diff --git a/app/templates/partials/jobs/notifications.html b/app/templates/partials/jobs/notifications.html
index 1b0348279..e8a3f0973 100644
--- a/app/templates/partials/jobs/notifications.html
+++ b/app/templates/partials/jobs/notifications.html
@@ -34,7 +34,7 @@
           </p>
         {% elif notifications %}
           <p class="{% if job.template_type != 'letter' %}bottom-gutter{% endif %}">
-            <a href="{{ download_link }}" download class="govuk-link govuk-link--no-visited-state heading-small">Download this report</a>
+            <a href="{{ download_link }}" download class="govuk-link govuk-link--no-visited-state heading-small">Download this report (<abbr title="Comma separated values">CSV</abbr>)</a>
             &emsp;
             <span id="time-left">{{ time_left }}</span>
           </p>
diff --git a/app/templates/views/notifications.html b/app/templates/views/notifications.html
index 4d159e63a..ed90cb23a 100644
--- a/app/templates/views/notifications.html
+++ b/app/templates/views/notifications.html
@@ -66,7 +66,7 @@
 
   {% if current_user.has_permissions('view_activity') %}
     <p class="bottom-gutter">
-      <a href="{{ download_link }}" download="download" class="govuk-link govuk-link--no-visited-state govuk-!-font-weight-bold">Download this report</a>
+      <a href="{{ download_link }}" download="download" class="govuk-link govuk-link--no-visited-state govuk-!-font-weight-bold">Download this report (<abbr title="Comma separated values">CSV</abbr>)</a>
       &emsp;
       Data available for {{ partials.service_data_retention_days }} days
     </p>
diff --git a/app/templates/views/organisations/organisation/index.html b/app/templates/views/organisations/organisation/index.html
index 3c555c3d9..bbb30ccd3 100644
--- a/app/templates/views/organisations/organisation/index.html
+++ b/app/templates/views/organisations/organisation/index.html
@@ -113,7 +113,7 @@
   {% else %}
     <div class="js-stick-at-bottom-when-scrolling">
       <p class="govuk-!-margin-bottom-1">
-        <a href="{{ download_link }}" download="download" class="govuk-link govuk-link--no-visited-state govuk-!-font-weight-bold">Download this report</a>
+        <a href="{{ download_link }}" download="download" class="govuk-link govuk-link--no-visited-state govuk-!-font-weight-bold">Download this report (<abbr title="Comma separated values">CSV</abbr>)</a>
       </p>
     </div>
   {% endif %}
diff --git a/app/templates/views/returned-letters.html b/app/templates/views/returned-letters.html
index c3fe7f3b5..b0f30118a 100644
--- a/app/templates/views/returned-letters.html
+++ b/app/templates/views/returned-letters.html
@@ -17,7 +17,7 @@
 {{ page_header('Returned letters for {}'.format(reported_at|format_date_normal)) }}
 
 <p class="bottom-gutter">
-  <a download href="{{ url_for('.returned_letters_report', service_id=current_service.id, reported_at=reported_at) }}" class="govuk-link heading-small">Download this report</a>
+  <a download href="{{ url_for('.returned_letters_report', service_id=current_service.id, reported_at=reported_at) }}" class="govuk-link heading-small">Download this report (<abbr title="Comma separated values">CSV</abbr>)</a>
 </p>
 
 <div class="dashboard-table">
diff --git a/app/templates/views/send.html b/app/templates/views/send.html
index 91a38674b..df8beb31c 100644
--- a/app/templates/views/send.html
+++ b/app/templates/views/send.html
@@ -50,7 +50,7 @@
     {% endcall %}
   </div>
   <p class="table-show-more-link">
-    <a class="govuk-link govuk-link--no-visited-state" href="{{ url_for('.get_example_csv', service_id=current_service.id, template_id=template.id) }}" download>Download this example</a>
+    <a class="govuk-link govuk-link--no-visited-state" href="{{ url_for('.get_example_csv', service_id=current_service.id, template_id=template.id) }}" download>Download this example (<abbr title="Comma separated values">CSV</abbr>)</a>
   </p>
 
   <h2 class="heading-medium">Your file will populate this template ({{ template.name }})</h2>
diff --git a/app/templates/views/uploads/contact-list/contact-list.html b/app/templates/views/uploads/contact-list/contact-list.html
index 89f126a94..56f1179b7 100644
--- a/app/templates/views/uploads/contact-list/contact-list.html
+++ b/app/templates/views/uploads/contact-list/contact-list.html
@@ -134,7 +134,7 @@
           <a class="govuk-link govuk-link--destructive" href="{{ url_for('main.delete_contact_list', service_id=current_service.id, contact_list_id=contact_list.id) }}">Delete this contact list</a>
         </span>
       {% endif %}
-      <a class="govuk-link govuk-link--no-visited-state page-footer-right-aligned-link-without-button" download href="{{ url_for('main.download_contact_list', service_id=current_service.id, contact_list_id=contact_list.id) }}">Download this contact list</a>
+      <a class="govuk-link govuk-link--no-visited-state page-footer-right-aligned-link-without-button" download href="{{ url_for('main.download_contact_list', service_id=current_service.id, contact_list_id=contact_list.id) }}">Download this contact list (<abbr title="Comma separated values">CSV</abbr>)</a>
     </div>
   </div>
 
diff --git a/tests/app/main/views/organisations/test_organisations.py b/tests/app/main/views/organisations/test_organisations.py
index 8ad264489..cee554c6e 100644
--- a/tests/app/main/views/organisations/test_organisations.py
+++ b/tests/app/main/views/organisations/test_organisations.py
@@ -666,7 +666,7 @@ def test_organisation_services_links_to_downloadable_report(
     page = client_request.get('.organisation_dashboard', org_id=ORGANISATION_ID)
 
     link_to_report = page.select_one('a[download]')
-    assert normalize_spaces(link_to_report.text) == 'Download this report'
+    assert normalize_spaces(link_to_report.text) == 'Download this report (CSV)'
     assert link_to_report.attrs["href"] == url_for(
         '.download_organisation_usage_report',
         org_id=ORGANISATION_ID,
diff --git a/tests/app/main/views/test_jobs.py b/tests/app/main/views/test_jobs.py
index 4cdbe3e86..015219b63 100644
--- a/tests/app/main/views/test_jobs.py
+++ b/tests/app/main/views/test_jobs.py
@@ -106,7 +106,7 @@ def test_should_show_page_for_one_job(
         job_id=fake_uuid,
         status=status_argument
     )
-    assert csv_link.text == 'Download this report'
+    assert csv_link.text == 'Download this report (CSV)'
     assert page.find('span', {'id': 'time-left'}).text == 'Data available for 7 days'
 
     assert normalize_spaces(page.select_one('tbody tr').text) == normalize_spaces(
diff --git a/tests/app/main/views/test_returned_letters.py b/tests/app/main/views/test_returned_letters.py
index 15b06ae51..576777295 100644
--- a/tests/app/main/views/test_returned_letters.py
+++ b/tests/app/main/views/test_returned_letters.py
@@ -146,7 +146,7 @@ def test_returned_letters_page_with_many_letters(
         expected_message
     )
     assert page.select_one('a[download]').text == (
-        'Download this report'
+        'Download this report (CSV)'
     )
     assert page.select_one('a[download]')['href'] == url_for(
         '.returned_letters_report',