diff --git a/app/controllers/delete_logs_controller.rb b/app/controllers/delete_logs_controller.rb
index fd3a0ee3b..23579ed6b 100644
--- a/app/controllers/delete_logs_controller.rb
+++ b/app/controllers/delete_logs_controller.rb
@@ -28,9 +28,9 @@ class DeleteLogsController < ApplicationController
     discard logs
     if request.referer&.include?("delete-duplicates")
       logs.each do |log|
-        log.duplicate_log_references.destroy_all
+        log.update!(duplicate_set_id: nil)
       end
-      LettingsLog.find(params["remaining_log_id"]).duplicate_log_references.destroy_all
+      LettingsLog.find(params["remaining_log_id"]).update!(duplicate_set_id: nil)
 
       redirect_to lettings_log_duplicate_logs_path(lettings_log_id: params["remaining_log_id"], original_log_id: params["original_log_id"], referrer: params[:referrer], organisation_id: params[:organisation_id]), notice: I18n.t("notification.duplicate_logs_deleted", count: logs.count, log_ids: duplicate_log_ids(logs))
     else
@@ -62,9 +62,9 @@ class DeleteLogsController < ApplicationController
     discard logs
     if request.referer&.include?("delete-duplicates")
       logs.each do |log|
-        log.duplicate_log_references.destroy_all
+        log.update!(duplicate_set_id: nil)
       end
-      SalesLog.find(params["remaining_log_id"]).duplicate_log_references.destroy_all
+      SalesLog.find(params["remaining_log_id"]).update!(duplicate_set_id: nil)
 
       redirect_to sales_log_duplicate_logs_path(sales_log_id: params["remaining_log_id"], original_log_id: params["original_log_id"], referrer: params[:referrer], organisation_id: params[:organisation_id]), notice: I18n.t("notification.duplicate_logs_deleted", count: logs.count, log_ids: duplicate_log_ids(logs))
     else
diff --git a/app/controllers/form_controller.rb b/app/controllers/form_controller.rb
index 4733fbd49..965464f35 100644
--- a/app/controllers/form_controller.rb
+++ b/app/controllers/form_controller.rb
@@ -175,12 +175,12 @@ private
       if dynamic_duplicates.count.positive?
         saved_duplicates = @log.duplicates
         unless saved_duplicates == dynamic_duplicates
-          duplicate_log_reference = DuplicateLogReference.find_or_create_by!(log_id: @log.id, log_type: @log.class.name)
+          @log.update!(duplicate_set_id: new_duplicate_set_id) if @log.duplicate_set_id.blank?
           dynamic_duplicates.each do |duplicate|
-            DuplicateLogReference.find_or_create_by!(log_id: duplicate.id, log_type: @log.class.name, duplicate_set_id: duplicate_log_reference.duplicate_set_id)
+            duplicate.update!(duplicate_set_id: @log.duplicate_set_id) if duplicate.duplicate_set_id != @log.duplicate_set_id
           end
-          return send("#{@log.class.name.underscore}_duplicate_logs_path", @log, original_log_id: @log.id)
         end
+        return send("#{@log.class.name.underscore}_duplicate_logs_path", @log, original_log_id: @log.id)
       end
     end
 
@@ -257,12 +257,12 @@ private
 
     if original_log.present? && current_user.send(class_name.pluralize).duplicate_logs(original_log).count.positive?
       unless current_user.send(class_name.pluralize).duplicate_logs(@log).count.positive?
-        remove_fixed_duplicate_log_references(@log)
+        remove_fixed_duplicate_set_ids(@log)
         flash[:notice] = deduplication_success_banner
       end
       send("#{class_name}_duplicate_logs_path", original_log, original_log_id: original_log.id, referrer: params[:referrer], organisation_id: params[:organisation_id])
     else
-      remove_fixed_duplicate_log_references(original_log)
+      remove_fixed_duplicate_set_ids(original_log)
       flash[:notice] = deduplication_success_banner
       send("#{class_name}_duplicate_logs_path", "#{class_name}_id".to_sym => from_referrer_query("first_remaining_duplicate_id"), original_log_id: from_referrer_query("original_log_id"), referrer: params[:referrer], organisation_id: params[:organisation_id])
     end
@@ -284,12 +284,19 @@ private
     I18n.t("notification.duplicate_logs.deduplication_success_banner", log_link: deduplicated_log_link, changed_question_label:).html_safe
   end
 
-  def remove_fixed_duplicate_log_references(log)
-    duplicate_log_reference = DuplicateLogReference.find_by(log_id: log.id, log_type: log.class.name)
-    return unless duplicate_log_reference
+  def remove_fixed_duplicate_set_ids(log)
+    duplicate_set_id = log.duplicate_set_id
+    return unless duplicate_set_id
 
-    duplicate_set_id = duplicate_log_reference.duplicate_set_id
-    duplicate_log_reference.destroy! if duplicate_log_reference.present?
-    DuplicateLogReference.find_by(duplicate_set_id:).destroy! if DuplicateLogReference.where(duplicate_set_id:).count == 1
+    log.update!(duplicate_set_id: nil)
+    LettingsLog.find_by(duplicate_set_id:)&.update!(duplicate_set_id: nil) if log.lettings? && LettingsLog.where(duplicate_set_id:).count == 1
+    SalesLog.find_by(duplicate_set_id:)&.update!(duplicate_set_id: nil) if log.sales? && SalesLog.where(duplicate_set_id:).count == 1
+  end
+
+  def new_duplicate_set_id
+    loop do
+      duplicate_set_id = SecureRandom.random_number(1_000_000)
+      return duplicate_set_id unless LettingsLog.exists?(duplicate_set_id:)
+    end
   end
 end
diff --git a/app/models/duplicate_log_reference.rb b/app/models/duplicate_log_reference.rb
deleted file mode 100644
index a14347959..000000000
--- a/app/models/duplicate_log_reference.rb
+++ /dev/null
@@ -1,18 +0,0 @@
-class DuplicateLogReference < ApplicationRecord
-  belongs_to :log, polymorphic: true
-
-  before_create :set_default_duplicate_set_id
-
-private
-
-  def set_default_duplicate_set_id
-    self.duplicate_set_id ||= generate_new_id
-  end
-
-  def generate_new_id
-    loop do
-      duplicate_set_id = SecureRandom.random_number(1_000_000)
-      return duplicate_set_id unless DuplicateLogReference.exists?(duplicate_set_id:)
-    end
-  end
-end
diff --git a/app/models/lettings_log.rb b/app/models/lettings_log.rb
index 28407cf28..b3ae36def 100644
--- a/app/models/lettings_log.rb
+++ b/app/models/lettings_log.rb
@@ -646,7 +646,7 @@ class LettingsLog < Log
   end
 
   def duplicates
-    LettingsLog.joins(:duplicate_log_references).where(duplicate_log_references: { duplicate_set_id: duplicate_log_references&.first&.duplicate_set_id }).where.not(id:)
+    LettingsLog.where.not(duplicate_set_id: nil).where(duplicate_set_id:).where.not(id:)
   end
 
 private
diff --git a/app/models/log.rb b/app/models/log.rb
index cccdf2fbb..8814e771d 100644
--- a/app/models/log.rb
+++ b/app/models/log.rb
@@ -7,7 +7,6 @@ class Log < ApplicationRecord
   belongs_to :created_by, class_name: "User", optional: true
   belongs_to :updated_by, class_name: "User", optional: true
   belongs_to :bulk_upload, optional: true
-  has_many :duplicate_log_references, as: :log
 
   before_save :update_status!
 
@@ -210,10 +209,6 @@ class Log < ApplicationRecord
     end
   end
 
-  def duplicate_set_id
-    duplicate_log_references.first&.duplicate_set_id
-  end
-
 private
 
   # Handle logs that are older than previous collection start date
diff --git a/app/models/sales_log.rb b/app/models/sales_log.rb
index eea3d60f6..486dcc78c 100644
--- a/app/models/sales_log.rb
+++ b/app/models/sales_log.rb
@@ -458,6 +458,6 @@ class SalesLog < Log
   end
 
   def duplicates
-    SalesLog.joins(:duplicate_log_references).where(duplicate_log_references: { duplicate_set_id: duplicate_log_references&.first&.duplicate_set_id }).where.not(id:)
+    SalesLog.where.not(duplicate_set_id: nil).where(duplicate_set_id:).where.not(id:)
   end
 end
diff --git a/app/services/exports/lettings_log_export_service.rb b/app/services/exports/lettings_log_export_service.rb
index 6cea0824b..5cc7cac00 100644
--- a/app/services/exports/lettings_log_export_service.rb
+++ b/app/services/exports/lettings_log_export_service.rb
@@ -226,7 +226,6 @@ module Exports
         attribute_hash["relat#{index}"] = "R"
         attribute_hash["ecstat#{index}"] = 10
       end
-      attribute_hash["duplicate_set_id"] = lettings_log.duplicate_set_id
 
       attribute_hash
     end
diff --git a/db/migrate/20240110101500_create_duplicate_log_references.rb b/db/migrate/20240110101500_create_duplicate_log_references.rb
deleted file mode 100644
index d12793c63..000000000
--- a/db/migrate/20240110101500_create_duplicate_log_references.rb
+++ /dev/null
@@ -1,11 +0,0 @@
-class CreateDuplicateLogReferences < ActiveRecord::Migration[7.0]
-  def change
-    create_table :duplicate_log_references do |t|
-      t.integer :duplicate_set_id
-      t.integer :log_id
-      t.string :log_type
-
-      t.timestamps
-    end
-  end
-end
diff --git a/db/migrate/20240118183843_add_duplicate_set_id.rb b/db/migrate/20240118183843_add_duplicate_set_id.rb
new file mode 100644
index 000000000..6d58ebd00
--- /dev/null
+++ b/db/migrate/20240118183843_add_duplicate_set_id.rb
@@ -0,0 +1,6 @@
+class AddDuplicateSetId < ActiveRecord::Migration[7.0]
+  def change
+    add_column :lettings_logs, :duplicate_set_id, :integer
+    add_column :sales_logs, :duplicate_set_id, :integer
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 242205d2c..f12d36ced 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.0].define(version: 2024_01_10_101500) do
+ActiveRecord::Schema[7.0].define(version: 2024_01_18_183843) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
 
@@ -63,14 +63,6 @@ ActiveRecord::Schema[7.0].define(version: 2024_01_10_101500) do
     t.index ["organisation_id"], name: "index_data_protection_confirmations_on_organisation_id"
   end
 
-  create_table "duplicate_log_references", force: :cascade do |t|
-    t.integer "duplicate_set_id"
-    t.integer "log_id"
-    t.string "log_type"
-    t.datetime "created_at", null: false
-    t.datetime "updated_at", null: false
-  end
-
   create_table "la_rent_ranges", force: :cascade do |t|
     t.integer "ranges_rent_id"
     t.integer "lettype"
@@ -310,6 +302,7 @@ ActiveRecord::Schema[7.0].define(version: 2024_01_10_101500) do
     t.integer "supcharg_value_check"
     t.integer "scharge_value_check"
     t.integer "pscharge_value_check"
+    t.integer "duplicate_set_id"
     t.index ["bulk_upload_id"], name: "index_lettings_logs_on_bulk_upload_id"
     t.index ["created_by_id"], name: "index_lettings_logs_on_created_by_id"
     t.index ["location_id"], name: "index_lettings_logs_on_location_id"
@@ -471,6 +464,8 @@ ActiveRecord::Schema[7.0].define(version: 2024_01_10_101500) do
     t.string "reader_type", null: false
     t.bigint "reader_id"
     t.datetime "timestamp", precision: nil, null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
     t.index ["readable_type", "readable_id"], name: "index_read_marks_on_readable_type_and_readable_id"
     t.index ["reader_id", "reader_type", "readable_type", "readable_id"], name: "read_marks_reader_readable_index", unique: true
     t.index ["reader_type", "reader_id"], name: "index_read_marks_on_reader_type_and_reader_id"
@@ -656,6 +651,7 @@ ActiveRecord::Schema[7.0].define(version: 2024_01_10_101500) do
     t.integer "old_form_id"
     t.datetime "values_updated_at"
     t.bigint "managing_organisation_id"
+    t.integer "duplicate_set_id"
     t.index ["bulk_upload_id"], name: "index_sales_logs_on_bulk_upload_id"
     t.index ["created_by_id"], name: "index_sales_logs_on_created_by_id"
     t.index ["managing_organisation_id"], name: "index_sales_logs_on_managing_organisation_id"
diff --git a/lib/tasks/set_duplicate_references.rake b/lib/tasks/set_duplicate_references.rake
index cf3d1932b..fb01c3950 100644
--- a/lib/tasks/set_duplicate_references.rake
+++ b/lib/tasks/set_duplicate_references.rake
@@ -2,19 +2,19 @@ desc "Set duplicate references for sales and lettings logs"
 task set_duplicate_references: :environment do
   SalesLog.filter_by_year(2023).duplicate_sets.each do |duplicate_set|
     duplicate_set_id = generate_new_duplicate_set_id
-    next if duplicate_set.any? { |log_id| DuplicateLogReference.exists?(log_id:, log_type: "SalesLog") }
+    next if duplicate_set.any? { |_log_id| SalesLog.exists?(duplicate_set_id:) }
 
     duplicate_set.each do |log_id|
-      DuplicateLogReference.create(log_id:, log_type: "SalesLog", duplicate_set_id:)
+      SalesLog.find(log_id).update!(duplicate_set_id:)
     end
   end
 
   LettingsLog.filter_by_year(2023).duplicate_sets.each do |duplicate_set|
     duplicate_set_id = generate_new_duplicate_set_id
-    next if duplicate_set.any? { |log_id| DuplicateLogReference.exists?(log_id:, log_type: "LettingsLog") }
+    next if duplicate_set.any? { |_log_id| LettingsLog.exists?(duplicate_set_id:) }
 
     duplicate_set.each do |log_id|
-      DuplicateLogReference.create(log_id:, log_type: "LettingsLog", duplicate_set_id:)
+      LettingsLog.find(log_id).update!(duplicate_set_id:)
     end
   end
 end
@@ -22,6 +22,6 @@ end
 def generate_new_duplicate_set_id
   loop do
     duplicate_set_id = SecureRandom.random_number(1_000_000)
-    return duplicate_set_id unless DuplicateLogReference.exists?(duplicate_set_id:)
+    return duplicate_set_id unless LettingsLog.exists?(duplicate_set_id:)
   end
 end
diff --git a/spec/factories/duplicate_log_reference.rb b/spec/factories/duplicate_log_reference.rb
deleted file mode 100644
index bb5a5c3dd..000000000
--- a/spec/factories/duplicate_log_reference.rb
+++ /dev/null
@@ -1,9 +0,0 @@
-FactoryBot.define do
-  factory :duplicate_log_reference do
-    log_id { 1 }
-    log_type { "SalesLog" }
-    duplicate_set_id { nil }
-    created_at { Time.zone.today }
-    updated_at { Time.zone.today }
-  end
-end
diff --git a/spec/features/form/form_navigation_spec.rb b/spec/features/form/form_navigation_spec.rb
index 3ac0328f1..256b16d74 100644
--- a/spec/features/form/form_navigation_spec.rb
+++ b/spec/features/form/form_navigation_spec.rb
@@ -178,28 +178,25 @@ RSpec.describe "Form Navigation" do
   end
 
   describe "fixing duplicate logs" do
-    let(:lettings_log) { create(:lettings_log, :duplicate, created_by: user) }
-    let(:second_log) { create(:lettings_log, :duplicate, created_by: user) }
-
-    before do
-      create(:duplicate_log_reference, log_id: id, log_type: "LettingsLog")
-      create(:duplicate_log_reference, log_id: second_log.id, log_type: "LettingsLog")
-    end
+    let!(:lettings_log) { create(:lettings_log, :duplicate, created_by: user, duplicate_set_id: 1) }
+    let!(:second_log) { create(:lettings_log, :duplicate, created_by: user, duplicate_set_id: 1) }
 
     it "shows a correct cancel link" do
-      expect(DuplicateLogReference.count).to eq(2)
+      expect(lettings_log.duplicates.count).to eq(1)
       visit("lettings-logs/#{id}/tenant-code-test?first_remaining_duplicate_id=#{second_log.id}&original_log_id=#{id}&referrer=duplicate_logs")
       click_link(text: "Cancel")
       expect(page).to have_current_path("/lettings-logs/#{id}/duplicate-logs?original_log_id=#{id}")
-      expect(DuplicateLogReference.count).to eq(2)
+      lettings_log.reload
+      expect(lettings_log.duplicates.count).to eq(1)
     end
 
     it "shows a correct Save Changes buttons" do
-      expect(DuplicateLogReference.count).to eq(2)
+      expect(lettings_log.duplicates.count).to eq(1)
       visit("lettings-logs/#{id}/tenant-code-test?first_remaining_duplicate_id=#{id}&original_log_id=#{id}&referrer=duplicate_logs")
       click_button(text: "Save changes")
       expect(page).to have_current_path("/lettings-logs/#{id}/duplicate-logs?original_log_id=#{id}&referrer=duplicate_logs")
-      expect(DuplicateLogReference.count).to eq(2)
+      lettings_log.reload
+      expect(lettings_log.duplicates.count).to eq(1)
     end
   end
 end
diff --git a/spec/features/lettings_log_spec.rb b/spec/features/lettings_log_spec.rb
index cb3e74449..f5aefb6e4 100644
--- a/spec/features/lettings_log_spec.rb
+++ b/spec/features/lettings_log_spec.rb
@@ -459,9 +459,11 @@ RSpec.describe "Lettings Log Features" do
       end
 
       it "allows keeping the original log and deleting duplicates" do
-        expect(DuplicateLogReference.count).to eq(2)
         lettings_log.reload
+        duplicate_log.reload
         expect(lettings_log.duplicates.count).to eq(1)
+        expect(lettings_log.duplicate_set_id).not_to be_nil
+        expect(duplicate_log.duplicate_set_id).not_to be_nil
         expect(lettings_log.duplicates).to include(duplicate_log)
 
         expect(page).to have_current_path("/lettings-logs/#{lettings_log.id}/duplicate-logs?original_log_id=#{lettings_log.id}")
@@ -477,8 +479,13 @@ RSpec.describe "Lettings Log Features" do
         expect(page).not_to have_link("Keep this log and delete duplicates")
         expect(page).to have_link("Back to Log #{lettings_log.id}", href: "/lettings-logs/#{lettings_log.id}")
 
-        expect(DuplicateLogReference.count).to eq(0)
+        lettings_log.reload
+        duplicate_log.reload
+
         expect(lettings_log.duplicates.count).to eq(0)
+        expect(duplicate_log.duplicates.count).to eq(0)
+        expect(lettings_log.duplicate_set_id).to be_nil
+        expect(duplicate_log.duplicate_set_id).to be_nil
       end
 
       it "allows changing answers on remaining original log" do
@@ -491,9 +498,11 @@ RSpec.describe "Lettings Log Features" do
       end
 
       it "allows keeping the duplicate log and deleting the original one" do
-        expect(DuplicateLogReference.count).to eq(2)
+        lettings_log.reload
         duplicate_log.reload
-        expect(duplicate_log.duplicates.count).to eq(1)
+        expect(lettings_log.duplicates.count).to eq(1)
+        expect(lettings_log.duplicate_set_id).not_to be_nil
+        expect(duplicate_log.duplicate_set_id).not_to be_nil
         expect(duplicate_log.duplicates).to include(lettings_log)
 
         expect(page).to have_current_path("/lettings-logs/#{lettings_log.id}/duplicate-logs?original_log_id=#{lettings_log.id}")
@@ -509,8 +518,13 @@ RSpec.describe "Lettings Log Features" do
         expect(page).not_to have_link("Keep this log and delete duplicates")
         expect(page).to have_link("Back to lettings logs", href: "/lettings-logs")
 
-        expect(DuplicateLogReference.count).to eq(0)
+        lettings_log.reload
+        duplicate_log.reload
+
+        expect(lettings_log.duplicates.count).to eq(0)
         expect(duplicate_log.duplicates.count).to eq(0)
+        expect(lettings_log.duplicate_set_id).to be_nil
+        expect(duplicate_log.duplicate_set_id).to be_nil
       end
 
       it "allows changing answers to remaining duplicate log" do
@@ -523,9 +537,11 @@ RSpec.describe "Lettings Log Features" do
       end
 
       it "allows deduplicating logs by changing the answers on the duplicate log" do
-        expect(DuplicateLogReference.count).to eq(2)
         lettings_log.reload
+        duplicate_log.reload
         expect(lettings_log.duplicates.count).to eq(1)
+        expect(lettings_log.duplicate_set_id).not_to be_nil
+        expect(duplicate_log.duplicate_set_id).not_to be_nil
         expect(lettings_log.duplicates).to include(duplicate_log)
 
         expect(page).to have_current_path("/lettings-logs/#{lettings_log.id}/duplicate-logs?original_log_id=#{lettings_log.id}")
@@ -538,8 +554,13 @@ RSpec.describe "Lettings Log Features" do
         expect(page).to have_content("Log #{duplicate_log.id} is no longer a duplicate and has been removed from the list")
         expect(page).to have_content("You changed the tenant code.")
 
-        expect(DuplicateLogReference.count).to eq(0)
+        lettings_log.reload
+        duplicate_log.reload
+
+        expect(lettings_log.duplicates.count).to eq(0)
         expect(duplicate_log.duplicates.count).to eq(0)
+        expect(lettings_log.duplicate_set_id).to be_nil
+        expect(duplicate_log.duplicate_set_id).to be_nil
       end
 
       it "allows deduplicating logs by changing the answers on the original log" do
@@ -551,8 +572,8 @@ RSpec.describe "Lettings Log Features" do
         expect(page).to have_css(".govuk-notification-banner.govuk-notification-banner--success")
         expect(page).to have_content("Log #{lettings_log.id} is no longer a duplicate and has been removed from the list")
         expect(page).to have_content("You changed the tenant code.")
-        expect(DuplicateLogReference.count).to eq(0)
         expect(duplicate_log.duplicates.count).to eq(0)
+        expect(duplicate_log.duplicate_set_id).to be_nil
       end
     end
   end
diff --git a/spec/features/sales_log_spec.rb b/spec/features/sales_log_spec.rb
index 3bfaf3705..83fd2f458 100644
--- a/spec/features/sales_log_spec.rb
+++ b/spec/features/sales_log_spec.rb
@@ -198,9 +198,12 @@ RSpec.describe "Sales Log Features" do
     end
 
     it "allows keeping the original log and deleting duplicates" do
-      expect(DuplicateLogReference.count).to eq(2)
       sales_log.reload
+      duplicate_log.reload
       expect(sales_log.duplicates.count).to eq(1)
+      expect(duplicate_log.duplicates.count).to eq(1)
+      expect(sales_log.duplicate_set_id).not_to be_nil
+      expect(duplicate_log.duplicate_set_id).not_to be_nil
       expect(sales_log.duplicates).to include(duplicate_log)
 
       expect(page).to have_current_path("/sales-logs/#{sales_log.id}/duplicate-logs?original_log_id=#{sales_log.id}")
@@ -216,8 +219,13 @@ RSpec.describe "Sales Log Features" do
       expect(page).not_to have_link("Keep this log and delete duplicates")
       expect(page).to have_link("Back to Log #{sales_log.id}", href: "/sales-logs/#{sales_log.id}")
 
-      expect(DuplicateLogReference.count).to eq(0)
+      sales_log.reload
+      duplicate_log.reload
+
       expect(sales_log.duplicates.count).to eq(0)
+      expect(duplicate_log.duplicates.count).to eq(0)
+      expect(sales_log.duplicate_set_id).to be_nil
+      expect(duplicate_log.duplicate_set_id).to be_nil
     end
 
     it "allows changing answer on remaining original log" do
@@ -230,9 +238,12 @@ RSpec.describe "Sales Log Features" do
     end
 
     it "allows keeping the duplicate log and deleting the original one" do
-      expect(DuplicateLogReference.count).to eq(2)
+      sales_log.reload
       duplicate_log.reload
+      expect(sales_log.duplicates.count).to eq(1)
       expect(duplicate_log.duplicates.count).to eq(1)
+      expect(sales_log.duplicate_set_id).not_to be_nil
+      expect(duplicate_log.duplicate_set_id).not_to be_nil
       expect(duplicate_log.duplicates).to include(sales_log)
 
       expect(page).to have_current_path("/sales-logs/#{sales_log.id}/duplicate-logs?original_log_id=#{sales_log.id}")
@@ -248,8 +259,13 @@ RSpec.describe "Sales Log Features" do
       expect(page).not_to have_link("Keep this log and delete duplicates")
       expect(page).to have_link("Back to sales logs", href: "/sales-logs")
 
-      expect(DuplicateLogReference.count).to eq(0)
+      sales_log.reload
+      duplicate_log.reload
+
+      expect(sales_log.duplicates.count).to eq(0)
       expect(duplicate_log.duplicates.count).to eq(0)
+      expect(sales_log.duplicate_set_id).to be_nil
+      expect(duplicate_log.duplicate_set_id).to be_nil
     end
 
     it "allows changing answers on remaining duplicate log" do
@@ -262,9 +278,12 @@ RSpec.describe "Sales Log Features" do
     end
 
     it "allows deduplicating logs by changing the answers on the duplicate log" do
-      expect(DuplicateLogReference.count).to eq(2)
       sales_log.reload
+      duplicate_log.reload
       expect(sales_log.duplicates.count).to eq(1)
+      expect(duplicate_log.duplicates.count).to eq(1)
+      expect(sales_log.duplicate_set_id).not_to be_nil
+      expect(duplicate_log.duplicate_set_id).not_to be_nil
       expect(sales_log.duplicates).to include(duplicate_log)
 
       expect(page).to have_current_path("/sales-logs/#{sales_log.id}/duplicate-logs?original_log_id=#{sales_log.id}")
@@ -277,8 +296,13 @@ RSpec.describe "Sales Log Features" do
       expect(page).to have_content("Log #{duplicate_log.id} is no longer a duplicate and has been removed from the list")
       expect(page).to have_content("You changed the purchaser code.")
 
-      expect(DuplicateLogReference.count).to eq(0)
+      sales_log.reload
+      duplicate_log.reload
+
+      expect(sales_log.duplicates.count).to eq(0)
       expect(duplicate_log.duplicates.count).to eq(0)
+      expect(sales_log.duplicate_set_id).to be_nil
+      expect(duplicate_log.duplicate_set_id).to be_nil
     end
 
     it "allows deduplicating logs by changing the answers on the original log" do
@@ -291,8 +315,10 @@ RSpec.describe "Sales Log Features" do
       expect(page).to have_content("Log #{sales_log.id} is no longer a duplicate and has been removed from the list")
       expect(page).to have_content("You changed the purchaser code.")
 
-      expect(DuplicateLogReference.count).to eq(0)
+      expect(sales_log.duplicates.count).to eq(0)
       expect(duplicate_log.duplicates.count).to eq(0)
+      expect(sales_log.duplicate_set_id).to be_nil
+      expect(duplicate_log.duplicate_set_id).to be_nil
     end
   end
 end
diff --git a/spec/fixtures/exports/general_needs_log.xml b/spec/fixtures/exports/general_needs_log.xml
index 1a0ed7197..f1f6a2723 100644
--- a/spec/fixtures/exports/general_needs_log.xml
+++ b/spec/fixtures/exports/general_needs_log.xml
@@ -144,6 +144,7 @@
     <county/>
     <discarded_at/>
     <creation_method>1</creation_method>
+    <duplicate_set_id/>
     <formid>{id}</formid>
     <owningorgid>{owning_org_id}</owningorgid>
     <owningorgname>DLUHC</owningorgname>
@@ -156,7 +157,6 @@
     <log_id>{log_id}</log_id>
     <created_by>test1@example.com</created_by>
     <amended_by/>
-    <duplicate_set_id/>
     <providertype>1</providertype>
   </form>
 </forms>
diff --git a/spec/fixtures/exports/general_needs_log_23_24.xml b/spec/fixtures/exports/general_needs_log_23_24.xml
index 3efc705cd..19f6c8c79 100644
--- a/spec/fixtures/exports/general_needs_log_23_24.xml
+++ b/spec/fixtures/exports/general_needs_log_23_24.xml
@@ -145,6 +145,7 @@
     <county/>
     <discarded_at/>
     <creation_method>1</creation_method>
+    <duplicate_set_id/>
     <formid>{id}</formid>
     <owningorgid>{owning_org_id}</owningorgid>
     <owningorgname>DLUHC</owningorgname>
@@ -157,7 +158,6 @@
     <log_id>{log_id}</log_id>
     <created_by>test1@example.com</created_by>
     <amended_by/>
-    <duplicate_set_id/>
     <providertype>1</providertype>
   </form>
 </forms>
diff --git a/spec/fixtures/exports/supported_housing_logs.xml b/spec/fixtures/exports/supported_housing_logs.xml
index eb91ac60c..018c158b0 100644
--- a/spec/fixtures/exports/supported_housing_logs.xml
+++ b/spec/fixtures/exports/supported_housing_logs.xml
@@ -143,6 +143,7 @@
     <county/>
     <discarded_at/>
     <creation_method>1</creation_method>
+    <duplicate_set_id/>
     <formid>{id}</formid>
     <owningorgid>{owning_org_id}</owningorgid>
     <owningorgname>DLUHC</owningorgname>
@@ -172,7 +173,6 @@
     <units>20</units>
     <location_code>{location_id}</location_code>
     <location_status>active</location_status>
-    <duplicate_set_id/>
     <providertype>1</providertype>
   </form>
 </forms>
diff --git a/spec/lib/tasks/set_duplicate_references_spec.rb b/spec/lib/tasks/set_duplicate_references_spec.rb
index 9d763ebf8..3346caa3e 100644
--- a/spec/lib/tasks/set_duplicate_references_spec.rb
+++ b/spec/lib/tasks/set_duplicate_references_spec.rb
@@ -20,15 +20,14 @@ RSpec.describe "set_duplicate_references" do
         let!(:sales_log_without_duplicates) { create(:sales_log, created_by: user) }
 
         it "creates duplicate references for sales logs" do
-          expect(DuplicateLogReference.count).to eq(0)
           expect(sales_log.duplicates.count).to eq(0)
-          expect(sales_log.duplicate_log_references).to be_empty
+          expect(sales_log.duplicate_set_id).to be_nil
           expect(duplicate_sales_log.duplicates.count).to eq(0)
-          expect(duplicate_sales_log.duplicate_log_references).to be_empty
+          expect(duplicate_sales_log.duplicate_set_id).to be_nil
           expect(second_duplicate_sales_log.duplicates.count).to eq(0)
-          expect(second_duplicate_sales_log.duplicate_log_references).to be_empty
+          expect(second_duplicate_sales_log.duplicate_set_id).to be_nil
           expect(sales_log_without_duplicates.duplicates.count).to eq(0)
-          expect(sales_log_without_duplicates.duplicate_log_references).to be_empty
+          expect(sales_log_without_duplicates.duplicate_set_id).to be_nil
 
           task.invoke
           sales_log.reload
@@ -36,32 +35,13 @@ RSpec.describe "set_duplicate_references" do
           second_duplicate_sales_log.reload
           sales_log_without_duplicates.reload
 
-          expect(DuplicateLogReference.count).to eq(3)
           expect(sales_log.duplicates.count).to eq(2)
-          expect(sales_log.duplicate_log_references.count).to eq(1)
           expect(duplicate_sales_log.duplicates.count).to eq(2)
-          expect(duplicate_sales_log.duplicate_log_references.count).to eq(1)
           expect(second_duplicate_sales_log.duplicates.count).to eq(2)
-          expect(second_duplicate_sales_log.duplicate_log_references.count).to eq(1)
           expect(sales_log_without_duplicates.duplicates.count).to eq(0)
-          expect(sales_log_without_duplicates.duplicate_log_references).to be_empty
-          expect(sales_log.duplicate_log_references.count).to eq(1)
           expect(sales_log.duplicate_set_id).to eq(duplicate_sales_log.duplicate_set_id)
           expect(sales_log.duplicate_set_id).to eq(second_duplicate_sales_log.duplicate_set_id)
         end
-
-        it "does not create the references twice" do
-          expect(DuplicateLogReference.count).to eq(0)
-
-          task.invoke
-
-          expect(DuplicateLogReference.count).to eq(3)
-
-          task.reenable
-          task.invoke
-
-          expect(DuplicateLogReference.count).to eq(3)
-        end
       end
 
       context "and there are sales duplicates in multiple organisations" do
@@ -75,41 +55,35 @@ RSpec.describe "set_duplicate_references" do
         let!(:other_sales_log_without_duplicates) { create(:sales_log, created_by: other_user) }
 
         it "creates separate duplicate references for sales logs" do
-          expect(DuplicateLogReference.count).to eq(0)
           expect(sales_log.duplicates.count).to eq(0)
-          expect(sales_log.duplicate_log_references).to be_empty
+          expect(sales_log.duplicate_set_id).to be_nil
           expect(duplicate_sales_log.duplicates.count).to eq(0)
-          expect(duplicate_sales_log.duplicate_log_references).to be_empty
+          expect(duplicate_sales_log.duplicate_set_id).to be_nil
           expect(sales_log_without_duplicates.duplicates.count).to eq(0)
-          expect(sales_log_without_duplicates.duplicate_log_references).to be_empty
+          expect(sales_log_without_duplicates.duplicate_set_id).to be_nil
 
           expect(other_sales_log.duplicates.count).to eq(0)
-          expect(other_sales_log.duplicate_log_references).to be_empty
+          expect(other_sales_log.duplicate_set_id).to be_nil
           expect(other_duplicate_sales_log.duplicates.count).to eq(0)
-          expect(other_duplicate_sales_log.duplicate_log_references).to be_empty
+          expect(other_duplicate_sales_log.duplicate_set_id).to be_nil
           expect(other_sales_log_without_duplicates.duplicates.count).to eq(0)
-          expect(other_sales_log_without_duplicates.duplicate_log_references).to be_empty
+          expect(other_sales_log_without_duplicates.duplicate_set_id).to be_nil
 
           task.invoke
           sales_log.reload
           duplicate_sales_log.reload
           sales_log_without_duplicates.reload
+          other_sales_log.reload
+          other_duplicate_sales_log.reload
 
-          expect(DuplicateLogReference.count).to eq(4)
           expect(sales_log.duplicates.count).to eq(1)
-          expect(sales_log.duplicate_log_references.count).to eq(1)
           expect(duplicate_sales_log.duplicates.count).to eq(1)
-          expect(duplicate_sales_log.duplicate_log_references.count).to eq(1)
           expect(sales_log_without_duplicates.duplicates.count).to eq(0)
-          expect(sales_log_without_duplicates.duplicate_log_references).to be_empty
           expect(sales_log.duplicate_set_id).to eq(duplicate_sales_log.duplicate_set_id)
 
           expect(other_sales_log.duplicates.count).to eq(1)
-          expect(other_sales_log.duplicate_log_references.count).to eq(1)
           expect(other_duplicate_sales_log.duplicates.count).to eq(1)
-          expect(other_duplicate_sales_log.duplicate_log_references.count).to eq(1)
           expect(other_sales_log_without_duplicates.duplicates.count).to eq(0)
-          expect(other_sales_log_without_duplicates.duplicate_log_references).to be_empty
           expect(other_sales_log.duplicate_set_id).to eq(other_duplicate_sales_log.duplicate_set_id)
           expect(other_sales_log.duplicate_set_id).not_to eq(sales_log.duplicate_set_id)
         end
@@ -128,21 +102,19 @@ RSpec.describe "set_duplicate_references" do
         end
 
         it "does not create duplicate references for sales logs" do
-          expect(DuplicateLogReference.count).to eq(0)
           expect(sales_log.duplicates.count).to eq(0)
-          expect(sales_log.duplicate_log_references).to be_empty
+          expect(sales_log.duplicate_set_id).to be_nil
           expect(duplicate_sales_log.duplicates.count).to eq(0)
-          expect(duplicate_sales_log.duplicate_log_references).to be_empty
+          expect(duplicate_sales_log.duplicate_set_id).to be_nil
 
           task.invoke
           sales_log.reload
           duplicate_sales_log.reload
 
-          expect(DuplicateLogReference.count).to eq(0)
           expect(sales_log.duplicates.count).to eq(0)
-          expect(sales_log.duplicate_log_references).to be_empty
+          expect(sales_log.duplicate_set_id).to be_nil
           expect(duplicate_sales_log.duplicates.count).to eq(0)
-          expect(duplicate_sales_log.duplicate_log_references).to be_empty
+          expect(duplicate_sales_log.duplicate_set_id).to be_nil
         end
       end
 
@@ -154,15 +126,14 @@ RSpec.describe "set_duplicate_references" do
         let!(:lettings_log_without_duplicates) { create(:lettings_log, created_by: user) }
 
         it "creates duplicate references for lettings logs" do
-          expect(DuplicateLogReference.count).to eq(0)
           expect(lettings_log.duplicates.count).to eq(0)
-          expect(lettings_log.duplicate_log_references).to be_empty
+          expect(lettings_log.duplicate_set_id).to be_nil
           expect(duplicate_lettings_log.duplicates.count).to eq(0)
-          expect(duplicate_lettings_log.duplicate_log_references).to be_empty
+          expect(duplicate_lettings_log.duplicate_set_id).to be_nil
           expect(second_duplicate_lettings_log.duplicates.count).to eq(0)
-          expect(second_duplicate_lettings_log.duplicate_log_references).to be_empty
+          expect(second_duplicate_lettings_log.duplicate_set_id).to be_nil
           expect(lettings_log_without_duplicates.duplicates.count).to eq(0)
-          expect(lettings_log_without_duplicates.duplicate_log_references).to be_empty
+          expect(lettings_log_without_duplicates.duplicate_set_id).to be_nil
 
           task.invoke
           lettings_log.reload
@@ -170,32 +141,14 @@ RSpec.describe "set_duplicate_references" do
           second_duplicate_lettings_log.reload
           lettings_log_without_duplicates.reload
 
-          expect(DuplicateLogReference.count).to eq(3)
           expect(lettings_log.duplicates.count).to eq(2)
-          expect(lettings_log.duplicate_log_references.count).to eq(1)
           expect(duplicate_lettings_log.duplicates.count).to eq(2)
-          expect(duplicate_lettings_log.duplicate_log_references.count).to eq(1)
           expect(second_duplicate_lettings_log.duplicates.count).to eq(2)
-          expect(second_duplicate_lettings_log.duplicate_log_references.count).to eq(1)
           expect(lettings_log_without_duplicates.duplicates.count).to eq(0)
-          expect(lettings_log_without_duplicates.duplicate_log_references).to be_empty
-          expect(lettings_log.duplicate_log_references.count).to eq(1)
+          expect(lettings_log_without_duplicates.duplicate_set_id).to be_nil
           expect(lettings_log.duplicate_set_id).to eq(duplicate_lettings_log.duplicate_set_id)
           expect(lettings_log.duplicate_set_id).to eq(second_duplicate_lettings_log.duplicate_set_id)
         end
-
-        it "does not create the references twice" do
-          expect(DuplicateLogReference.count).to eq(0)
-
-          task.invoke
-
-          expect(DuplicateLogReference.count).to eq(3)
-
-          task.reenable
-          task.invoke
-
-          expect(DuplicateLogReference.count).to eq(3)
-        end
       end
 
       context "and there are lettings duplicates in multiple organisations" do
@@ -209,41 +162,37 @@ RSpec.describe "set_duplicate_references" do
         let!(:other_lettings_log_without_duplicates) { create(:lettings_log, created_by: other_user) }
 
         it "creates separate duplicate references for lettings logs" do
-          expect(DuplicateLogReference.count).to eq(0)
           expect(lettings_log.duplicates.count).to eq(0)
-          expect(lettings_log.duplicate_log_references).to be_empty
+          expect(lettings_log.duplicate_set_id).to be_nil
           expect(duplicate_lettings_log.duplicates.count).to eq(0)
-          expect(duplicate_lettings_log.duplicate_log_references).to be_empty
+          expect(duplicate_lettings_log.duplicate_set_id).to be_nil
           expect(lettings_log_without_duplicates.duplicates.count).to eq(0)
-          expect(lettings_log_without_duplicates.duplicate_log_references).to be_empty
+          expect(lettings_log_without_duplicates.duplicate_set_id).to be_nil
 
           expect(other_lettings_log.duplicates.count).to eq(0)
-          expect(other_lettings_log.duplicate_log_references).to be_empty
+          expect(other_lettings_log.duplicate_set_id).to be_nil
           expect(other_duplicate_lettings_log.duplicates.count).to eq(0)
-          expect(other_duplicate_lettings_log.duplicate_log_references).to be_empty
+          expect(other_duplicate_lettings_log.duplicate_set_id).to be_nil
           expect(other_lettings_log_without_duplicates.duplicates.count).to eq(0)
-          expect(other_lettings_log_without_duplicates.duplicate_log_references).to be_empty
+          expect(other_lettings_log_without_duplicates.duplicate_set_id).to be_nil
 
           task.invoke
           lettings_log.reload
           duplicate_lettings_log.reload
           lettings_log_without_duplicates.reload
+          other_lettings_log.reload
+          other_duplicate_lettings_log.reload
 
-          expect(DuplicateLogReference.count).to eq(4)
           expect(lettings_log.duplicates.count).to eq(1)
-          expect(lettings_log.duplicate_log_references.count).to eq(1)
           expect(duplicate_lettings_log.duplicates.count).to eq(1)
-          expect(duplicate_lettings_log.duplicate_log_references.count).to eq(1)
           expect(lettings_log_without_duplicates.duplicates.count).to eq(0)
-          expect(lettings_log_without_duplicates.duplicate_log_references).to be_empty
+          expect(lettings_log_without_duplicates.duplicate_set_id).to be_nil
           expect(lettings_log.duplicate_set_id).to eq(duplicate_lettings_log.duplicate_set_id)
 
           expect(other_lettings_log.duplicates.count).to eq(1)
-          expect(other_lettings_log.duplicate_log_references.count).to eq(1)
           expect(other_duplicate_lettings_log.duplicates.count).to eq(1)
-          expect(other_duplicate_lettings_log.duplicate_log_references.count).to eq(1)
           expect(other_lettings_log_without_duplicates.duplicates.count).to eq(0)
-          expect(other_lettings_log_without_duplicates.duplicate_log_references).to be_empty
+          expect(other_lettings_log_without_duplicates.duplicate_set_id).to be_nil
           expect(other_lettings_log.duplicate_set_id).to eq(other_duplicate_lettings_log.duplicate_set_id)
           expect(other_lettings_log.duplicate_set_id).not_to eq(lettings_log.duplicate_set_id)
         end
@@ -262,21 +211,19 @@ RSpec.describe "set_duplicate_references" do
         end
 
         it "does not create duplicate references for lettings logs" do
-          expect(DuplicateLogReference.count).to eq(0)
           expect(lettings_log.duplicates.count).to eq(0)
-          expect(lettings_log.duplicate_log_references).to be_empty
+          expect(lettings_log.duplicate_set_id).to be_nil
           expect(duplicate_lettings_log.duplicates.count).to eq(0)
-          expect(duplicate_lettings_log.duplicate_log_references).to be_empty
+          expect(duplicate_lettings_log.duplicate_set_id).to be_nil
 
           task.invoke
           lettings_log.reload
           duplicate_lettings_log.reload
 
-          expect(DuplicateLogReference.count).to eq(0)
           expect(lettings_log.duplicates.count).to eq(0)
-          expect(lettings_log.duplicate_log_references).to be_empty
+          expect(lettings_log.duplicate_set_id).to be_nil
           expect(duplicate_lettings_log.duplicates.count).to eq(0)
-          expect(duplicate_lettings_log.duplicate_log_references).to be_empty
+          expect(duplicate_lettings_log.duplicate_set_id).to be_nil
         end
       end
     end
diff --git a/spec/models/duplicate_log_reference_spec.rb b/spec/models/duplicate_log_reference_spec.rb
deleted file mode 100644
index bd149c99f..000000000
--- a/spec/models/duplicate_log_reference_spec.rb
+++ /dev/null
@@ -1,89 +0,0 @@
-require "rails_helper"
-
-RSpec.describe DuplicateLogReference, type: :model do
-  context "when adding a new duplicate log" do
-    context "and duplicate_set_id is not given" do
-      let(:sales_log) { create(:sales_log) }
-
-      it "generates a new random duplicate_set_id" do
-        duplicate_log = described_class.create!(log_id: sales_log.id, log_type: "SalesLog")
-        expect(duplicate_log.duplicate_set_id).to be_a(Integer)
-      end
-    end
-
-    context "and duplicate_set_id is given" do
-      let(:sales_log) { create(:sales_log) }
-
-      it "adds correct duplicate_set_id" do
-        duplicate_log = described_class.create!(log_id: sales_log.id, log_type: "SalesLog", duplicate_set_id: 123_456)
-        expect(duplicate_log.duplicate_set_id).to eq(123_456)
-      end
-    end
-
-    context "and log does not exist" do
-      it "raises an error" do
-        expect { described_class.create!(log_id: 1, log_type: "SalesLog") }.to raise_error(ActiveRecord::RecordInvalid)
-      end
-    end
-
-    context "and log_type is invalid" do
-      let(:sales_log) { create(:sales_log) }
-
-      it "raises an error" do
-        expect { described_class.create!(log_id: sales_log.id, log_type: "SomethingElse") }.to raise_error(NameError)
-      end
-    end
-  end
-
-  context "when accessing all duplicates for a sales log" do
-    let(:sales_log) { create(:sales_log) }
-
-    context "and there are no duplicates" do
-      it "returns an empty array" do
-        expect(sales_log.duplicates).to eq([])
-      end
-    end
-
-    context "and there are duplicates" do
-      let(:other_sales_log) { create(:sales_log) }
-
-      before do
-        duplicate_log = described_class.create!(log_id: sales_log.id, log_type: "SalesLog")
-        described_class.create!(log_id: other_sales_log.id, log_type: "SalesLog", duplicate_set_id: duplicate_log.duplicate_set_id)
-        create(:sales_log)
-        create(:sales_log)
-      end
-
-      it "returns the correct duplicates" do
-        expect(sales_log.duplicates.count).to eq(1)
-        expect(sales_log.duplicates).to include(other_sales_log)
-      end
-    end
-  end
-
-  context "when accessing all duplicates for a lettings log" do
-    let(:lettings_log) { create(:lettings_log) }
-
-    context "and there are no duplicates" do
-      it "returns an empty array" do
-        expect(lettings_log.duplicates).to eq([])
-      end
-    end
-
-    context "and there are duplicates" do
-      let(:other_lettings_log) { create(:lettings_log) }
-
-      before do
-        duplicate_log = described_class.create!(log_id: lettings_log.id, log_type: "LettingsLog")
-        described_class.create!(log_id: other_lettings_log.id, log_type: "LettingsLog", duplicate_set_id: duplicate_log.duplicate_set_id)
-        create(:lettings_log)
-        create(:lettings_log)
-      end
-
-      it "returns the correct duplicates" do
-        expect(lettings_log.duplicates.count).to eq(1)
-        expect(lettings_log.duplicates).to include(other_lettings_log)
-      end
-    end
-  end
-end
diff --git a/spec/requests/form_controller_spec.rb b/spec/requests/form_controller_spec.rb
index 222ada048..54b52fc5a 100644
--- a/spec/requests/form_controller_spec.rb
+++ b/spec/requests/form_controller_spec.rb
@@ -685,7 +685,7 @@ RSpec.describe FormController, type: :request do
           end
 
           context "and duplicate logs" do
-            let(:duplicate_logs) { create_list(:sales_log, 2) }
+            let!(:duplicate_logs) { create_list(:sales_log, 2) }
 
             before do
               allow(SalesLog).to receive(:duplicate_logs).and_return(duplicate_logs)
@@ -882,8 +882,8 @@ RSpec.describe FormController, type: :request do
         end
 
         context "when the question was accessed from a duplicate logs screen" do
-          let(:lettings_log) { create(:lettings_log, :duplicate, created_by: user) }
-          let(:duplicate_log) { create(:lettings_log, :duplicate, created_by: user) }
+          let(:lettings_log) { create(:lettings_log, :duplicate, created_by: user, duplicate_set_id: 1) }
+          let(:duplicate_log) { create(:lettings_log, :duplicate, created_by: user, duplicate_set_id: 1) }
           let(:referrer) { "/lettings-logs/#{lettings_log.id}/lead-tenant-age?referrer=duplicate_logs&first_remaining_duplicate_id=#{duplicate_log.id}&original_log_id=#{lettings_log.id}" }
           let(:params) do
             {
@@ -897,14 +897,13 @@ RSpec.describe FormController, type: :request do
           end
 
           before do
-            duplicate_set_id = create(:duplicate_log_reference, log_id: lettings_log.id, log_type: "LettingsLog").duplicate_set_id
-            create(:duplicate_log_reference, log_id: duplicate_log.id, log_type: "LettingsLog", duplicate_set_id:)
             post "/lettings-logs/#{lettings_log.id}/lead-tenant-age", params:, headers: headers.merge({ "HTTP_REFERER" => referrer })
           end
 
           it "redirects back to the duplicates page for remaining duplicates" do
             expect(response).to redirect_to("/lettings-logs/#{duplicate_log.id}/duplicate-logs?original_log_id=#{lettings_log.id}")
-            expect(DuplicateLogReference.count).to eq(0)
+            expect(lettings_log.duplicates.count).to eq(0)
+            expect(duplicate_log.duplicates.count).to eq(0)
           end
 
           context "and the answer didn't change" do
@@ -921,14 +920,15 @@ RSpec.describe FormController, type: :request do
 
             it "redirects back to the duplicates page for remaining duplicates" do
               expect(response).to redirect_to("/lettings-logs/#{lettings_log.id}/duplicate-logs?original_log_id=#{lettings_log.id}")
-              expect(DuplicateLogReference.count).to eq(2)
+              expect(lettings_log.duplicates.count).to eq(1)
+              expect(duplicate_log.duplicates.count).to eq(1)
             end
           end
         end
 
         context "when the sales question was accessed from a duplicate logs screen" do
-          let(:sales_log) { create(:sales_log, :duplicate, created_by: user) }
-          let(:duplicate_log) { create(:sales_log, :duplicate, created_by: user) }
+          let!(:sales_log) { create(:sales_log, :duplicate, created_by: user, duplicate_set_id: 1) }
+          let!(:duplicate_log) { create(:sales_log, :duplicate, created_by: user, duplicate_set_id: 1) }
           let(:referrer) { "/sales-logs/#{sales_log.id}/buyer-1-age?referrer=duplicate_logs&first_remaining_duplicate_id=#{duplicate_log.id}&original_log_id=#{sales_log.id}&referrer=duplicate_logs" }
           let(:params) do
             {
@@ -942,14 +942,15 @@ RSpec.describe FormController, type: :request do
           end
 
           before do
-            duplicate_set_id = create(:duplicate_log_reference, log_id: sales_log.id, log_type: "SalesLog").duplicate_set_id
-            create(:duplicate_log_reference, log_id: duplicate_log.id, log_type: "SalesLog", duplicate_set_id:)
             post "/sales-logs/#{sales_log.id}/buyer-1-age", params:, headers: headers.merge({ "HTTP_REFERER" => referrer })
           end
 
           it "redirects back to the duplicates page for remaining duplicates" do
             expect(response).to redirect_to("/sales-logs/#{duplicate_log.id}/duplicate-logs?original_log_id=#{sales_log.id}")
-            expect(DuplicateLogReference.count).to eq(0)
+            sales_log.reload
+            duplicate_log.reload
+            expect(sales_log.duplicates.count).to eq(0)
+            expect(duplicate_log.duplicates.count).to eq(0)
           end
 
           context "and the answer didn't change" do
@@ -966,7 +967,8 @@ RSpec.describe FormController, type: :request do
 
             it "redirects back to the duplicates page for remaining duplicates" do
               expect(response).to redirect_to("/sales-logs/#{sales_log.id}/duplicate-logs?original_log_id=#{sales_log.id}")
-              expect(DuplicateLogReference.count).to eq(2)
+              expect(sales_log.duplicates.count).to eq(1)
+              expect(duplicate_log.duplicates.count).to eq(1)
             end
           end
         end
diff --git a/spec/services/csv/lettings_log_csv_service_spec.rb b/spec/services/csv/lettings_log_csv_service_spec.rb
index 8d88f471c..f3e180d51 100644
--- a/spec/services/csv/lettings_log_csv_service_spec.rb
+++ b/spec/services/csv/lettings_log_csv_service_spec.rb
@@ -171,7 +171,7 @@ RSpec.describe Csv::LettingsLogCsvService do
 
     context "when the log has a duplicate log reference" do
       before do
-        DuplicateLogReference.create!(log_id: log.id, log_type: "LettingsLog", duplicate_set_id: 12_312)
+        log.update!(duplicate_set_id: 12_312)
       end
 
       it "exports the id for under the heading 'duplicate_set_id'" do
@@ -256,7 +256,7 @@ RSpec.describe Csv::LettingsLogCsvService do
 
       context "when the log has a duplicate log reference" do
         before do
-          DuplicateLogReference.create!(log_id: log.id, log_type: "LettingsLog", duplicate_set_id: 12_312)
+          log.update!(duplicate_set_id: 12_312)
         end
 
         it "exports the id for under the heading 'duplicate_set_id'" do
diff --git a/spec/services/csv/sales_log_csv_service_spec.rb b/spec/services/csv/sales_log_csv_service_spec.rb
index e60321365..f9f545c35 100644
--- a/spec/services/csv/sales_log_csv_service_spec.rb
+++ b/spec/services/csv/sales_log_csv_service_spec.rb
@@ -166,7 +166,7 @@ RSpec.describe Csv::SalesLogCsvService do
 
     context "when the log has a duplicate log reference" do
       before do
-        DuplicateLogReference.create!(log_id: log.id, log_type: "SalesLog", duplicate_set_id: 12_312)
+        log.update!(duplicate_set_id: 12_312)
       end
 
       it "exports the id for under the heading 'duplicate_set_id'" do
@@ -226,7 +226,7 @@ RSpec.describe Csv::SalesLogCsvService do
 
     context "when the log has a duplicate log reference" do
       before do
-        DuplicateLogReference.create!(log_id: log.id, log_type: "SalesLog", duplicate_set_id: 12_312)
+        log.update!(duplicate_set_id: 12_312)
       end
 
       it "exports the id for under the heading 'duplicate_set_id'" do
diff --git a/spec/services/exports/lettings_log_export_service_spec.rb b/spec/services/exports/lettings_log_export_service_spec.rb
index 3134237ec..4e76364c4 100644
--- a/spec/services/exports/lettings_log_export_service_spec.rb
+++ b/spec/services/exports/lettings_log_export_service_spec.rb
@@ -415,11 +415,7 @@ RSpec.describe Exports::LettingsLogExportService do
     end
 
     context "and one lettings log with duplicate reference is available for export" do
-      let!(:lettings_log) { FactoryBot.create(:lettings_log, :completed, created_by: user, propcode: "123", ppostcode_full: "SE2 6RT", postcode_full: "NW1 5TY", tenancycode: "BZ737", startdate: Time.zone.local(2022, 2, 2, 10, 36, 49), voiddate: Time.zone.local(2019, 11, 3), mrcdate: Time.zone.local(2020, 5, 5, 10, 36, 49), tenancylength: 5, underoccupation_benefitcap: 4) }
-
-      before do
-        FactoryBot.create(:duplicate_log_reference, log_type: "LettingsLog", log_id: lettings_log.id, duplicate_set_id: 123)
-      end
+      let!(:lettings_log) { FactoryBot.create(:lettings_log, :completed, created_by: user, propcode: "123", ppostcode_full: "SE2 6RT", postcode_full: "NW1 5TY", tenancycode: "BZ737", startdate: Time.zone.local(2022, 2, 2, 10, 36, 49), voiddate: Time.zone.local(2019, 11, 3), mrcdate: Time.zone.local(2020, 5, 5, 10, 36, 49), tenancylength: 5, underoccupation_benefitcap: 4, duplicate_set_id: 123) }
 
       def replace_duplicate_set_id(export_file)
         export_file.sub!("<duplicate_set_id/>", "<duplicate_set_id>123</duplicate_set_id>")