diff --git a/app/services/exports/organisation_export_service.rb b/app/services/exports/organisation_export_service.rb
index 2b2da71c8..afcf16cb0 100644
--- a/app/services/exports/organisation_export_service.rb
+++ b/app/services/exports/organisation_export_service.rb
@@ -56,11 +56,13 @@ module Exports
 
     def apply_cds_transformation(organisation)
       attribute_hash = organisation.attributes
-      attribute_hash["deleted_at"] = organisation.discarded_at
+      attribute_hash["deleted_at"] = organisation.discarded_at&.iso8601
       attribute_hash["dsa_signed"] = organisation.data_protection_confirmed?
-      attribute_hash["dsa_signed_at"] = organisation.data_protection_confirmation&.signed_at
+      attribute_hash["dsa_signed_at"] = organisation.data_protection_confirmation&.signed_at&.iso8601
       attribute_hash["dpo_email"] = organisation.data_protection_confirmation&.data_protection_officer_email
       attribute_hash["provider_type"] = organisation.provider_type_before_type_cast
+      attribute_hash["merge_date"] = organisation.merge_date&.iso8601
+      attribute_hash["available_from"] = organisation.available_from&.iso8601
       attribute_hash["profit_status"] = nil # will need update when we add the field to the org
       attribute_hash["group"] = nil # will need update when we add the field to the org
 
diff --git a/app/services/exports/user_export_service.rb b/app/services/exports/user_export_service.rb
index aaa30c424..707d13c14 100644
--- a/app/services/exports/user_export_service.rb
+++ b/app/services/exports/user_export_service.rb
@@ -60,6 +60,7 @@ module Exports
       attribute_hash["organisation_name"] = user.organisation.name
       attribute_hash["active"] = user.active?
       attribute_hash["phone"] = [user.phone, user.phone_extension].compact.join(" ")
+      attribute_hash["last_sign_in_at"] = user.last_sign_in_at&.iso8601
       attribute_hash
     end
   end
diff --git a/spec/fixtures/exports/user.xml b/spec/fixtures/exports/user.xml
index d29a33225..4c5286c68 100644
--- a/spec/fixtures/exports/user.xml
+++ b/spec/fixtures/exports/user.xml
@@ -6,7 +6,7 @@
     <name>Danny Rojas</name>
     <organisation_id>{organisation_id}</organisation_id>
     <sign_in_count>5</sign_in_count>
-    <last_sign_in_at/>
+    <last_sign_in_at>2022-03-03T00:00:00+00:00</last_sign_in_at>
     <role>data_provider</role>
     <phone>1234512345123 123</phone>
     <is_dpo>false</is_dpo>
diff --git a/spec/services/exports/organisation_export_service_spec.rb b/spec/services/exports/organisation_export_service_spec.rb
index 51c8fe8cf..199ee239e 100644
--- a/spec/services/exports/organisation_export_service_spec.rb
+++ b/spec/services/exports/organisation_export_service_spec.rb
@@ -17,7 +17,7 @@ RSpec.describe Exports::OrganisationExportService do
   def replace_entity_ids(organisation, export_template)
     export_template.sub!(/\{id\}/, organisation["id"].to_s)
     export_template.sub!(/\{name\}/, organisation["name"])
-    export_template.sub!(/\{dsa_signed_at\}/, organisation.data_protection_confirmation&.signed_at.to_s)
+    export_template.sub!(/\{dsa_signed_at\}/, organisation.data_protection_confirmation&.signed_at&.iso8601)
     export_template.sub!(/\{dpo_email\}/, organisation.data_protection_confirmation&.data_protection_officer_email)
   end
 
diff --git a/spec/services/exports/user_export_service_spec.rb b/spec/services/exports/user_export_service_spec.rb
index 854dd1ce7..3f4ece76d 100644
--- a/spec/services/exports/user_export_service_spec.rb
+++ b/spec/services/exports/user_export_service_spec.rb
@@ -43,7 +43,7 @@ RSpec.describe Exports::UserExportService do
     end
 
     context "and one user is available for export" do
-      let!(:user) { create(:user, organisation:, name: "Danny Rojas", phone_extension: "123") }
+      let!(:user) { create(:user, organisation:, name: "Danny Rojas", phone_extension: "123", last_sign_in_at: Time.zone.local(2022, 3, 3)) }
 
       it "generates a ZIP export file with the expected filename" do
         expect(storage_service).to receive(:write_file).with(expected_zip_filename, any_args)