_id},
+        file_id=fake_uuid,
+        _data={'filename': 'my_file.pdf'},
         _expected_status=403
     )
     assert not mock_send.called