diff --git a/lib/tasks/recalculate_irproduct_values.rake b/lib/tasks/recalculate_irproduct_values.rake
new file mode 100644
index 000000000..63af0f239
--- /dev/null
+++ b/lib/tasks/recalculate_irproduct_values.rake
@@ -0,0 +1,18 @@
+desc "Forces to recalculate irproduct values"
+task recalculate_irproduct_values: :environment do
+  LettingsLog.exportable.where(rent_type: [3, 4, 5]).where(irproduct: nil).each do |log| # irproduct was never set
+    Rails.logger.info("Could not update irroduct for LettingsLog #{log.id}") unless log.update(values_updated_at: Time.zone.now)
+  end
+  LettingsLog.exportable.where(rent_type: 3).where.not(irproduct: 1).each do |log| # irproduct was set wrong
+    Rails.logger.info("Could not update irproduct for LettingsLog #{log.id}") unless log.update(values_updated_at: Time.zone.now)
+  end
+  LettingsLog.exportable.where(rent_type: 4).where.not(irproduct: 2).each do |log| # irproduct was set wrong
+    Rails.logger.info("Could not update irproduct for LettingsLog #{log.id}") unless log.update(values_updated_at: Time.zone.now)
+  end
+  LettingsLog.exportable.where(rent_type: 5).where.not(irproduct: 3).each do |log| # irproduct was set wrong
+    Rails.logger.info("Could not update irproduct for LettingsLog #{log.id}") unless log.update(values_updated_at: Time.zone.now)
+  end
+  LettingsLog.exportable.where.not(rent_type: [3, 4, 5]).where.not(irproduct: nil).each do |log| # irproduct was set when it should have been nil
+    Rails.logger.info("Could not update irproduct for LettingsLog #{log.id}") unless log.update(values_updated_at: Time.zone.now)
+  end
+end
diff --git a/spec/lib/tasks/recalculate_irproduct_values_spec.rb b/spec/lib/tasks/recalculate_irproduct_values_spec.rb
new file mode 100644
index 000000000..957496fa0
--- /dev/null
+++ b/spec/lib/tasks/recalculate_irproduct_values_spec.rb
@@ -0,0 +1,132 @@
+require "rails_helper"
+require "rake"
+
+RSpec.describe "recalculate_irproduct_values" do
+  describe ":recalculate_irproduct_values", type: :task do
+    subject(:task) { Rake::Task["recalculate_irproduct_values"] }
+
+    before do
+      Rake.application.rake_require("tasks/recalculate_irproduct_values")
+      Rake::Task.define_task(:environment)
+      task.reenable
+    end
+
+    context "when the rake task is run" do
+      let!(:lettings_log) { create(:lettings_log, :completed, values_updated_at: nil) }
+
+      it "updates irproduct to nil if it's set to 1 but rent type is not 3, 4 or 5" do
+        lettings_log.irproduct = 1
+        lettings_log.rent_type = 2
+        lettings_log.save!(validate: false)
+        task.invoke
+        lettings_log.reload
+        expect(lettings_log.irproduct).to eq(nil)
+        expect(lettings_log.values_updated_at).not_to be_nil
+      end
+
+      it "updates irproduct to nil if it's set to 2 but rent type is not 3, 4 or 5" do
+        lettings_log.irproduct = 2
+        lettings_log.rent_type = 2
+        lettings_log.save!(validate: false)
+        task.invoke
+        lettings_log.reload
+        expect(lettings_log.irproduct).to eq(nil)
+        expect(lettings_log.values_updated_at).not_to be_nil
+      end
+
+      it "updates irproduct to nil if it's set to 3 but rent type is not 3, 4 or 5" do
+        lettings_log.irproduct = 3
+        lettings_log.rent_type = 2
+        lettings_log.save!(validate: false)
+        task.invoke
+        lettings_log.reload
+        expect(lettings_log.irproduct).to eq(nil)
+        expect(lettings_log.values_updated_at).not_to be_nil
+      end
+
+      it "updates irproduct to 1 if it's set to nil but rent type is 3" do
+        lettings_log.irproduct = nil
+        lettings_log.rent_type = 3
+        lettings_log.save!(validate: false)
+        task.invoke
+        lettings_log.reload
+        expect(lettings_log.irproduct).to eq(1)
+        expect(lettings_log.values_updated_at).not_to be_nil
+      end
+
+      it "updates irproduct to 1 if it's set to something else but rent type is 3" do
+        lettings_log.irproduct = 2
+        lettings_log.rent_type = 3
+        lettings_log.save!(validate: false)
+        task.invoke
+        lettings_log.reload
+        expect(lettings_log.irproduct).to eq(1)
+        expect(lettings_log.values_updated_at).not_to be_nil
+      end
+
+      it "updates irproduct to 2 if it's set to nil but rent type is 4" do
+        lettings_log.irproduct = nil
+        lettings_log.rent_type = 4
+        lettings_log.save!(validate: false)
+        task.invoke
+        lettings_log.reload
+        expect(lettings_log.irproduct).to eq(2)
+        expect(lettings_log.values_updated_at).not_to be_nil
+      end
+
+      it "updates irproduct to 2 if it's set to something else but rent type is 4" do
+        lettings_log.irproduct = 1
+        lettings_log.rent_type = 4
+        lettings_log.save!(validate: false)
+        task.invoke
+        lettings_log.reload
+        expect(lettings_log.irproduct).to eq(2)
+        expect(lettings_log.values_updated_at).not_to be_nil
+      end
+
+      it "updates irproduct to 3 if it's set to nil but rent type is 5" do
+        lettings_log.irproduct = nil
+        lettings_log.rent_type = 5
+        lettings_log.irproduct_other = "other"
+        lettings_log.save!(validate: false)
+        task.invoke
+        lettings_log.reload
+        expect(lettings_log.irproduct).to eq(3)
+        expect(lettings_log.values_updated_at).not_to be_nil
+      end
+
+      it "updates irproduct to 3 if it's set to something else but rent type is 5" do
+        lettings_log.irproduct = 2
+        lettings_log.rent_type = 5
+        lettings_log.irproduct_other = "other"
+        lettings_log.save!(validate: false)
+        task.invoke
+        lettings_log.reload
+        expect(lettings_log.irproduct).to eq(3)
+        expect(lettings_log.values_updated_at).not_to be_nil
+      end
+
+      it "does not update irproduct if rent_type is not 3, 4 or 5 and irproduct is nil" do
+        lettings_log.irproduct = nil
+        lettings_log.rent_type = 2
+        lettings_log.save!(validate: false)
+        task.invoke
+        lettings_log.reload
+        expect(lettings_log.irproduct).to eq(nil)
+        expect(lettings_log.values_updated_at).to be_nil
+      end
+
+      it "does not update irproduct if a different validation is triggering" do
+        lettings_log.irproduct = 2
+        lettings_log.rent_type = 5
+        lettings_log.postcode_full = "invalid"
+        lettings_log.save!(validate: false)
+        expect(Rails.logger).to receive(:info).with("Could not update irproduct for LettingsLog #{lettings_log.id}")
+        task.invoke
+        lettings_log.reload
+        expect(lettings_log.irproduct).to eq(2)
+        expect(lettings_log.values_updated_at).to be_nil
+      end
+    end
+  end
+end