diff --git a/app/models/validations/sales/sale_information_validations.rb b/app/models/validations/sales/sale_information_validations.rb
index 11049e8ff..bdbecd3cf 100644
--- a/app/models/validations/sales/sale_information_validations.rb
+++ b/app/models/validations/sales/sale_information_validations.rb
@@ -7,11 +7,24 @@ module Validations::Sales::SaleInformationValidations
     end
   end
 
-  def validate_pratical_completion_date_before_saledate(record)
+  def validate_practical_completion_date_before_saledate(record)
     return if record.saledate.blank? || record.hodate.blank?
 
     unless record.saledate > record.hodate
       record.errors.add :hodate, "Practical completion or handover date must be before exchange date"
     end
   end
+
+  def validate_years_living_in_property_before_purchase(record)
+    return unless record.proplen && record.proplen.nonzero?
+
+    case record.type
+    when 18
+      record.errors.add :type, "Social HomeBuy buyers should not have lived here before"
+      record.errors.add :proplen, "Social HomeBuy or Rent to Buy buyers should not have lived here before"
+    when 28, 29
+      record.errors.add :type, "Rent to Buy buyers should not have lived here before"
+      record.errors.add :proplen, "Rent to Buy buyers should not have lived here before"
+    end
+  end
 end
diff --git a/spec/models/validations/sales/sale_information_validations_spec.rb b/spec/models/validations/sales/sale_information_validations_spec.rb
index a808d2ba8..848b7c52d 100644
--- a/spec/models/validations/sales/sale_information_validations_spec.rb
+++ b/spec/models/validations/sales/sale_information_validations_spec.rb
@@ -47,12 +47,12 @@ RSpec.describe Validations::Sales::SaleInformationValidations do
     end
   end
 
-  describe "#validate_pratical_completion_date_before_saledate" do
+  describe "#validate_practical_completion_date_before_saledate" do
     context "when hodate blank" do
       let(:record) { build(:sales_log, hodate: nil) }
 
       it "does not add an error" do
-        sale_information_validator.validate_pratical_completion_date_before_saledate(record)
+        sale_information_validator.validate_practical_completion_date_before_saledate(record)
 
         expect(record.errors).not_to be_present
       end
@@ -62,7 +62,7 @@ RSpec.describe Validations::Sales::SaleInformationValidations do
       let(:record) { build(:sales_log, saledate: nil) }
 
       it "does not add an error" do
-        sale_information_validator.validate_pratical_completion_date_before_saledate(record)
+        sale_information_validator.validate_practical_completion_date_before_saledate(record)
 
         expect(record.errors).not_to be_present
       end
@@ -72,7 +72,7 @@ RSpec.describe Validations::Sales::SaleInformationValidations do
       let(:record) { build(:sales_log, hodate: nil, saledate: nil) }
 
       it "does not add an error" do
-        sale_information_validator.validate_pratical_completion_date_before_saledate(record)
+        sale_information_validator.validate_practical_completion_date_before_saledate(record)
 
         expect(record.errors).not_to be_present
       end
@@ -82,7 +82,7 @@ RSpec.describe Validations::Sales::SaleInformationValidations do
       let(:record) { build(:sales_log, hodate: 2.months.ago, saledate: 1.month.ago) }
 
       it "does not add the error" do
-        sale_information_validator.validate_pratical_completion_date_before_saledate(record)
+        sale_information_validator.validate_practical_completion_date_before_saledate(record)
 
         expect(record.errors).not_to be_present
       end
@@ -92,7 +92,7 @@ RSpec.describe Validations::Sales::SaleInformationValidations do
       let(:record) { build(:sales_log, hodate: 1.month.ago, saledate: 2.months.ago) }
 
       it "adds error" do
-        sale_information_validator.validate_pratical_completion_date_before_saledate(record)
+        sale_information_validator.validate_practical_completion_date_before_saledate(record)
 
         expect(record.errors[:hodate]).to be_present
       end
@@ -102,10 +102,63 @@ RSpec.describe Validations::Sales::SaleInformationValidations do
       let(:record) { build(:sales_log, hodate: Time.zone.parse("2023-07-01"), saledate: Time.zone.parse("2023-07-01")) }
 
       it "does not add an error" do
-        sale_information_validator.validate_pratical_completion_date_before_saledate(record)
+        sale_information_validator.validate_practical_completion_date_before_saledate(record)
 
         expect(record.errors[:hodate]).to be_present
       end
     end
   end
+
+  describe "#validate_years_living_in_property_before_purchase" do
+    context "when proplen blank" do
+      let(:record) { build(:sales_log, proplen: nil) }
+
+      it "does not add an error" do
+        sale_information_validator.validate_years_living_in_property_before_purchase(record)
+
+        expect(record.errors).not_to be_present
+      end
+    end
+
+    context "when type blank" do
+      let(:record) { build(:sales_log, type: nil) }
+
+      it "does not add an error" do
+        sale_information_validator.validate_years_living_in_property_before_purchase(record)
+
+        expect(record.errors).not_to be_present
+      end
+    end
+
+    context "when proplen 0" do
+      let(:record) { build(:sales_log, proplen: 0) }
+
+      it "does not add an error" do
+        sale_information_validator.validate_years_living_in_property_before_purchase(record)
+
+        expect(record.errors).not_to be_present
+      end
+    end
+
+    context "when type Rent to Buy and proplen > 0" do
+      let(:record) { build(:sales_log, proplen: 1, type: 28) }
+
+      it "adds an error" do
+        sale_information_validator.validate_years_living_in_property_before_purchase(record)
+
+        expect(record.errors).to be_present
+      end
+    end
+
+    context "when type Social HomeBuy and proplen > 0" do
+      let(:record) { build(:sales_log, proplen: 1, type: 18) }
+
+      it "adds an error" do
+        sale_information_validator.validate_years_living_in_property_before_purchase(record)
+
+        expect(record.errors).to be_present
+      end
+    end
+
+  end
 end