diff --git a/app/assets/stylesheets/components/formatting-example.scss b/app/assets/stylesheets/components/formatting-example.scss
index 2878e01551..62b83e12e6 100644
--- a/app/assets/stylesheets/components/formatting-example.scss
+++ b/app/assets/stylesheets/components/formatting-example.scss
@@ -12,3 +12,23 @@
 code.lang-md {
   @include govuk-font(19);
 }
+
+code.lang-py {
+    background: govuk-colour("light-grey");
+    padding: 3px 5px;
+    border-radius: 1px;
+    font-family: monaco, Consolas, "Lucida Console", monospace;
+    font-size: 15px;
+    font-size: 0.9375rem;
+    line-height: 1.4;
+    overflow-wrap: break-word;
+    word-wrap: break-word;
+    -ms-word-break: break-all;
+    word-break: break-all;
+    word-break: break-word;
+
+    @include govuk-media-query(tablet) {
+      font-size: 16px;
+      font-size: 1rem;
+    }
+}
\ No newline at end of file
diff --git a/app/templates/views/guidance/using-notify/delivery-times.html b/app/templates/views/guidance/using-notify/delivery-times.html
index 73e9190f10..d078a8ed07 100644
--- a/app/templates/views/guidance/using-notify/delivery-times.html
+++ b/app/templates/views/guidance/using-notify/delivery-times.html
@@ -35,9 +35,23 @@ <h2 id="letters" class="heading-medium">Letters</h2>
   <p class="govuk-body">First class letters are delivered one day after they’re dispatched. Second class letters are delivered 2 days after they’re dispatched. Royal Mail delivers from Monday to Saturday, excluding bank holidays.</p>
   <p class="govuk-body">Letters to Europe are delivered 3 to 5 days after they’re dispatched. Letters sent anywhere else in the world take 5 to 7 days to arrive.</p>
 
-  <h3 id="returned-mail" class="heading-small">Undelivered letters and returned mail</h3>
-  <p class="govuk-body">Every letter we send includes our printer’s address on the back of the envelope. It’s not possible to customise the return address.</p>
-  <p class="govuk-body">Returned mail is destroyed by our printer.</p>
-  <p class="govuk-body">Each letter has a unique ID. Our printer sends us the ID of every letter they destroy. We’ll contact you if the IDs match any of your letters. This is a partly manual process, so it can take a few weeks.</p>
+  <h2 id="returned-mail" class="heading-medium">Returned letters</h2>
+  <p class="govuk-body">Every letter we send includes our print provider’s address on the back of the envelope. You cannot customise the return address.</p>
+  <p class="govuk-body">Undelivered letters are returned to our print provider and destroyed.</p>
+  <p class="govuk-body">You can see a report of returned letters on the dashboard.</p>
+  <h3 id="identify-returned-letters" class="heading-small">Identify the returned letters</h3>
+ <p class="govuk-body">To help you identify what letters are returned, the report will show details such as the:
+ </p>
+ <ul class="govuk-list govuk-list--bullet">
+   <li>template ID</li>
+   <li>date the letter was sent</li>
+   <li>a reference for each letter if you include either:
+       <ul class="govuk-list govuk-list--bullet">
+           <li>a column called ‘reference’ in the list of addresses you upload</li>
+           <li>the <code class="lang-py">reference</code> argument when making an API call if you use the <a class="govuk-link govuk-link--no-visited-state">Notify API</a> </li>
+       </ul>
+   </li>
+
+ </ul>
 
 {% endblock %}