diff --git a/app/models/form/lettings/pages/person_age.rb b/app/models/form/lettings/pages/person_age.rb
index 66f7d3d89..525341266 100644
--- a/app/models/form/lettings/pages/person_age.rb
+++ b/app/models/form/lettings/pages/person_age.rb
@@ -1,15 +1,21 @@
 class Form::Lettings::Pages::PersonAge < ::Form::Page
-  def initialize(id, hsh, subsection, person_index:)
+  def initialize(id, hsh, subsection, person_index:, is_child:)
     super(id, hsh, subsection)
-    @id = "person_#{person_index}_age"
-    @depends_on = [{ "details_known_#{person_index}" => 0 }]
+    @id = is_child ? "person_#{person_index}_age_child" : "person_#{person_index}_age_non_child"
     @person_index = person_index
+    @is_child = is_child
+    @depends_on = [
+      {
+        "details_known_#{person_index}" => 0,
+        "person_#{person_index}_child_relation?" => is_child,
+      },
+    ]
   end
 
   def questions
     @questions ||= [
       Form::Lettings::Questions::AgeKnown.new(nil, nil, self, person_index: @person_index),
-      Form::Lettings::Questions::Age.new(nil, nil, self, person_index: @person_index),
+      Form::Lettings::Questions::Age.new(nil, nil, self, person_index: @person_index, is_child: @is_child),
     ]
   end
 end
diff --git a/app/models/form/lettings/questions/age.rb b/app/models/form/lettings/questions/age.rb
index f160f1948..95fad10fa 100644
--- a/app/models/form/lettings/questions/age.rb
+++ b/app/models/form/lettings/questions/age.rb
@@ -1,5 +1,5 @@
 class Form::Lettings::Questions::Age < ::Form::Question
-  def initialize(id, hsh, page, person_index:)
+  def initialize(id, hsh, page, person_index:, is_child:)
     super(id, hsh, page)
     @id = "age#{person_index}"
     @check_answer_label = "Person #{person_index}’s age"
@@ -9,7 +9,8 @@ class Form::Lettings::Questions::Age < ::Form::Question
     @inferred_check_answers_value = [{ "condition" => { "age#{person_index}_known" => 1 }, "value" => "Not known" }]
     @check_answers_card_number = person_index
     @max = 120
-    @min = 0
+    @min = 1
     @step = 1
+    @hint_text = "For a child under 1, enter 1" if is_child
   end
 end
diff --git a/app/models/form/lettings/subsections/household_characteristics.rb b/app/models/form/lettings/subsections/household_characteristics.rb
index 8a5bdf8c1..0d9201f67 100644
--- a/app/models/form/lettings/subsections/household_characteristics.rb
+++ b/app/models/form/lettings/subsections/household_characteristics.rb
@@ -30,7 +30,8 @@ class Form::Lettings::Subsections::HouseholdCharacteristics < ::Form::Subsection
       Form::Lettings::Pages::LeadTenantOverRetirementValueCheck.new(nil, nil, self),
       Form::Lettings::Pages::PersonKnown.new(nil, nil, self, person_index: 2),
       Form::Lettings::Pages::PersonRelationshipToLead.new(nil, nil, self, person_index: 2),
-      Form::Lettings::Pages::PersonAge.new(nil, nil, self, person_index: 2),
+      Form::Lettings::Pages::PersonAge.new(nil, nil, self, person_index: 2, is_child: true),
+      Form::Lettings::Pages::PersonAge.new(nil, nil, self, person_index: 2, is_child: false),
       Form::Lettings::Pages::NoFemalesPregnantHouseholdPersonAgeValueCheck.new(nil, nil, self,
                                                                                person_index: 2),
       Form::Lettings::Pages::FemalesInSoftAgeRangeInPregnantHouseholdPersonAgeValueCheck.new(nil, nil, self,
@@ -44,7 +45,8 @@ class Form::Lettings::Subsections::HouseholdCharacteristics < ::Form::Subsection
       Form::Lettings::Pages::PersonOverRetirementValueCheck.new(nil, nil, self, person_index: 2),
       Form::Lettings::Pages::PersonKnown.new(nil, nil, self, person_index: 3),
       Form::Lettings::Pages::PersonRelationshipToLead.new(nil, nil, self, person_index: 3),
-      Form::Lettings::Pages::PersonAge.new(nil, nil, self, person_index: 3),
+      Form::Lettings::Pages::PersonAge.new(nil, nil, self, person_index: 3, is_child: true),
+      Form::Lettings::Pages::PersonAge.new(nil, nil, self, person_index: 3, is_child: false),
       Form::Lettings::Pages::NoFemalesPregnantHouseholdPersonAgeValueCheck.new(nil, nil, self,
                                                                                person_index: 3),
       Form::Lettings::Pages::FemalesInSoftAgeRangeInPregnantHouseholdPersonAgeValueCheck.new(nil, nil, self,
@@ -58,7 +60,8 @@ class Form::Lettings::Subsections::HouseholdCharacteristics < ::Form::Subsection
       Form::Lettings::Pages::PersonOverRetirementValueCheck.new(nil, nil, self, person_index: 3),
       Form::Lettings::Pages::PersonKnown.new(nil, nil, self, person_index: 4),
       Form::Lettings::Pages::PersonRelationshipToLead.new(nil, nil, self, person_index: 4),
-      Form::Lettings::Pages::PersonAge.new(nil, nil, self, person_index: 4),
+      Form::Lettings::Pages::PersonAge.new(nil, nil, self, person_index: 4, is_child: true),
+      Form::Lettings::Pages::PersonAge.new(nil, nil, self, person_index: 4, is_child: false),
       Form::Lettings::Pages::NoFemalesPregnantHouseholdPersonAgeValueCheck.new(nil, nil, self,
                                                                                person_index: 4),
       Form::Lettings::Pages::FemalesInSoftAgeRangeInPregnantHouseholdPersonAgeValueCheck.new(nil, nil, self,
@@ -72,7 +75,8 @@ class Form::Lettings::Subsections::HouseholdCharacteristics < ::Form::Subsection
       Form::Lettings::Pages::PersonOverRetirementValueCheck.new(nil, nil, self, person_index: 4),
       Form::Lettings::Pages::PersonKnown.new(nil, nil, self, person_index: 5),
       Form::Lettings::Pages::PersonRelationshipToLead.new(nil, nil, self, person_index: 5),
-      Form::Lettings::Pages::PersonAge.new(nil, nil, self, person_index: 5),
+      Form::Lettings::Pages::PersonAge.new(nil, nil, self, person_index: 5, is_child: true),
+      Form::Lettings::Pages::PersonAge.new(nil, nil, self, person_index: 5, is_child: false),
       Form::Lettings::Pages::NoFemalesPregnantHouseholdPersonAgeValueCheck.new(nil, nil, self,
                                                                                person_index: 5),
       Form::Lettings::Pages::FemalesInSoftAgeRangeInPregnantHouseholdPersonAgeValueCheck.new(nil, nil, self,
@@ -86,7 +90,8 @@ class Form::Lettings::Subsections::HouseholdCharacteristics < ::Form::Subsection
       Form::Lettings::Pages::PersonOverRetirementValueCheck.new(nil, nil, self, person_index: 5),
       Form::Lettings::Pages::PersonKnown.new(nil, nil, self, person_index: 6),
       Form::Lettings::Pages::PersonRelationshipToLead.new(nil, nil, self, person_index: 6),
-      Form::Lettings::Pages::PersonAge.new(nil, nil, self, person_index: 6),
+      Form::Lettings::Pages::PersonAge.new(nil, nil, self, person_index: 6, is_child: true),
+      Form::Lettings::Pages::PersonAge.new(nil, nil, self, person_index: 6, is_child: false),
       Form::Lettings::Pages::NoFemalesPregnantHouseholdPersonAgeValueCheck.new(nil, nil, self,
                                                                                person_index: 6),
       Form::Lettings::Pages::FemalesInSoftAgeRangeInPregnantHouseholdPersonAgeValueCheck.new(nil, nil, self,
@@ -100,7 +105,8 @@ class Form::Lettings::Subsections::HouseholdCharacteristics < ::Form::Subsection
       Form::Lettings::Pages::PersonOverRetirementValueCheck.new(nil, nil, self, person_index: 6),
       Form::Lettings::Pages::PersonKnown.new(nil, nil, self, person_index: 7),
       Form::Lettings::Pages::PersonRelationshipToLead.new(nil, nil, self, person_index: 7),
-      Form::Lettings::Pages::PersonAge.new(nil, nil, self, person_index: 7),
+      Form::Lettings::Pages::PersonAge.new(nil, nil, self, person_index: 7, is_child: true),
+      Form::Lettings::Pages::PersonAge.new(nil, nil, self, person_index: 7, is_child: false),
       Form::Lettings::Pages::NoFemalesPregnantHouseholdPersonAgeValueCheck.new(nil, nil, self,
                                                                                person_index: 7),
       Form::Lettings::Pages::FemalesInSoftAgeRangeInPregnantHouseholdPersonAgeValueCheck.new(nil, nil, self,
@@ -114,7 +120,8 @@ class Form::Lettings::Subsections::HouseholdCharacteristics < ::Form::Subsection
       Form::Lettings::Pages::PersonOverRetirementValueCheck.new(nil, nil, self, person_index: 7),
       Form::Lettings::Pages::PersonKnown.new(nil, nil, self, person_index: 8),
       Form::Lettings::Pages::PersonRelationshipToLead.new(nil, nil, self, person_index: 8),
-      Form::Lettings::Pages::PersonAge.new(nil, nil, self, person_index: 8),
+      Form::Lettings::Pages::PersonAge.new(nil, nil, self, person_index: 8, is_child: true),
+      Form::Lettings::Pages::PersonAge.new(nil, nil, self, person_index: 8, is_child: false),
       Form::Lettings::Pages::NoFemalesPregnantHouseholdPersonAgeValueCheck.new(nil, nil, self,
                                                                                person_index: 8),
       Form::Lettings::Pages::FemalesInSoftAgeRangeInPregnantHouseholdPersonAgeValueCheck.new(nil, nil, self,
diff --git a/app/models/log.rb b/app/models/log.rb
index d8aa9e236..4fd50f7bd 100644
--- a/app/models/log.rb
+++ b/app/models/log.rb
@@ -75,6 +75,12 @@ class Log < ApplicationRecord
     end
   end
 
+  (2..8).each do |person_num|
+    define_method("person_#{person_num}_child_relation?") do
+      send("relat#{person_num}") == "C"
+    end
+  end
+
 private
 
   def plural_gender_for_person(person_num)
diff --git a/spec/models/form/lettings/pages/person_age_spec.rb b/spec/models/form/lettings/pages/person_age_spec.rb
index ca39ef2c9..59cb3d22a 100644
--- a/spec/models/form/lettings/pages/person_age_spec.rb
+++ b/spec/models/form/lettings/pages/person_age_spec.rb
@@ -1,11 +1,12 @@
 require "rails_helper"
 
 RSpec.describe Form::Lettings::Pages::PersonAge, type: :model do
-  subject(:page) { described_class.new(nil, page_definition, subsection, person_index:) }
+  subject(:page) { described_class.new(nil, page_definition, subsection, person_index:, is_child:) }
 
   let(:page_definition) { nil }
   let(:subsection) { instance_double(Form::Subsection) }
   let(:person_index) { 2 }
+  let(:is_child) { false }
 
   it "has correct subsection" do
     expect(page.subsection).to eq(subsection)
@@ -24,14 +25,30 @@ RSpec.describe Form::Lettings::Pages::PersonAge, type: :model do
       expect(page.questions.map(&:id)).to eq(%w[age2_known age2])
     end
 
-    it "has the correct id" do
-      expect(page.id).to eq("person_2_age")
+    context "when child" do
+      let(:is_child) { true }
+
+      it "has the correct id" do
+        expect(page.id).to eq("person_2_age_child")
+      end
+
+      it "has correct depends_on" do
+        expect(page.depends_on).to eq(
+          [{ "details_known_2" => 0, "person_2_child_relation?" => true }],
+        )
+      end
     end
 
-    it "has correct depends_on" do
-      expect(page.depends_on).to eq(
-        [{ "details_known_2" => 0 }],
-      )
+    context "when not child" do
+      it "has the correct id" do
+        expect(page.id).to eq("person_2_age_non_child")
+      end
+
+      it "has correct depends_on" do
+        expect(page.depends_on).to eq(
+          [{ "details_known_2" => 0, "person_2_child_relation?" => false }],
+        )
+      end
     end
   end
 
@@ -43,12 +60,12 @@ RSpec.describe Form::Lettings::Pages::PersonAge, type: :model do
     end
 
     it "has the correct id" do
-      expect(page.id).to eq("person_3_age")
+      expect(page.id).to eq("person_3_age_non_child")
     end
 
     it "has correct depends_on" do
       expect(page.depends_on).to eq(
-        [{ "details_known_3" => 0 }],
+        [{ "details_known_3" => 0, "person_3_child_relation?" => false }],
       )
     end
   end
diff --git a/spec/models/form/lettings/questions/age_spec.rb b/spec/models/form/lettings/questions/age_spec.rb
index 87c3dce22..33a4e24d3 100644
--- a/spec/models/form/lettings/questions/age_spec.rb
+++ b/spec/models/form/lettings/questions/age_spec.rb
@@ -1,11 +1,12 @@
 require "rails_helper"
 
 RSpec.describe Form::Lettings::Questions::Age, type: :model do
-  subject(:question) { described_class.new(nil, question_definition, page, person_index:) }
+  subject(:question) { described_class.new(nil, question_definition, page, person_index:, is_child:) }
 
   let(:question_definition) { nil }
   let(:page) { instance_double(Form::Page) }
   let(:person_index) { 2 }
+  let(:is_child) { false }
 
   it "has correct page" do
     expect(question.page).to eq(page)
@@ -23,12 +24,22 @@ RSpec.describe Form::Lettings::Questions::Age, type: :model do
     expect(question.derived?).to be false
   end
 
-  it "has the correct hint" do
-    expect(question.hint_text).to be_nil
+  context "when child" do
+    let(:is_child) { true }
+
+    it "has the correct hint" do
+      expect(question.hint_text).to eq("For a child under 1, enter 1")
+    end
+  end
+
+  context "when not child" do
+    it "has no hint" do
+      expect(question.hint_text).to be nil
+    end
   end
 
   it "has the correct min" do
-    expect(question.min).to eq(0)
+    expect(question.min).to eq(1)
   end
 
   it "has the correct max" do
diff --git a/spec/models/form/lettings/subsections/household_characteristics_spec.rb b/spec/models/form/lettings/subsections/household_characteristics_spec.rb
index 96d722a2b..d0d55b8bf 100644
--- a/spec/models/form/lettings/subsections/household_characteristics_spec.rb
+++ b/spec/models/form/lettings/subsections/household_characteristics_spec.rb
@@ -36,7 +36,8 @@ RSpec.describe Form::Lettings::Subsections::HouseholdCharacteristics, type: :mod
         lead_tenant_over_retirement_value_check
         person_2_known
         person_2_relationship_to_lead
-        person_2_age
+        person_2_age_child
+        person_2_age_non_child
         no_females_pregnant_household_person_2_age_value_check
         females_in_soft_age_range_in_pregnant_household_person_2_age_value_check
         person_2_gender_identity
@@ -47,7 +48,8 @@ RSpec.describe Form::Lettings::Subsections::HouseholdCharacteristics, type: :mod
         person_2_over_retirement_value_check
         person_3_known
         person_3_relationship_to_lead
-        person_3_age
+        person_3_age_child
+        person_3_age_non_child
         no_females_pregnant_household_person_3_age_value_check
         females_in_soft_age_range_in_pregnant_household_person_3_age_value_check
         person_3_gender_identity
@@ -58,7 +60,8 @@ RSpec.describe Form::Lettings::Subsections::HouseholdCharacteristics, type: :mod
         person_3_over_retirement_value_check
         person_4_known
         person_4_relationship_to_lead
-        person_4_age
+        person_4_age_child
+        person_4_age_non_child
         no_females_pregnant_household_person_4_age_value_check
         females_in_soft_age_range_in_pregnant_household_person_4_age_value_check
         person_4_gender_identity
@@ -69,7 +72,8 @@ RSpec.describe Form::Lettings::Subsections::HouseholdCharacteristics, type: :mod
         person_4_over_retirement_value_check
         person_5_known
         person_5_relationship_to_lead
-        person_5_age
+        person_5_age_child
+        person_5_age_non_child
         no_females_pregnant_household_person_5_age_value_check
         females_in_soft_age_range_in_pregnant_household_person_5_age_value_check
         person_5_gender_identity
@@ -80,7 +84,8 @@ RSpec.describe Form::Lettings::Subsections::HouseholdCharacteristics, type: :mod
         person_5_over_retirement_value_check
         person_6_known
         person_6_relationship_to_lead
-        person_6_age
+        person_6_age_child
+        person_6_age_non_child
         no_females_pregnant_household_person_6_age_value_check
         females_in_soft_age_range_in_pregnant_household_person_6_age_value_check
         person_6_gender_identity
@@ -91,7 +96,8 @@ RSpec.describe Form::Lettings::Subsections::HouseholdCharacteristics, type: :mod
         person_6_over_retirement_value_check
         person_7_known
         person_7_relationship_to_lead
-        person_7_age
+        person_7_age_child
+        person_7_age_non_child
         no_females_pregnant_household_person_7_age_value_check
         females_in_soft_age_range_in_pregnant_household_person_7_age_value_check
         person_7_gender_identity
@@ -102,7 +108,8 @@ RSpec.describe Form::Lettings::Subsections::HouseholdCharacteristics, type: :mod
         person_7_over_retirement_value_check
         person_8_known
         person_8_relationship_to_lead
-        person_8_age
+        person_8_age_child
+        person_8_age_non_child
         no_females_pregnant_household_person_8_age_value_check
         females_in_soft_age_range_in_pregnant_household_person_8_age_value_check
         person_8_gender_identity