diff --git a/app/models/sales_log.rb b/app/models/sales_log.rb
index 463381559..add706f7c 100644
--- a/app/models/sales_log.rb
+++ b/app/models/sales_log.rb
@@ -223,6 +223,10 @@ class SalesLog < Log
     type == 24
   end
 
+  def is_bedsit?
+    proptype == 2
+  end
+
   def shared_ownership_scheme?
     ownershipsch == 1
   end
diff --git a/app/models/validations/sales/property_validations.rb b/app/models/validations/sales/property_validations.rb
index 879e37ff1..83f86ec8f 100644
--- a/app/models/validations/sales/property_validations.rb
+++ b/app/models/validations/sales/property_validations.rb
@@ -7,4 +7,13 @@ module Validations::Sales::PropertyValidations
       record.errors.add :ppostcode_full, I18n.t("validations.property.postcode.must_match_previous")
     end
   end
+
+  def validate_bedsit_number_of_beds(record)
+    return unless record.proptype.present? && record.beds.present?
+
+    if record.is_bedsit? && record.beds > 1
+      record.errors.add :proptype, I18n.t("validations.property.proptype.bedsits_have_max_one_bedroom")
+      record.errors.add :beds, I18n.t("validations.property.beds.bedsits_have_max_one_bedroom")
+    end
+  end
 end
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 0a4ae34de..98e40dfb3 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -202,6 +202,9 @@ en:
       beds:
         non_positive: "Number of bedrooms has to be greater than 0"
         over_max: "Number of bedrooms cannot be more than 12"
+        bedsits_have_max_one_bedroom: "Number of bedrooms must be 1 if the property is a bedsit"
+      proptype:
+        bedsits_have_max_one_bedroom: "Answer cannot be 'Bedsit' if the property has 2 or more bedrooms"
       postcode:
         must_match_previous: "Buyer's last accommodation and discounted ownership postcodes must match"
 
diff --git a/spec/models/validations/sales/property_validations_spec.rb b/spec/models/validations/sales/property_validations_spec.rb
index fc3fdd1a8..180f16021 100644
--- a/spec/models/validations/sales/property_validations_spec.rb
+++ b/spec/models/validations/sales/property_validations_spec.rb
@@ -48,4 +48,40 @@ RSpec.describe Validations::Sales::PropertyValidations do
       end
     end
   end
+
+  describe "#validate_property_unit_type" do
+    context "when number of bedrooms is 1" do
+      let(:record) { FactoryBot.build(:sales_log, beds: 1, proptype: 2) }
+
+      it "does not add an error if it's a bedsit" do
+        property_validator.validate_bedsit_number_of_beds(record)
+        expect(record.errors).not_to be_present
+      end
+    end
+
+    context "when number of bedrooms is > 1" do
+      let(:record) { FactoryBot.build(:sales_log, beds: 2, proptype: 2) }
+
+      it "does add an error if it's a bedsit" do
+        property_validator.validate_bedsit_number_of_beds(record)
+        expect(record.errors.added?(:proptype, "Answer cannot be 'Bedsit' if the property has 2 or more bedrooms")).to be true
+        expect(record.errors.added?(:beds, "Number of bedrooms must be 1 if the property is a bedsit")).to be true
+      end
+
+      it "does not add an error if proptype is undefined" do
+        record.update!(proptype: nil)
+        property_validator.validate_bedsit_number_of_beds(record)
+        expect(record.errors).not_to be_present
+      end
+    end
+
+    context "when number of bedrooms is undefined" do
+      let(:record) { FactoryBot.build(:sales_log, beds: nil, proptype: 2) }
+
+      it "does not add an error if it's a bedsit" do
+        property_validator.validate_bedsit_number_of_beds(record)
+        expect(record.errors).not_to be_present
+      end
+    end
+  end
 end
diff --git a/spec/requests/sales_logs_controller_spec.rb b/spec/requests/sales_logs_controller_spec.rb
index 925e3f1f3..e45fee440 100644
--- a/spec/requests/sales_logs_controller_spec.rb
+++ b/spec/requests/sales_logs_controller_spec.rb
@@ -61,6 +61,31 @@ RSpec.describe SalesLogsController, type: :request do
           expect(response).to have_http_status(:unauthorized)
         end
       end
+
+      context "with a request containing invalid json parameters" do
+        let(:params) do
+          {
+            "saledate": Date.new(2022, 4, 1),
+            "purchid": "1",
+            "ownershipsch": 1,
+            "type": 2,
+            "jointpur": 1,
+            "jointmore": 1,
+            "beds": 2,
+            "proptype": 2,
+          }
+        end
+
+        before do
+          post "/sales-logs", headers:, params: params.to_json
+        end
+
+        it "validates sales log parameters" do
+          json_response = JSON.parse(response.body)
+          expect(response).to have_http_status(:unprocessable_entity)
+          expect(json_response["errors"]).to match_array([["beds", ["Number of bedrooms must be 1 if the property is a bedsit"]], ["proptype", ["Answer cannot be 'Bedsit' if the property has 2 or more bedrooms"]]])
+        end
+      end
     end
 
     context "when UI" do