diff --git a/app/helpers/duplicate_logs_helper.rb b/app/helpers/duplicate_logs_helper.rb
index f1efec21b..5f4e7c68a 100644
--- a/app/helpers/duplicate_logs_helper.rb
+++ b/app/helpers/duplicate_logs_helper.rb
@@ -27,4 +27,36 @@ module DuplicateLogsHelper
     first_remaining_duplicate_id = all_duplicates.map(&:id).reject { |id| id == log.id }.first
     send("#{log.model_name.param_key}_#{page_id}_path", log, referrer: "duplicate_logs", first_remaining_duplicate_id:, original_log_id:)
   end
+  
+  def duplicates_for_user(user)
+    duplicate_sets = { lettings: [], sales: [] }
+    duplicate_lettings_ids = Set.new
+    duplicate_sales_ids = Set.new
+
+    user.lettings_logs(created_by: true).each do |log|
+      next if duplicate_lettings_ids.include? log.id
+
+      duplicates = LettingsLog.filter_by_organisation(user.organisation).duplicate_logs(log)
+      next unless duplicates.any?
+
+      duplicate_ids = [log.id, *duplicates.map(&:id)]
+      duplicate_sets[:lettings] << duplicate_ids
+      duplicate_lettings_ids << duplicate_ids
+    end
+
+    user.sales_logs(created_by: true).each do |log|
+      next if duplicate_sales_ids.include? log.id
+
+      duplicates = SalesLog.filter_by_organisation(user.organisation).duplicate_logs(log)
+      next unless duplicates.any?
+
+      duplicate_ids = [log.id, *duplicates.map(&:id)]
+      duplicate_sets[:sales] << duplicate_ids
+      duplicate_sales_ids << duplicate_ids
+    end
+
+    return if duplicate_lettings_ids.empty? && duplicate_sales_ids.empty?
+
+    duplicate_sets
+  end
 end
diff --git a/app/models/log.rb b/app/models/log.rb
index dd2cc8016..e597a3bc5 100644
--- a/app/models/log.rb
+++ b/app/models/log.rb
@@ -29,6 +29,7 @@ class Log < ApplicationRecord
   scope :visible, -> { where(status: %w[not_started in_progress completed]) }
   scope :exportable, -> { where(status: %w[not_started in_progress completed deleted]) }
 
+  scope :created_by, ->(user) { where(created_by: user) }
   scope :filter_by_status, ->(status, _user = nil) { where status: }
   scope :filter_by_years, lambda { |years, _user = nil|
     first_year = years.shift
diff --git a/app/models/user.rb b/app/models/user.rb
index eccdaec47..cbaad68d3 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -75,16 +75,20 @@ class User < ApplicationRecord
   scope :deactivated, -> { where(active: false) }
   scope :active_status, -> { where(active: true).where.not(last_sign_in_at: nil) }
 
-  def lettings_logs
-    if support?
+  def lettings_logs(created_by: false)
+    if created_by
+      LettingsLog.created_by(self)
+    elsif support?
       LettingsLog.all
     else
       LettingsLog.filter_by_organisation(organisation.absorbed_organisations + [organisation])
     end
   end
 
-  def sales_logs
-    if support?
+  def sales_logs(created_by: false)
+    if created_by
+      SalesLog.created_by(self)
+    elsif support?
       SalesLog.all
     else
       SalesLog.filter_by_owning_organisation(organisation.absorbed_organisations + [organisation])
diff --git a/spec/helpers/duplicate_logs_helper_spec.rb b/spec/helpers/duplicate_logs_helper_spec.rb
new file mode 100644
index 000000000..e03cae521
--- /dev/null
+++ b/spec/helpers/duplicate_logs_helper_spec.rb
@@ -0,0 +1,66 @@
+require "rails_helper"
+
+RSpec.describe DuplicateLogsHelper do
+  let(:org) { create(:organisation) }
+  let(:other_org) { create(:organisation) }
+  let(:current_user) { create(:user, organisation: org) }
+  let(:user_same_org) { create(:user, organisation: org) }
+  let(:user_other_org) { create(:user, organisation: other_org) }
+
+  let(:result) { duplicates_for_user(current_user) }
+
+  let!(:lettings_log) { create(:lettings_log, :duplicate, created_by: current_user) }
+  let!(:sales_log) { create(:sales_log, :duplicate, created_by: current_user) }
+
+  context "when there are no duplicates" do
+    it "returns nil" do
+      expect(result).to be nil
+    end
+  end
+
+  context "when there are duplicates in another org" do
+    before do
+      create(:lettings_log, :duplicate, created_by: user_other_org)
+      create(:sales_log, :duplicate, created_by: user_other_org)
+    end
+
+    it "returns nil" do
+      expect(result).to be nil
+    end
+  end
+
+  context "when another user in the same org has created a duplicate lettings log" do
+    let!(:duplicate_lettings_log) { create(:lettings_log, :duplicate, created_by: user_same_org) }
+
+    it "returns the ids of the duplicates in an array under the lettings key in the duplicates hash" do
+      expect(result).to be_a Hash
+      expect(result[:lettings]).to match_array [[lettings_log.id, duplicate_lettings_log.id]]
+    end
+  end
+
+  context "when another user in the same org has created a duplicate sales log" do
+    let!(:duplicate_sales_log) { create(:sales_log, :duplicate, created_by: user_same_org) }
+
+    it "returns the ids of the duplicates in an array under the sales key in the duplicates hash" do
+      expect(result).to be_a Hash
+      expect(result[:sales]).to match_array [[sales_log.id, duplicate_sales_log.id]]
+    end
+  end
+
+  context "when there are multiple sets of duplicates across lettings and sales" do
+    let!(:duplicate_lettings_log) { create(:lettings_log, :duplicate, created_by: user_same_org) }
+    let!(:duplicate_sales_log) { create(:sales_log, :duplicate, created_by: user_same_org) }
+    let!(:further_sales_log) { create(:sales_log, :duplicate, purchid: "further", created_by: current_user) }
+    let!(:further_duplicate_sales_logs) { create_list(:sales_log, 2, :duplicate, purchid: "further", created_by: user_same_org) }
+
+    it "returns them all with no repeats" do
+      expected_sales_duplicates_result = [
+        [sales_log.id, duplicate_sales_log.id],
+        [further_sales_log.id, *further_duplicate_sales_logs.map(&:id)],
+      ]
+
+      expect(result[:lettings]).to match_array [[lettings_log.id, duplicate_lettings_log.id]]
+      expect(result[:sales]).to match_array expected_sales_duplicates_result
+    end
+  end
+end