diff --git a/app/services/csv/missing_addresses_csv_service.rb b/app/services/csv/missing_addresses_csv_service.rb
index c052f1594..e49e7ea94 100644
--- a/app/services/csv/missing_addresses_csv_service.rb
+++ b/app/services/csv/missing_addresses_csv_service.rb
@@ -1,9 +1,33 @@
 module Csv
   class MissingAddressesCsvService
-    def initialize(organisation); end
+    def initialize(organisation)
+      @organisation = organisation
+    end
 
-    def create_missing_lettings_addresses_csv; end
+    def create_missing_lettings_addresses_csv
+      CSV.generate(headers: true) do |csv|
+        csv << ["Tenancy start date", "Tenant code", "Property code", "Log owner", "Owning organisation name", "Managing organisation name", "Address line 1", "Address line 2", "Town or City", "County", "Postcode", "Local authority"]
 
-    def create_missing_sales_addresses_csv; end
+        logs_with_missing_addresses = @organisation.managed_lettings_logs.imported.filter_by_year(2023).where(needstype: 1, address_line1: nil, town_or_city: nil, uprn_known: [0, nil])
+        return if logs_with_missing_addresses.empty?
+
+        logs_with_missing_addresses.each do |log|
+          csv << [log.startdate&.to_date, log.tenancycode, log.propcode, log.created_by&.email, log.owning_organisation&.name, log.managing_organisation&.name, log.address_line1, log.address_line2, log.town_or_city, log.county, log.postcode_full, log.la]
+        end
+      end
+    end
+
+    def create_missing_sales_addresses_csv
+      CSV.generate(headers: true) do |csv|
+        csv << ["Sale completion date", "Purchaser code", "Log owner", "Owning organisation name", "Address line 1", "Address line 2", "Town or City", "County", "Postcode", "Local authority"]
+
+        logs_with_missing_addresses = @organisation.sales_logs.imported.filter_by_year(2023).where(address_line1: nil, town_or_city: nil, uprn_known: [0, nil])
+        return if logs_with_missing_addresses.empty?
+
+        logs_with_missing_addresses.each do |log|
+          csv << [log.saledate&.to_date, log.purchid, log.created_by&.email, log.owning_organisation&.name, log.address_line1, log.address_line2, log.town_or_city, log.county, log.postcode_full, log.la]
+        end
+      end
+    end
   end
 end
diff --git a/spec/fixtures/files/missing_lettings_logs_addresses.csv b/spec/fixtures/files/missing_lettings_logs_addresses.csv
new file mode 100644
index 000000000..240813911
--- /dev/null
+++ b/spec/fixtures/files/missing_lettings_logs_addresses.csv
@@ -0,0 +1,2 @@
+Tenancy start date,Tenant code,Property code,Log owner,Owning organisation name,Managing organisation name,Address line 1,Address line 2,Town or City,County,Postcode,Local authority
+2023-04-05,tenancycode,propcode,testy@example.com,Address test,Address test,,,,,,
\ No newline at end of file
diff --git a/spec/fixtures/files/missing_sales_logs_addresses.csv b/spec/fixtures/files/missing_sales_logs_addresses.csv
new file mode 100644
index 000000000..21fed20b3
--- /dev/null
+++ b/spec/fixtures/files/missing_sales_logs_addresses.csv
@@ -0,0 +1,2 @@
+Sale completion date,Purchaser code,Log owner,Owning organisation name,Address line 1,Address line 2,Town or City,County,Postcode,Local authority
+2023-04-05,purchaser code,testy@example.com,Address test,,,,,,
\ No newline at end of file
diff --git a/spec/services/csv/missing_addresses_csv_service_spec.rb b/spec/services/csv/missing_addresses_csv_service_spec.rb
new file mode 100644
index 000000000..10bae9d01
--- /dev/null
+++ b/spec/services/csv/missing_addresses_csv_service_spec.rb
@@ -0,0 +1,104 @@
+require "rails_helper"
+
+RSpec.describe Csv::MissingAddressesCsvService do
+  let(:organisation) { create(:organisation, name: "Address test") }
+  let(:user) { create(:user, organisation:, email: "testy@example.com") }
+  let(:service) { described_class.new(organisation) }
+
+  describe "#create_missing_lettings_addresses_csv" do
+    let!(:lettings_log) do
+      create(:lettings_log,
+             tenancycode: "tenancycode",
+             propcode: "propcode",
+             startdate: Time.zone.local(2023, 4, 5),
+             created_by: user,
+             owning_organisation: organisation,
+             managing_organisation: organisation,
+             address_line1: nil,
+             town_or_city: nil,
+             old_id: "old_id",
+             needstype: 1,
+             uprn_known: 0)
+    end
+
+    context "when the organisation has logs with missing addresses" do
+      it "returns a csv with relevant logs" do
+        expected_content = CSV.read("spec/fixtures/files/missing_lettings_logs_addresses.csv")
+        csv = CSV.parse(service.create_missing_lettings_addresses_csv)
+        expect(csv).to eq(expected_content)
+      end
+    end
+
+    context "when the organisation only has supported housing logs with missing addresses" do
+      before do
+        lettings_log.update!(needstype: 2)
+      end
+
+      it "returns nil" do
+        expect(service.create_missing_lettings_addresses_csv).to be_nil
+      end
+    end
+
+    context "when the organisation only has logs with missing addresses from 2022" do
+      before do
+        lettings_log.update!(startdate: Time.zone.local(2022, 4, 5))
+      end
+
+      it "returns nil" do
+        expect(service.create_missing_lettings_addresses_csv).to be_nil
+      end
+    end
+
+    context "when the organisation has any address fields filled in" do
+      before do
+        lettings_log.update!(address_line1: "address_line1")
+      end
+
+      it "returns nil" do
+        expect(service.create_missing_lettings_addresses_csv).to be_nil
+      end
+    end
+  end
+
+  describe "#create_missing_sales_addresses_csv" do
+    let!(:sales_log) do
+      create(:sales_log,
+             purchid: "purchaser code",
+             saledate: Time.zone.local(2023, 4, 5),
+             created_by: user,
+             owning_organisation: organisation,
+             address_line1: nil,
+             town_or_city: nil,
+             old_id: "old_id",
+             uprn_known: 0)
+    end
+
+    context "when the organisation has logs with missing addresses" do
+      it "returns a csv with relevant logs" do
+        expected_content = CSV.read("spec/fixtures/files/missing_sales_logs_addresses.csv")
+        csv = CSV.parse(service.create_missing_sales_addresses_csv)
+        expect(csv).to eq(expected_content)
+      end
+    end
+
+    context "when the organisation only has logs with missing addresses from 2022" do
+      before do
+        sales_log.update!(saledate: Time.zone.local(2022, 4, 5))
+      end
+
+      it "returns nil" do
+        expect(service.create_missing_sales_addresses_csv).to be_nil
+      end
+    end
+
+    context "when the organisation has any address fields filled in" do
+      before do
+        sales_log.update!(town_or_city: "town")
+      end
+
+      it "returns nil" do
+        expect(service.create_missing_sales_addresses_csv).to be_nil
+      end
+    end
+  end
+end