diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index 5a9203da8..13edeb1f3 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -32,6 +32,20 @@ module ApplicationHelper
     !request.path.match?(/\/notifications\/\d+$/) && (authenticated_user_has_notifications? || unauthenticated_user_has_notifications?)
   end
 
+  def notification_banner
+    govuk_notification_banner(
+      title_text: "Success",
+      success: true, title_heading_level: 3,
+      title_id: "flash-notice",
+      role: "alert"
+    ) do |notification_banner|
+      notification_banner.with_heading(text: flash.notice.html_safe)
+      if flash[:notification_banner_body]
+        tag.p flash[:notification_banner_body]&.html_safe
+      end
+    end
+  end
+
 private
 
   def paginated_title(title, pagy)
diff --git a/app/views/layouts/application.html.erb b/app/views/layouts/application.html.erb
index c7d5e2230..2903d0dc6 100644
--- a/app/views/layouts/application.html.erb
+++ b/app/views/layouts/application.html.erb
@@ -120,17 +120,15 @@
 
       <main class="govuk-main-wrapper govuk-main-wrapper--auto-spacing" id="main-content" role="main">
         <% if flash.notice && !flash.notice.include?("translation missing") %>
-          <%= govuk_notification_banner(
-            title_text: "Success",
-            success: true, title_heading_level: 3,
-            title_id: "flash-notice",
-            role: "alert"
-          ) do |notification_banner|
-            notification_banner.with_heading(text: flash.notice.html_safe)
-            if flash[:notification_banner_body]
-              tag.p flash[:notification_banner_body]&.html_safe
-            end
-          end %>
+          <% if flash[:notification_banner_two_thirds] %>
+            <div class="govuk-grid-row">
+              <div class="govuk-grid-column-two-thirds-from-desktop">
+                <%= notification_banner %>
+              </div>
+            </div>
+          <% else %>
+            <%= notification_banner %>
+          <% end %>
         <% end %>
         <%= content_for?(:content) ? yield(:content) : yield %>
       </main>