diff --git a/.review_apps/ecs_task_definition.tf b/.review_apps/ecs_task_definition.tf
index b019cea45..f8c6b8e97 100644
--- a/.review_apps/ecs_task_definition.tf
+++ b/.review_apps/ecs_task_definition.tf
@@ -46,7 +46,7 @@ locals {
     { name = "SETTINGS__FORMS_ENV", value = "review" },
     { name = "SETTINGS__FORMS_RUNNER__URL", value = "https://${local.runner_review_app_hostname}" },
     { name = "ALLOWED_HOST_PATTERNS", value = "localhost:3000" },
-    { name = "SETTINGS__FEATURES__JSON_SUBMISSION_ENABLED", value = "true" }
+    { name = "SETTINGS__FEATURES__DESCRIBE_NONE_OF_THE_ABOVE_ENABLED", value = "true" }
   ]
 }
 
diff --git a/app/components/question/selection_component/view.html.erb b/app/components/question/selection_component/view.html.erb
index fbc420655..ea725b9e2 100644
--- a/app/components/question/selection_component/view.html.erb
+++ b/app/components/question/selection_component/view.html.erb
@@ -1,4 +1,4 @@
-<% if question.answer_settings.selection_options.count > 30 %>
+<% if question.autocomplete_component? %>
   <%= render DfE::Autocomplete::View.new(
     form_builder,
     attribute_name: :selection,
diff --git a/app/components/question/selection_component/view.rb b/app/components/question/selection_component/view.rb
index e813bfb4d..eb25a543a 100644
--- a/app/components/question/selection_component/view.rb
+++ b/app/components/question/selection_component/view.rb
@@ -36,17 +36,37 @@ def divider
       def none_of_the_above_radio_button
         return nil unless question.is_optional?
 
-        option = form_builder.govuk_radio_button :selection, I18n.t("page.none_of_the_above"), label: { text: I18n.t("page.none_of_the_above") }
+        option = form_builder.govuk_radio_button :selection,
+                                                 I18n.t("page.none_of_the_above"),
+                                                 label: { text: I18n.t("page.none_of_the_above") },
+                                                 &method(:none_of_the_above_question_field)
         safe_join([divider, option])
       end
 
       def none_of_the_above_checkbox
         return nil unless question.is_optional?
 
-        option = form_builder.govuk_check_box :selection, I18n.t("page.none_of_the_above"), exclusive: true, label: { text: I18n.t("page.none_of_the_above") }
+        option = form_builder.govuk_check_box :selection,
+                                              I18n.t("page.none_of_the_above"),
+                                              exclusive: true,
+                                              label: { text: I18n.t("page.none_of_the_above") },
+                                              &method(:none_of_the_above_question_field)
         safe_join([divider, option])
       end
 
+      def none_of_the_above_question_field
+        if question.has_none_of_the_above_question?
+          form_builder.govuk_text_field :none_of_the_above_answer, label: { text: none_of_the_above_question_text }, width: "three-quarters"
+        end
+      end
+
+      def none_of_the_above_question_text
+        none_of_the_above_question = question.answer_settings.none_of_the_above_question
+        return none_of_the_above_question.question_text if none_of_the_above_question.is_optional != "true"
+
+        "#{none_of_the_above_question.question_text} #{I18n.t('page.optional')}"
+      end
+
       def radio_button_options
         question.answer_settings.selection_options.map.with_index do |option, index|
           form_builder.govuk_radio_button :selection, option.name, label: { text: option.name }, link_errors: index.zero?
diff --git a/app/models/question/selection.rb b/app/models/question/selection.rb
index e592c1861..891735a7c 100644
--- a/app/models/question/selection.rb
+++ b/app/models/question/selection.rb
@@ -1,9 +1,18 @@
 module Question
   class Selection < QuestionBase
     attribute :selection
+    attribute :none_of_the_above_answer
+
+    before_validation :clear_none_of_the_above_answer_if_not_selected
+
     validates :selection, presence: true
     validate :selection, :validate_checkbox, if: :allow_multiple_answers?
     validate :selection, :validate_radio, unless: :allow_multiple_answers?
+    validates :none_of_the_above_answer, length: { maximum: 499 }
+
+    with_options unless: :autocomplete_component? do
+      validates :none_of_the_above_answer, presence: true, if: :validate_none_of_the_above_answer_presence?
+    end
 
     def allow_multiple_answers?
       answer_settings.only_one_option != "true"
@@ -42,8 +51,20 @@ def selection_options_with_none_of_the_above
       [*options, none_of_the_above_option]
     end
 
+    def autocomplete_component?
+      answer_settings.selection_options.count > 30
+    end
+
+    def has_none_of_the_above_question?
+      none_of_the_above_question.present?
+    end
+
   private
 
+    def clear_none_of_the_above_answer_if_not_selected
+      self.none_of_the_above_answer = nil unless none_of_the_above_selected?
+    end
+
     def allowed_options
       selection_options_with_none_of_the_above.map(&:name)
     end
@@ -68,5 +89,23 @@ def validate_checkbox
 
       errors.add(:selection, :inclusion) if selection_without_blanks.any? { |item| allowed_options.exclude?(item) }
     end
+
+    def validate_none_of_the_above_answer_presence?
+      none_of_the_above_question.present? && none_of_the_above_question.is_optional != "true" && none_of_the_above_selected?
+    end
+
+    def none_of_the_above_question
+      return nil unless is_optional?
+      return nil unless answer_settings.respond_to?(:none_of_the_above_question)
+      return nil unless answer_settings.none_of_the_above_question.respond_to?(:question_text)
+
+      answer_settings.none_of_the_above_question
+    end
+
+    def none_of_the_above_selected?
+      return selection_without_blanks.include?(I18n.t("page.none_of_the_above")) if allow_multiple_answers?
+
+      selection == I18n.t("page.none_of_the_above")
+    end
   end
 end
diff --git a/config/locales/cy.yml b/config/locales/cy.yml
index dffcc8121..99b0c3be4 100644
--- a/config/locales/cy.yml
+++ b/config/locales/cy.yml
@@ -174,6 +174,9 @@ cy:
               phone_too_short: Dylai’r rhif ffôn fod ag 8 neu fwy o ddigidau
         question/selection:
           attributes:
+            none_of_the_above_answer:
+              blank: Rhowch ateb
+              too_long: Rhaid i’r ateb fod yn llai na 500 o gymeriadau
             selection:
               blank: Dewiswch un opsiwn
               both_none_and_value_selected: Dewiswch un neu ragor o opsiynau neu dewiswch 'Dim un o’r uchod'
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 1be1e2b77..e43cc77e9 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -174,6 +174,9 @@ en:
               phone_too_short: The phone number should have 8 digits or more
         question/selection:
           attributes:
+            none_of_the_above_answer:
+              blank: Enter an answer
+              too_long: The answer must be shorter than 500 characters
             selection:
               blank: Select one option
               both_none_and_value_selected: Select one or more options, or select ‘None of the above’
diff --git a/spec/components/question/selection_component/view_spec.rb b/spec/components/question/selection_component/view_spec.rb
index c0610d572..c6a48a043 100644
--- a/spec/components/question/selection_component/view_spec.rb
+++ b/spec/components/question/selection_component/view_spec.rb
@@ -14,6 +14,42 @@
     render_inline(described_class.new(form_builder:, question:, extra_question_text_suffix:))
   end
 
+  shared_examples "None of the above question field" do
+    context "when a 'None of the above' question is not defined" do
+      it "does not render a conditional text field for the 'None of the above' option" do
+        expect(page).not_to have_css("input[type='text'][name='form[none_of_the_above_answer]']")
+      end
+    end
+
+    context "when a 'None of the above' question is defined" do
+      let(:none_of_the_above_question_is_optional) { "true" }
+      let(:question) do
+        build(:single_selection_question,
+              :with_none_of_the_above_question,
+              none_of_the_above_question_text: "Enter another answer",
+              none_of_the_above_question_is_optional:)
+      end
+
+      it "renders a conditional text field for the 'None of the above' option" do
+        expect(page).to have_css("input[type='text'][name='form[none_of_the_above_answer]']")
+      end
+
+      context "when the 'None of the above' question is optional" do
+        it "has the question text with an optional suffix as the label for the field" do
+          expect(page).to have_css("label[for='form-none-of-the-above-answer-field']", text: "Enter another answer (optional)")
+        end
+      end
+
+      context "when the 'None of the above' question is mandatory" do
+        let(:none_of_the_above_question_is_optional) { "false" }
+
+        it "has the question text as the label for the field" do
+          expect(page).to have_css("label[for='form-none-of-the-above-answer-field']", text: "Enter another answer")
+        end
+      end
+    end
+  end
+
   describe "when component is select one from a list field" do
     context "when there are 30 or fewer options" do
       let(:question) { build :single_selection_question, is_optional:, selection_options: }
@@ -70,6 +106,8 @@
         it "contains the 'None of the above' option" do
           expect(page).to have_css("input[type='radio'] + label", text: "None of the above")
         end
+
+        include_examples "None of the above question field"
       end
 
       context "when question has guidance" do
@@ -197,6 +235,8 @@
       it "contains the 'None of the above' option" do
         expect(page).to have_css("input[type='checkbox'] + label", text: "None of the above")
       end
+
+      include_examples "None of the above question field"
     end
 
     context "when question has guidance" do
diff --git a/spec/factories/models/question/selection.rb b/spec/factories/models/question/selection.rb
index 638febba6..b174b947b 100644
--- a/spec/factories/models/question/selection.rb
+++ b/spec/factories/models/question/selection.rb
@@ -3,6 +3,20 @@
     question_text { Faker::Lorem.question }
     hint_text { nil }
     is_optional { false }
+    answer_settings do
+      if none_of_the_above_question
+        Struct.new(:only_one_option, :selection_options, :none_of_the_above_question)
+              .new(only_one_option, selection_options, none_of_the_above_question)
+      else
+        Struct.new(:only_one_option, :selection_options).new(only_one_option, selection_options)
+      end
+    end
+
+    transient do
+      only_one_option { "true" }
+      selection_options { [DataStruct.new(name: "Option 1"), DataStruct.new(name: "Option 2")] }
+      none_of_the_above_question { nil }
+    end
 
     trait :with_hints do
       hint_text { Faker::Quote.yoda }
@@ -13,18 +27,24 @@
       guidance_markdown { "## List of items \n\n\n #{Faker::Markdown.ordered_list}" }
     end
 
-    factory :single_selection_question do
+    trait :with_none_of_the_above_question do
       transient do
-        selection_options { [DataStruct.new(name: "Option 1"),  DataStruct.new(name: "Option 2")] }
+        none_of_the_above_question_text { Faker::Lorem.question }
+        none_of_the_above_question_is_optional { "false" }
+      end
+      is_optional { true }
+      none_of_the_above_question do
+        Struct.new(:question_text, :is_optional)
+              .new(none_of_the_above_question_text, none_of_the_above_question_is_optional)
       end
-      answer_settings { DataStruct.new(only_one_option: "true", selection_options:) }
+    end
+
+    factory :single_selection_question do
+      only_one_option { "true" }
     end
 
     factory :multiple_selection_question do
-      transient do
-        selection_options { [DataStruct.new(name: "Option 1"),  DataStruct.new(name: "Option 2")] }
-      end
-      answer_settings { DataStruct.new(only_one_option: "false", selection_options:) }
+      only_one_option { "false" }
       selection { ["Option 1", "Option 2"] }
     end
   end
diff --git a/spec/models/question/selection_spec.rb b/spec/models/question/selection_spec.rb
index 581d550ab..d82a260ea 100644
--- a/spec/models/question/selection_spec.rb
+++ b/spec/models/question/selection_spec.rb
@@ -1,18 +1,11 @@
 require "rails_helper"
 
 RSpec.describe Question::Selection, type: :model do
-  subject(:question) { described_class.new({}, options) }
-
-  let(:options) do
-    {
-      is_optional:,
-      answer_settings: OpenStruct.new({
-        only_one_option:,
-        selection_options: [OpenStruct.new({ name: "option 1" }), OpenStruct.new({ name: "option 2" })],
-      }),
-      question_text:,
-    }
-  end
+  subject(:question) { build :selection, only_one_option:, selection_options:, is_optional:, question_text: }
+
+  let(:selection_options) { [OpenStruct.new({ name: "option 1" }), OpenStruct.new({ name: "option 2" })] }
+  let(:is_optional) { false }
+  let(:only_one_option) { "false" }
   let(:question_text) { Faker::Lorem.question }
 
   context "when the selection question is a checkbox" do
@@ -21,7 +14,7 @@
 
     it_behaves_like "a question model"
 
-    context "when created without attriibutes" do
+    context "when created without attributes" do
       it "returns invalid" do
         expect(question).not_to be_valid
         expect(question.errors[:selection]).to include(I18n.t("activemodel.errors.models.question/selection.attributes.selection.checkbox_blank"))
@@ -307,6 +300,134 @@
     end
   end
 
+  context "when there is a none of the above question configured" do
+    subject(:question) do
+      build(:selection, :with_none_of_the_above_question, only_one_option:, selection_options:, is_optional:,
+                                                          none_of_the_above_question_is_optional:)
+    end
+
+    let(:is_optional) { true }
+    let(:none_of_the_above_question_is_optional) { "true" }
+
+    context "when there fewer than 31 selection options" do
+      context "when only_one_option is false" do
+        let(:only_one_option) { "false" }
+
+        context "when none_of_the_above_question is optional" do
+          context "when 'None of the above' is selected" do
+            before do
+              question.selection = [I18n.t("page.none_of_the_above")]
+            end
+
+            it "is valid when there is no none_of_the_above_answer" do
+              expect(question).to be_valid
+              expect(question.errors[:none_of_the_above_answer]).to be_empty
+            end
+
+            it "is invalid when the none_of_the_above answer is too long" do
+              question.none_of_the_above_answer = "a" * 500
+              expect(question).not_to be_valid
+              expect(question.errors[:none_of_the_above_answer]).to include(I18n.t("activemodel.errors.models.question/selection.attributes.none_of_the_above_answer.too_long"))
+            end
+          end
+
+          context "when 'None of the above' is not selected" do
+            it "clears the none_of_the_above_answer before validating" do
+              question.selection = ["option 1"]
+              question.none_of_the_above_answer = "Some answer"
+              expect(question).to be_valid
+              expect(question.none_of_the_above_answer).to be_nil
+            end
+          end
+        end
+
+        context "when none_of_the_above_question is mandatory" do
+          let(:none_of_the_above_question_is_optional) { "false" }
+
+          context "when 'None of the above' is selected" do
+            before do
+              question.selection = [I18n.t("page.none_of_the_above")]
+            end
+
+            it "is invalid when there is no none_of_the_above_answer" do
+              expect(question).not_to be_valid
+              expect(question.errors[:none_of_the_above_answer]).to include(I18n.t("activemodel.errors.models.question/selection.attributes.none_of_the_above_answer.blank"))
+            end
+
+            it "is valid when there is a none_of_the_above_answer" do
+              question.none_of_the_above_answer = "Some answer"
+              expect(question).to be_valid
+              expect(question.errors[:none_of_the_above_answer]).to be_empty
+              expect(question.none_of_the_above_answer).to eq("Some answer")
+            end
+          end
+
+          context "when 'None of the above' is not selected" do
+            before do
+              question.selection = ["option 1"]
+            end
+
+            it "is valid when there is no none_of_the_above_answer" do
+              expect(question).to be_valid
+              expect(question.errors[:none_of_the_above_answer]).to be_empty
+            end
+
+            it "is valid when there is a none_of_the_above_answer that is too long" do
+              question.none_of_the_above_answer = "a" * 500
+              expect(question).to be_valid
+              expect(question.errors[:none_of_the_above_answer]).to be_empty
+            end
+
+            it "clears the none_of_the_above_answer before validating" do
+              question.none_of_the_above_answer = "Some answer"
+              expect(question).to be_valid
+              expect(question.none_of_the_above_answer).to be_nil
+            end
+          end
+        end
+      end
+
+      context "when only_one_option is true" do
+        let(:only_one_option) { "true" }
+        let(:none_of_the_above_question_is_optional) { "false" }
+
+        context "when 'None of the above' is selected" do
+          before do
+            question.selection = I18n.t("page.none_of_the_above")
+          end
+
+          it "is invalid when there is no none_of_the_above_answer" do
+            expect(question).not_to be_valid
+            expect(question.errors[:none_of_the_above_answer]).to include(I18n.t("activemodel.errors.models.question/selection.attributes.none_of_the_above_answer.blank"))
+          end
+
+          it "is invalid when the none_of_the_above answer is too long" do
+            question.none_of_the_above_answer = "a" * 500
+            expect(question).not_to be_valid
+            expect(question.errors[:none_of_the_above_answer]).to include(I18n.t("activemodel.errors.models.question/selection.attributes.none_of_the_above_answer.too_long"))
+          end
+        end
+
+        context "when 'None of the above' is not selected" do
+          before do
+            question.selection = "option 1"
+          end
+
+          it "is valid when there is no none_of_the_above_answer" do
+            expect(question).to be_valid
+            expect(question.errors[:none_of_the_above_answer]).to be_empty
+          end
+
+          it "is valid when there is a none_of_the_above_answer that is too long" do
+            question.none_of_the_above_answer = "a" * 500
+            expect(question).to be_valid
+            expect(question.errors[:none_of_the_above_answer]).to be_empty
+          end
+        end
+      end
+    end
+  end
+
   describe "#selection_options_with_none_of_the_above" do
     let(:only_one_option) { "true" }
     let(:none_of_the_above_option) { OpenStruct.new(name: I18n.t("page.none_of_the_above")) }
@@ -315,7 +436,7 @@
       let(:is_optional) { true }
 
       it "includes the selection options" do
-        question.answer_settings.each do |option|
+        question.answer_settings.selection_options.each do |option|
           expect(question.selection_options_with_none_of_the_above).to include(option)
         end
       end
@@ -339,4 +460,67 @@
       end
     end
   end
+
+  describe "#autocomplete_component?" do
+    context "when there are 30 selection options" do
+      let(:selection_options) { Array.new(30).map { |_index| OpenStruct.new(name: Faker::Lorem.sentence) } }
+
+      it "returns false" do
+        expect(question.autocomplete_component?).to be false
+      end
+    end
+
+    context "when there are more than 30 selection options" do
+      let(:selection_options) { Array.new(31).map { |_index| OpenStruct.new(name: Faker::Lorem.sentence) } }
+
+      it "returns true" do
+        expect(question.autocomplete_component?).to be true
+      end
+    end
+  end
+
+  describe "#has_none_of_the_above_question?" do
+    let(:is_optional) { true }
+
+    context "when there is a none of the above question configured" do
+      subject(:question) do
+        build(:selection, :with_none_of_the_above_question, only_one_option:, selection_options:, is_optional:,
+                                                            none_of_the_above_question_is_optional:)
+      end
+
+      let(:none_of_the_above_question_is_optional) { "true" }
+
+      it "returns true" do
+        expect(question.has_none_of_the_above_question?).to be true
+      end
+
+      context "when the question is not optional" do
+        let(:is_optional) { false }
+
+        it "returns false" do
+          expect(question.has_none_of_the_above_question?).to be false
+        end
+      end
+    end
+
+    context "when there is no none of the above question configured" do
+      it "returns false" do
+        expect(question.has_none_of_the_above_question?).to be false
+      end
+    end
+
+    context "when the none_of_the_above_question has no question_text" do
+      subject(:question) do
+        build(:selection,
+              is_optional:,
+              only_one_option:,
+              selection_options:,
+              none_of_the_above_question: Struct.new)
+      end
+
+      it "returns false" do
+        expect(question.has_none_of_the_above_question?).to be false
+      end
+    end
+  end
 end