diff --git a/app/models/validations/sales/soft_validations.rb b/app/models/validations/sales/soft_validations.rb
index 468a7ce00..f7db3f82e 100644
--- a/app/models/validations/sales/soft_validations.rb
+++ b/app/models/validations/sales/soft_validations.rb
@@ -115,7 +115,17 @@ module Validations::Sales::SoftValidations
   end
 
   def discounted_ownership_value_invalid?
-    false
+    return unless saledate && collection_start_year <= 2023
+    return unless value && deposit && ownershipsch
+    return unless mortgage || mortgageused == 2
+    return unless discount || grant || type == 29
+
+    discount_amount = discount ? value * discount / 100 : 0
+    grant_amount = grant || 0
+    mortgage_amount = mortgage || 0
+    value_with_discount = (value - discount_amount)
+
+    mortgage_amount + deposit + grant_amount != value_with_discount && discounted_ownership_sale?
   end
 
 private
diff --git a/spec/models/validations/sales/soft_validations_spec.rb b/spec/models/validations/sales/soft_validations_spec.rb
index dc8bbfedd..f3a5ca91b 100644
--- a/spec/models/validations/sales/soft_validations_spec.rb
+++ b/spec/models/validations/sales/soft_validations_spec.rb
@@ -798,4 +798,119 @@ RSpec.describe Validations::Sales::SoftValidations do
       expect(record).to be_person_3_student_not_child
     end
   end
+  
+  describe "#discounted_ownership_value_invalid?" do
+    context "when grant is routed to" do
+      let(:record) { FactoryBot.build(:sales_log, mortgage: 10_000, deposit: 5_000, value: 30_000, ownershipsch: 2, type: 8, saledate: Time.zone.local(2023, 4, 3)) }
+
+      context "and not provided" do
+        before do
+          record.grant = nil
+        end
+
+        it "returns false" do
+          expect(record).not_to be_discounted_ownership_value_invalid
+        end
+      end
+
+      context "and is provided" do
+        it "returns true if mortgage, deposit and grant total does not equal market value" do
+          record.grant = 3_000
+          expect(record).to be_discounted_ownership_value_invalid
+        end
+
+        it "returns false if mortgage, deposit and grant total equals market value" do
+          record.grant = 15_000
+          expect(record).not_to be_discounted_ownership_value_invalid
+        end
+      end
+    end
+
+    context "when discount is routed to" do
+      let(:record) { FactoryBot.build(:sales_log, mortgage: 10_000, deposit: 5_000, value: 30_000, ownershipsch: 2, type: 9, saledate: Time.zone.local(2023, 4, 3)) }
+
+      context "and not provided" do
+        before do
+          record.discount = nil
+        end
+
+        it "returns false" do
+          expect(record).not_to be_discounted_ownership_value_invalid
+        end
+      end
+
+      context "and is provided" do
+        it "returns true if mortgage and deposit total does not equal market value - discount" do
+          record.discount = 10
+          expect(record).to be_discounted_ownership_value_invalid
+        end
+
+        it "returns false if mortgage and deposit total equals market value - discount" do
+          record.discount = 50
+          expect(record).not_to be_discounted_ownership_value_invalid
+        end
+      end
+    end
+
+    context "when neither discount nor grant is routed to" do
+      let(:record) { FactoryBot.build(:sales_log, mortgage: 10_000, value: 30_000, ownershipsch: 2, type: 29, saledate: Time.zone.local(2023, 4, 3)) }
+
+      it "returns true if mortgage and deposit total does not equal market value" do
+        record.deposit = 2_000
+        expect(record).to be_discounted_ownership_value_invalid
+      end
+
+      it "returns false if mortgage and deposit total equals market value" do
+        record.deposit = 20_000
+        expect(record).not_to be_discounted_ownership_value_invalid
+      end
+    end
+
+    context "when mortgage is routed to" do
+      let(:record) { FactoryBot.build(:sales_log, mortgageused: 1, deposit: 5_000, grant: 3_000, value: 20_000, discount: 10, ownershipsch: 2, saledate: Time.zone.local(2023, 4, 3)) }
+
+      context "and not provided" do
+        before do
+          record.mortgage = nil
+        end
+
+        it "returns false" do
+          expect(record).not_to be_discounted_ownership_value_invalid
+        end
+      end
+
+      context "and is provided" do
+        it "returns true if mortgage, grant and deposit total does not equal market value - discount" do
+          record.mortgage = 10
+          expect(record).to be_discounted_ownership_value_invalid
+        end
+
+        it "returns false if mortgage, grant and deposit total equals market value - discount" do
+          record.mortgage = 10_000
+          expect(record).not_to be_discounted_ownership_value_invalid
+        end
+      end
+    end
+
+    context "when mortgage is not routed to" do
+      let(:record) { FactoryBot.build(:sales_log, mortgageused: 2, deposit: 5_000, grant: 3_000, value: 20_000, discount: 10, ownershipsch: 2, saledate: Time.zone.local(2023, 4, 3)) }
+
+      it "returns true if grant and deposit total does not equal market value - discount" do
+        expect(record).to be_discounted_ownership_value_invalid
+      end
+
+      it "returns false if mortgage, grant and deposit total equals market value - discount" do
+        record.grant = 13_000
+        expect(record).not_to be_discounted_ownership_value_invalid
+      end
+    end
+
+    context "when ownership is not discounted" do
+      let(:record) { FactoryBot.build(:sales_log, mortgage: 10_000, deposit: 5_000, grant: 3_000, value: 20_000, discount: 10, ownershipsch: 1, saledate: Time.zone.local(2023, 4, 3)) }
+
+      it "returns false" do
+        expect(record).not_to be_discounted_ownership_value_invalid
+      end
+    end
+  end
 end