diff --git a/app/models/validations/household_validations.rb b/app/models/validations/household_validations.rb
index 41ece6c69..bfd025b35 100644
--- a/app/models/validations/household_validations.rb
+++ b/app/models/validations/household_validations.rb
@@ -73,6 +73,12 @@ module Validations::HouseholdValidations
     end
   end
 
+  def validate_referral(record)
+    if record.tenancy == "Secure (including flexible)" && record.referral == "Internal transfer"
+      record.errors.add :referral, I18n.t("validations.household.referral.secure_tenancy")
+    end
+  end
+
 private
 
   def women_of_child_bearing_age_in_household(record)
diff --git a/app/models/validations/tenancy_validations.rb b/app/models/validations/tenancy_validations.rb
index f45bd0cd9..43b96c8a9 100644
--- a/app/models/validations/tenancy_validations.rb
+++ b/app/models/validations/tenancy_validations.rb
@@ -25,4 +25,10 @@ module Validations::TenancyValidations
   def validate_other_tenancy_type(record)
     validate_other_field(record, :tenancy, :tenancyother)
   end
+
+  def validate_tenancy(record)
+    if record.tenancy == "Secure (including flexible)" && record.referral == "Internal transfer"
+      record.errors.add :tenancy, I18n.t("validations.tenancy.internal_referral")
+    end
+  end
 end
diff --git a/config/locales/en.yml b/config/locales/en.yml
index a0aad8e60..c69ee8724 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -110,12 +110,15 @@ en:
         one_or_two_choices: "Only one box must be ticked or 'other disabilities' plus one of mobility disabilities"
       prevten:
         non_temp_accommodation: "Answer cannot be non-temporary accommodation as you already told us this is a re-let to tenant who occupied the same property as temporary accommodation"
+      referral:
+        secure_tenancy: "Answer must be internal transfer as you already told us this is a secure tenancy"
 
     tenancy:
       length:
         fixed_term_not_required: "You must only answer the fixed term tenancy length question if the tenancy type is fixed term"
         shorthold: "Fixed term – Assured Shorthold Tenancy (AST) should be between 2 and 99 years"
         secure: "Secure (including flexible) should be between 2 and 99 years or not specified"
+      internal_referral: "Answer must be secure tenancy as you already told us this tenancy is an internal transfer"
 
     local_authority:
       referral:
diff --git a/spec/models/validations/household_validations_spec.rb b/spec/models/validations/household_validations_spec.rb
index 95edc1313..0c01b3fe7 100644
--- a/spec/models/validations/household_validations_spec.rb
+++ b/spec/models/validations/household_validations_spec.rb
@@ -477,4 +477,16 @@ RSpec.describe Validations::HouseholdValidations do
       expect(record.errors["accessibility_requirements"]).to be_empty
     end
   end
+
+  describe "referral validations" do
+    context "when type of tenancy is secure" do
+      it "must be internal transfer" do
+        record.tenancy = "Secure (including flexible)"
+        record.referral = "Internal transfer"
+        household_validator.validate_referral(record)
+        expect(record.errors["referral"])
+          .to include(match I18n.t("validations.household.referral.secure_tenancy"))
+      end
+    end
+  end
 end
diff --git a/spec/models/validations/tenancy_validations_spec.rb b/spec/models/validations/tenancy_validations_spec.rb
index 4910ce05d..762ac7278 100644
--- a/spec/models/validations/tenancy_validations_spec.rb
+++ b/spec/models/validations/tenancy_validations_spec.rb
@@ -106,6 +106,16 @@ RSpec.describe Validations::TenancyValidations do
             expect(record.errors["tenancy"]).to be_empty
           end
         end
+
+        context "when referral is internal transfer" do
+          it "adds an error" do
+            record.tenancy = "Secure (including flexible)"
+            record.referral = "Internal transfer"
+            tenancy_validator.validate_tenancy(record)
+            expect(record.errors["tenancy"])
+              .to include(match I18n.t("validations.tenancy.internal_referral"))
+          end
+        end
       end
     end
   end