diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 78b367d80..5685796af 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -14,4 +14,8 @@ protected
   def user_for_paper_trail
     current_user
   end
+
+  def byte_order_mark
+    "\uFEFF"
+  end
 end
diff --git a/app/controllers/case_logs_controller.rb b/app/controllers/case_logs_controller.rb
index 17bae5ee8..a9b927725 100644
--- a/app/controllers/case_logs_controller.rb
+++ b/app/controllers/case_logs_controller.rb
@@ -22,7 +22,7 @@ class CaseLogsController < ApplicationController
       end
 
       format.csv do
-        send_data unpaginated_filtered_logs.to_csv(current_user), filename: "logs-#{Time.zone.now}.csv"
+        send_data byte_order_mark + unpaginated_filtered_logs.to_csv(current_user), filename: "logs-#{Time.zone.now}.csv"
       end
     end
   end
diff --git a/app/controllers/organisations_controller.rb b/app/controllers/organisations_controller.rb
index cb600b004..81ba4f737 100644
--- a/app/controllers/organisations_controller.rb
+++ b/app/controllers/organisations_controller.rb
@@ -45,7 +45,7 @@ class OrganisationsController < ApplicationController
         end
       end
       format.csv do
-        send_data unpaginated_filtered_users.to_csv, filename: "users-#{@organisation.name}-#{Time.zone.now}.csv"
+        send_data byte_order_mark + unpaginated_filtered_users.to_csv, filename: "users-#{@organisation.name}-#{Time.zone.now}.csv"
       end
     end
   end
@@ -103,7 +103,7 @@ class OrganisationsController < ApplicationController
         end
 
         format.csv do
-          send_data unpaginated_filtered_logs.to_csv, filename: "logs-#{@organisation.name}-#{Time.zone.now}.csv"
+          send_data byte_order_mark + unpaginated_filtered_logs.to_csv, filename: "logs-#{@organisation.name}-#{Time.zone.now}.csv"
         end
       end
     else
diff --git a/app/controllers/users_controller.rb b/app/controllers/users_controller.rb
index cd82742b6..9ab691a53 100644
--- a/app/controllers/users_controller.rb
+++ b/app/controllers/users_controller.rb
@@ -20,7 +20,7 @@ class UsersController < ApplicationController
       format.html
       format.csv do
         if current_user.support?
-          send_data filtered_users.to_csv, filename: "users-#{Time.zone.now}.csv"
+          send_data byte_order_mark + filtered_users.to_csv, filename: "users-#{Time.zone.now}.csv"
         else
           head :unauthorized
         end
diff --git a/spec/requests/case_logs_controller_spec.rb b/spec/requests/case_logs_controller_spec.rb
index 4ca219c67..5c4ce4dca 100644
--- a/spec/requests/case_logs_controller_spec.rb
+++ b/spec/requests/case_logs_controller_spec.rb
@@ -755,7 +755,7 @@ RSpec.describe CaseLogsController, type: :request do
 
       it "downloads a CSV file with headers" do
         csv = CSV.parse(response.body)
-        expect(csv.first.first).to eq("id")
+        expect(csv.first.first).to eq("\uFEFFid")
         expect(csv.second.first).to eq(case_log.id.to_s)
       end