diff --git a/app/views/root/related.raw.html.erb b/app/views/root/related.raw.html.erb
index 41e76551c..6f1984160 100644
--- a/app/views/root/related.raw.html.erb
+++ b/app/views/root/related.raw.html.erb
@@ -1,10 +1,34 @@
 <%# Whilst they are both in use, this and the test copy in slimmer should be kept in sync %>
-<% if artefact and (artefact.related_artefacts.any? or (artefact.related_external_links and artefact.related_external_links.any?)) %>
+
+<%
+  promo_target_formats = ['completed_transaction', 'transaction']
+  promo_excluded_regex = /register-to-vote/
+
+  has_promo_callout = (artefact and promo_target_formats.include?(artefact.format) and not promo_excluded_regex.match(URI.decode(artefact.slug)))
+%>
+<%# Whilst they are both in use, this and the test copy in slimmer should be kept in sync %>
+<% if artefact and (artefact.related_artefacts.any? or (artefact.related_external_links and artefact.related_external_links.any?) or has_promo_callout) %>
   <!-- related -->
   <div class="related-container">
 
     <aside class="related" id="related">
-      <% artefact.related_artefacts.group_by(&:group).each do |group, related_artefacts| %>
+
+      <% if has_promo_callout %>
+        <div class="inner group related-callout">
+          <h2 id="parent-promo">Register to vote</h2>
+          <p>You need to register if you want to vote in elections and referendums.</p>
+          <p>You can <a href="/register-to-vote?source=related">register online</a> in less than 5 minutes.</p>
+        </div>
+      <% end %>
+
+      <% related_artefacts = artefact.related_artefacts || [] %>
+
+      <%# Exclude '/register-to-vote', only if we're adding it manually (its easier to do by `content_id` than full `web_url`) %>
+      <% related_artefacts = related_artefacts.reject { |artefact|
+        artefact.content_id == "834a7921-260b-4061-9de1-edda3e998c68" and has_promo_callout
+      } %>
+
+      <% related_artefacts.group_by(&:group).each do |group, related_artefacts| %>
         <%
           section = case group
                     when 'subsection' then artefact.primary_section
@@ -12,6 +36,7 @@
                     when 'other' then { "title" => "Elsewhere on GOV.UK" }
                     end
           section = section['parent'] if artefact.format == "travel-advice" and group == "subsection"
+
         %>
         <div class="inner group related-<%= group %>">
           <% if section %>
diff --git a/test/integration/related_template_test.rb b/test/integration/related_template_test.rb
index 66949315c..68604660c 100644
--- a/test/integration/related_template_test.rb
+++ b/test/integration/related_template_test.rb
@@ -10,15 +10,15 @@ def get_template
 
   context "with related artefacts" do
     setup do
-      @related1 = stub("Artefact", :web_url => "http://www.example.com/foo", :title => "Foo", :group => "subsection")
-      @related2 = stub("Artefact", :web_url => "http://www.example.com/bar", :title => "Bar", :group => "section")
-      @related3 = stub("Artefact", :web_url => "http://www.example.com/baz", :title => "Baz", :group => "other")
+      @related1 = stub("Artefact", web_url: "http://www.example.com/foo", title: "Foo", group: "subsection", content_id: 1)
+      @related2 = stub("Artefact", web_url: "http://www.example.com/bar", title: "Bar", group: "section", content_id: 2)
+      @related3 = stub("Artefact", web_url: "http://www.example.com/baz", title: "Baz", group: "other", content_id: 3)
       @artefact = stub("Artefact",
-        :related_artefacts => [@related1, @related2, @related3],
-        :related_external_links => [],
-        :primary_root_section => { "title" => "Section", "content_with_tag" => { "web_url" => "/browse/section" }},
-        :primary_section => { "title" => "Sub-section", "content_with_tag" => { "web_url" => "/browse/section/subsection" } },
-        :format => "guide"
+        related_artefacts: [@related1, @related2, @related3],
+        related_external_links: [],
+        primary_root_section: { "title" => "Section", "content_with_tag" => { "web_url" => "/browse/section" } },
+        primary_section: { "title" => "Sub-section", "content_with_tag" => { "web_url" => "/browse/section/subsection" } },
+        format: "guide"
       )
     end
 
@@ -148,11 +148,11 @@ def get_template
   context "adding related_external_links with no internal related links" do
     setup do
       @artefact = stub("Artefact",
-        :related_artefacts => [],
-        :related_external_links => [],
-        :primary_root_section => { "title" => "Section", "content_with_tag" => { "web_url" => "/browse/section" }},
-        :primary_section => { "title" => "Sub-section", "content_with_tag" => { "web_url" => "/browse/section/subsection" } },
-        :format => "guide"
+        related_artefacts: [],
+        related_external_links: [],
+        primary_root_section: { "title" => "Section", "content_with_tag" => { "web_url" => "/browse/section" } },
+        primary_section: { "title" => "Sub-section", "content_with_tag" => { "web_url" => "/browse/section/subsection" } },
+        format: "guide"
       )
     end
 
@@ -207,7 +207,7 @@ def get_template
   should "be blank with an artefact with no related_artefacts or related_external_links" do
     template = get_template
 
-    artefact = stub("Artefact", :related_artefacts => [], :related_external_links => [])
+    artefact = stub("Artefact", related_artefacts: [], related_external_links: [], format: "smart_answer")
     result = ERB.new(template).result(binding)
 
     assert_match /\A\s+\z/, result
@@ -216,9 +216,24 @@ def get_template
   should "be blank with no related_artefacts and nil related_external_links" do
     template = get_template
 
-    artefact = stub("Artefact", :related_artefacts => [], :related_external_links => nil)
+    artefact = stub("Artefact", related_artefacts: [], related_external_links: nil, format: "smart_answer")
     result = ERB.new(template).result(binding)
 
     assert_match /\A\s+\z/, result
   end
+
+  context "adding promo block to related links" do
+    should "have promo block for target formats" do
+      artefact = stub("Artefact", related_artefacts: [], related_external_links: nil, format: "completed_transaction", slug: "book-theory-test")
+      result = ERB.new(get_template).result(binding)
+      doc = Nokogiri::HTML.parse(result)
+      assert doc.at_css("h2#parent-promo")
+    end
+
+    should "not have promo block for artefact with excluded path" do
+      artefact = stub("Artefact", related_artefacts: [], related_external_links: nil, format: "completed_transaction", slug: "done/register-to-vote")
+      result = ERB.new(get_template).result(binding)
+      assert_match(/\A\s+\z/, result)
+    end
+  end
 end