diff --git a/app/controllers/waste_carriers_engine/business_type_forms_controller.rb b/app/controllers/waste_carriers_engine/business_type_forms_controller.rb
index 77cd0b9f8..b3a419d37 100644
--- a/app/controllers/waste_carriers_engine/business_type_forms_controller.rb
+++ b/app/controllers/waste_carriers_engine/business_type_forms_controller.rb
@@ -13,7 +13,7 @@ def create
     private
 
     def transient_registration_attributes
-      params.require(:business_type_form).permit(:business_type, :reg_identifier)
+      params.fetch(:business_type_form, {}).permit(:business_type, :reg_identifier)
     end
   end
 end
diff --git a/app/controllers/waste_carriers_engine/cards_forms_controller.rb b/app/controllers/waste_carriers_engine/cards_forms_controller.rb
index fb0723895..a2b4e3e70 100644
--- a/app/controllers/waste_carriers_engine/cards_forms_controller.rb
+++ b/app/controllers/waste_carriers_engine/cards_forms_controller.rb
@@ -13,7 +13,7 @@ def create
     private
 
     def transient_registration_attributes
-      params.require(:cards_form).permit(:temp_cards)
+      params.fetch(:cards_form, {}).permit(:temp_cards)
     end
   end
 end
diff --git a/app/controllers/waste_carriers_engine/cbd_type_forms_controller.rb b/app/controllers/waste_carriers_engine/cbd_type_forms_controller.rb
index 0a785d917..958d5a3c7 100644
--- a/app/controllers/waste_carriers_engine/cbd_type_forms_controller.rb
+++ b/app/controllers/waste_carriers_engine/cbd_type_forms_controller.rb
@@ -13,7 +13,7 @@ def create
     private
 
     def transient_registration_attributes
-      params.require(:cbd_type_form).permit(:registration_type)
+      params.fetch(:cbd_type_form, {}).permit(:registration_type)
     end
   end
 end
diff --git a/app/controllers/waste_carriers_engine/company_name_forms_controller.rb b/app/controllers/waste_carriers_engine/company_name_forms_controller.rb
index 44d5ef5b4..68ec018e0 100644
--- a/app/controllers/waste_carriers_engine/company_name_forms_controller.rb
+++ b/app/controllers/waste_carriers_engine/company_name_forms_controller.rb
@@ -13,7 +13,7 @@ def create
     private
 
     def transient_registration_attributes
-      params.require(:company_name_form).permit(:company_name)
+      params.fetch(:company_name_form, {}).permit(:company_name)
     end
   end
 end
diff --git a/app/controllers/waste_carriers_engine/company_postcode_forms_controller.rb b/app/controllers/waste_carriers_engine/company_postcode_forms_controller.rb
index 903cf372f..5d8e15b4c 100644
--- a/app/controllers/waste_carriers_engine/company_postcode_forms_controller.rb
+++ b/app/controllers/waste_carriers_engine/company_postcode_forms_controller.rb
@@ -13,7 +13,7 @@ def create
     private
 
     def transient_registration_attributes
-      params.require(:company_postcode_form).permit(:temp_company_postcode)
+      params.fetch(:company_postcode_form, {}).permit(:temp_company_postcode)
     end
   end
 end
diff --git a/app/controllers/waste_carriers_engine/construction_demolition_forms_controller.rb b/app/controllers/waste_carriers_engine/construction_demolition_forms_controller.rb
index bbc9a7d97..d678e0304 100644
--- a/app/controllers/waste_carriers_engine/construction_demolition_forms_controller.rb
+++ b/app/controllers/waste_carriers_engine/construction_demolition_forms_controller.rb
@@ -13,7 +13,7 @@ def create
     private
 
     def transient_registration_attributes
-      params.require(:construction_demolition_form).permit(:construction_waste)
+      params.fetch(:construction_demolition_form, {}).permit(:construction_waste)
     end
   end
 end
diff --git a/app/controllers/waste_carriers_engine/contact_email_forms_controller.rb b/app/controllers/waste_carriers_engine/contact_email_forms_controller.rb
index 5e54080d6..e2ebcaa74 100644
--- a/app/controllers/waste_carriers_engine/contact_email_forms_controller.rb
+++ b/app/controllers/waste_carriers_engine/contact_email_forms_controller.rb
@@ -13,7 +13,7 @@ def create
     private
 
     def transient_registration_attributes
-      params.require(:contact_email_form).permit(:contact_email, :confirmed_email)
+      params.fetch(:contact_email_form, {}).permit(:contact_email, :confirmed_email)
     end
   end
 end
diff --git a/app/controllers/waste_carriers_engine/contact_name_forms_controller.rb b/app/controllers/waste_carriers_engine/contact_name_forms_controller.rb
index a8c4df172..5826d8191 100644
--- a/app/controllers/waste_carriers_engine/contact_name_forms_controller.rb
+++ b/app/controllers/waste_carriers_engine/contact_name_forms_controller.rb
@@ -13,7 +13,7 @@ def create
     private
 
     def transient_registration_attributes
-      params.require(:contact_name_form).permit(:first_name, :last_name)
+      params.fetch(:contact_name_form, {}).permit(:first_name, :last_name)
     end
   end
 end
diff --git a/app/controllers/waste_carriers_engine/contact_phone_forms_controller.rb b/app/controllers/waste_carriers_engine/contact_phone_forms_controller.rb
index 25c4c6c00..b973194c5 100644
--- a/app/controllers/waste_carriers_engine/contact_phone_forms_controller.rb
+++ b/app/controllers/waste_carriers_engine/contact_phone_forms_controller.rb
@@ -13,7 +13,7 @@ def create
     private
 
     def transient_registration_attributes
-      params.require(:contact_phone_form).permit(:phone_number)
+      params.fetch(:contact_phone_form, {}).permit(:phone_number)
     end
   end
 end
diff --git a/app/controllers/waste_carriers_engine/contact_postcode_forms_controller.rb b/app/controllers/waste_carriers_engine/contact_postcode_forms_controller.rb
index 1a6e7a387..a84833910 100644
--- a/app/controllers/waste_carriers_engine/contact_postcode_forms_controller.rb
+++ b/app/controllers/waste_carriers_engine/contact_postcode_forms_controller.rb
@@ -13,7 +13,7 @@ def create
     private
 
     def transient_registration_attributes
-      params.require(:contact_postcode_form).permit(:temp_contact_postcode)
+      params.fetch(:contact_postcode_form, {}).permit(:temp_contact_postcode)
     end
   end
 end
diff --git a/app/controllers/waste_carriers_engine/declaration_forms_controller.rb b/app/controllers/waste_carriers_engine/declaration_forms_controller.rb
index c7b2c7207..63bc196bb 100644
--- a/app/controllers/waste_carriers_engine/declaration_forms_controller.rb
+++ b/app/controllers/waste_carriers_engine/declaration_forms_controller.rb
@@ -16,7 +16,7 @@ def create
     private
 
     def transient_registration_attributes
-      params.require(:declaration_form).permit(:declaration)
+      params.fetch(:declaration_form, {}).permit(:declaration)
     end
   end
 end
diff --git a/app/controllers/waste_carriers_engine/declare_convictions_forms_controller.rb b/app/controllers/waste_carriers_engine/declare_convictions_forms_controller.rb
index 8a90658ea..267099adf 100644
--- a/app/controllers/waste_carriers_engine/declare_convictions_forms_controller.rb
+++ b/app/controllers/waste_carriers_engine/declare_convictions_forms_controller.rb
@@ -13,7 +13,7 @@ def create
     private
 
     def transient_registration_attributes
-      params.require(:declare_convictions_form).permit(:declared_convictions)
+      params.fetch(:declare_convictions_form, {}).permit(:declared_convictions)
     end
   end
 end
diff --git a/app/controllers/waste_carriers_engine/location_forms_controller.rb b/app/controllers/waste_carriers_engine/location_forms_controller.rb
index 7b6c6c509..dcdc76be5 100644
--- a/app/controllers/waste_carriers_engine/location_forms_controller.rb
+++ b/app/controllers/waste_carriers_engine/location_forms_controller.rb
@@ -13,7 +13,7 @@ def create
     private
 
     def transient_registration_attributes
-      params.require(:location_form).permit(:location)
+      params.fetch(:location_form, {}).permit(:location)
     end
   end
 end
diff --git a/app/controllers/waste_carriers_engine/other_businesses_forms_controller.rb b/app/controllers/waste_carriers_engine/other_businesses_forms_controller.rb
index 0e0471438..17543a045 100644
--- a/app/controllers/waste_carriers_engine/other_businesses_forms_controller.rb
+++ b/app/controllers/waste_carriers_engine/other_businesses_forms_controller.rb
@@ -13,7 +13,7 @@ def create
     private
 
     def transient_registration_attributes
-      params.require(:other_businesses_form).permit(:other_businesses)
+      params.fetch(:other_businesses_form, {}).permit(:other_businesses)
     end
   end
 end
diff --git a/app/controllers/waste_carriers_engine/registration_number_forms_controller.rb b/app/controllers/waste_carriers_engine/registration_number_forms_controller.rb
index 6f63b699e..3e91c5b33 100644
--- a/app/controllers/waste_carriers_engine/registration_number_forms_controller.rb
+++ b/app/controllers/waste_carriers_engine/registration_number_forms_controller.rb
@@ -13,7 +13,7 @@ def create
     private
 
     def transient_registration_attributes
-      params.require(:registration_number_form).permit(:company_no)
+      params.fetch(:registration_number_form, {}).permit(:company_no)
     end
   end
 end
diff --git a/app/controllers/waste_carriers_engine/service_provided_forms_controller.rb b/app/controllers/waste_carriers_engine/service_provided_forms_controller.rb
index 9281152c3..f2672805f 100644
--- a/app/controllers/waste_carriers_engine/service_provided_forms_controller.rb
+++ b/app/controllers/waste_carriers_engine/service_provided_forms_controller.rb
@@ -13,7 +13,7 @@ def create
     private
 
     def transient_registration_attributes
-      params.require(:service_provided_form).permit(:is_main_service)
+      params.fetch(:service_provided_form, {}).permit(:is_main_service)
     end
   end
 end
diff --git a/spec/support/shared_examples/request_post_form.rb b/spec/support/shared_examples/post_form.rb
similarity index 95%
rename from spec/support/shared_examples/request_post_form.rb
rename to spec/support/shared_examples/post_form.rb
index 57317f421..21444af72 100644
--- a/spec/support/shared_examples/request_post_form.rb
+++ b/spec/support/shared_examples/post_form.rb
@@ -94,6 +94,16 @@
           end
         end
 
+        context "when the params are empty" do
+          it "does not throw an error" do
+            # rubocop:disable Style/BlockDelimiters
+            expect {
+              post_with_params(form, reg_identifier: transient_registration.reg_identifier)
+            }.not_to raise_error
+            # rubocop:enable Style/BlockDelimiters
+          end
+        end
+
         context "when the reg_identifier is invalid" do
           before do
             valid_params[:reg_identifier] = "foo"