diff --git a/app/models/bulk_upload.rb b/app/models/bulk_upload.rb
index c7f211064..66d24bf8d 100644
--- a/app/models/bulk_upload.rb
+++ b/app/models/bulk_upload.rb
@@ -157,7 +157,7 @@ class BulkUpload
       mrcmonth: row[93],
       mrcyear: row[94],
       # supported_scheme: row[95],
-      startdate: row[96].to_s + row[97].to_s + row[98].to_s,
+      startdate: date_time(row[98], row[97], row[96]),
       # startdate_day: row[96],
       # startdate_month: row[97],
       # startdate_year: row[98],
@@ -201,6 +201,12 @@ class BulkUpload
     }
   end
 
+  def date_time(year, month, day)
+    return unless year && month && day
+
+    Time.zone.local("20#{year}", month.to_s, day.to_s)
+  end
+
   def other_hhmemb(row)
     [13, 14, 15, 16, 17, 18, 19].count { |idx| row[idx].present? }
   end
diff --git a/app/models/case_log.rb b/app/models/case_log.rb
index 042759733..4b9d196b9 100644
--- a/app/models/case_log.rb
+++ b/app/models/case_log.rb
@@ -35,10 +35,11 @@ class CaseLog < ApplicationRecord
   default_scope -> { kept }
 
   validates_with CaseLogValidator
-  before_save :update_status!
   before_validation :process_postcode_changes!, if: :property_postcode_changed?
+  before_validation :reset_invalidated_dependent_fields!
   before_validation :reset_location_fields!, unless: :postcode_known?
   before_validation :set_derived_fields!
+  before_save :update_status!
 
   belongs_to :owning_organisation, class_name: "Organisation"
   belongs_to :managing_organisation, class_name: "Organisation"
@@ -46,7 +47,6 @@ class CaseLog < ApplicationRecord
   scope :for_organisation, ->(org) { where(owning_organisation: org).or(where(managing_organisation: org)) }
 
   enum status: { "not_started" => 0, "in_progress" => 1, "completed" => 2 }
-
   enum ethnic: ETHNIC
   enum national: NATIONAL, _suffix: true
   enum ecstat1: ECSTAT, _suffix: true
@@ -135,10 +135,8 @@ class CaseLog < ApplicationRecord
   enum la_known: POLAR, _suffix: true
   enum net_income_known: NET_INCOME_KNOWN, _suffix: true
 
-  AUTOGENERATED_FIELDS = %w[id status created_at updated_at discarded_at renttype lettype is_la_inferred totchild totelder totadult incfreq tcharge].freeze
-  OPTIONAL_FIELDS = %w[postcode_known
-                       la_known
-                       first_time_property_let_as_social_housing].freeze
+  AUTOGENERATED_FIELDS = %w[id status created_at updated_at discarded_at].freeze
+  OPTIONAL_FIELDS = %w[postcode_known la_known first_time_property_let_as_social_housing].freeze
 
   def form
     FormHandler.instance.get_form(form_name)
@@ -212,6 +210,16 @@ private
                   end
   end
 
+  def reset_invalidated_dependent_fields!
+    form.invalidated_page_questions(self).each do |question|
+      public_send("#{question.id}=", nil) if respond_to?(question.id.to_s)
+    end
+  end
+
+  def dynamically_not_required
+    (form.invalidated_questions(self) + form.readonly_questions).map(&:id).uniq
+  end
+
   def set_derived_fields!
     if previous_postcode.present?
       self.ppostc1 = UKPostcode.parse(previous_postcode).outcode
@@ -295,62 +303,16 @@ private
   end
 
   def all_fields_completed?
-    mandatory_fields.none? { |_key, val| val.nil? }
+    mandatory_fields.none? { |field| public_send(field).nil? if respond_to?(field) }
   end
 
   def all_fields_nil?
     init_fields = %w[owning_organisation_id managing_organisation_id]
-    fields = mandatory_fields.except(*init_fields)
-    fields.all? { |_key, val| val.nil? }
+    fields = mandatory_fields.difference(init_fields)
+    fields.none? { |field| public_send(field).present? if respond_to?(field) }
   end
 
   def mandatory_fields
-    required = attributes.except(*(AUTOGENERATED_FIELDS + OPTIONAL_FIELDS))
-
-    dynamically_not_required = []
-
-    if reason != "Other"
-      dynamically_not_required << "other_reason_for_leaving_last_settled_home"
-    end
-
-    if earnings.to_i.zero?
-      dynamically_not_required << "incfreq"
-    end
-
-    if sale_or_letting == "Letting"
-      dynamically_not_required << "sale_completion_date"
-    end
-
-    if la.present?
-      dynamically_not_required << "why_dont_you_know_la"
-    end
-
-    if tenancy == "Secure (including flexible)"
-      dynamically_not_required << "tenancylength"
-    end
-
-    unless net_income_in_soft_max_range? || net_income_in_soft_min_range?
-      dynamically_not_required << "override_net_income_validation"
-    end
-
-    unless tenancy == "Other"
-      dynamically_not_required << "tenancyother"
-    end
-
-    dynamically_not_required << if net_income_known == "Tenant prefers not to say"
-                                  "earnings"
-                                else
-                                  "incref"
-                                end
-
-    start_range = (other_hhmemb || 0) + 2
-    (start_range..8).each do |n|
-      dynamically_not_required << "age#{n}"
-      dynamically_not_required << "sex#{n}"
-      dynamically_not_required << "relat#{n}"
-      dynamically_not_required << "ecstat#{n}"
-    end
-
-    required.delete_if { |key, _value| dynamically_not_required.include?(key) }
+    form.questions.map(&:id).difference(OPTIONAL_FIELDS, dynamically_not_required)
   end
 end
diff --git a/app/models/form.rb b/app/models/form.rb
index 370a3cd41..4474eae8e 100644
--- a/app/models/form.rb
+++ b/app/models/form.rb
@@ -53,4 +53,24 @@ class Form
       c.map { |k, v| v.keys.map { |key| Hash(from: k, to: key, cond: v[key]) } }
     }.flatten
   end
+
+  def invalidated_pages(case_log)
+    pages.reject { |p| p.routed_to?(case_log) }
+  end
+
+  def invalidated_questions(case_log)
+    (invalidated_page_questions(case_log) + invalidated_conditional_questions(case_log)).uniq
+  end
+
+  def invalidated_page_questions(case_log)
+    invalidated_pages(case_log).flat_map(&:questions) || []
+  end
+
+  def invalidated_conditional_questions(case_log)
+    questions.reject { |q| q.enabled?(case_log) } || []
+  end
+
+  def readonly_questions
+    questions.select(&:read_only?)
+  end
 end
diff --git a/app/models/form/page.rb b/app/models/form/page.rb
index 12b1065d6..c550114a2 100644
--- a/app/models/form/page.rb
+++ b/app/models/form/page.rb
@@ -22,6 +22,14 @@ class Form::Page
   end
 
   def routed_to?(case_log)
+    return true unless depends_on || subsection.depends_on
+
+    subsection.enabled?(case_log) && depends_on_met(case_log)
+  end
+
+private
+
+  def depends_on_met(case_log)
     return true unless depends_on
 
     depends_on.all? do |question, value|
diff --git a/app/models/form/question.rb b/app/models/form/question.rb
index 2bf2d4345..edbf96178 100644
--- a/app/models/form/question.rb
+++ b/app/models/form/question.rb
@@ -80,7 +80,7 @@ class Form::Question
     # Special case as No is a valid answer but doesn't let you progress and use the service
     return false if id == "gdpr_acceptance" && case_log[id] == "No"
 
-    case_log[id].present?
+    case_log[id].present? || !case_log.respond_to?(id.to_sym)
   end
 
 private
diff --git a/spec/factories/case_log.rb b/spec/factories/case_log.rb
index 8a133549b..c472d6f40 100644
--- a/spec/factories/case_log.rb
+++ b/spec/factories/case_log.rb
@@ -38,7 +38,7 @@ FactoryBot.define do
       tenant_code { "BZ737" }
       postcode { "NW1 7TY" }
       age1 { 35 }
-      sex1 { "F" }
+      sex1 { "Female" }
       ethnic { 2 }
       national { 4 }
       prevten { "Private sector tenancy" }
@@ -54,7 +54,7 @@ FactoryBot.define do
       leftreg { "No - they left up to 5 years ago" }
       reservist { "No" }
       illness { "Yes" }
-      preg_occ { "No" }
+      preg_occ { "Yes" }
       accessibility_requirements { "No" }
       condition_effects { "dummy" }
       tenancy_code { "BZ757" }
diff --git a/spec/features/form/validations_spec.rb b/spec/features/form/validations_spec.rb
index 4aa72e261..0ba1eff37 100644
--- a/spec/features/form/validations_spec.rb
+++ b/spec/features/form/validations_spec.rb
@@ -102,6 +102,24 @@ RSpec.describe "validations" do
     end
   end
 
+  describe "Compound validations" do
+    context "when you select two compatible answers, that become incompatible if the first answer changes", js: true do
+      it "clears the second answer on change of the first" do
+        case_log.update!(other_hhmemb: 1, relat2: "Partner", age2: 32, sex2: "Female", ecstat2: "Not seeking work")
+        visit("/logs/#{id}/conditional-question")
+        choose("case-log-preg-occ-yes-field", allow_label_click: true)
+        click_button("Save and continue")
+        choose("case-log-cbl-yes-field", allow_label_click: true)
+        click_button("Save and continue")
+        page.go_back
+        click_link("Back")
+        choose("case-log-preg-occ-no-field", allow_label_click: true)
+        click_button("Save and continue")
+        expect(case_log.reload.cbl).to be_nil
+      end
+    end
+  end
+
   describe "Soft Validation" do
     context "given a weekly net income that is above the expected amount for the given economic status but below the hard max" do
       let(:case_log) do
diff --git a/spec/fixtures/complete_case_log.json b/spec/fixtures/complete_case_log.json
index 3683832c9..1c8b61097 100644
--- a/spec/fixtures/complete_case_log.json
+++ b/spec/fixtures/complete_case_log.json
@@ -50,10 +50,10 @@
     "accessibility_requirements": "No",
     "condition_effects": "dummy",
     "tenancy_code": "BZ757",
-    "startdate": "12/12/2020",
+    "startdate": "12/12/2021",
     "day": 12,
     "month": 12,
-    "year": 2020,
+    "year": 2021,
     "startertenancy": "No",
     "tenancylength": "5",
     "tenancy": "Secure (including flexible)",
diff --git a/spec/fixtures/files/2021_22_lettings_bulk_upload.xlsx b/spec/fixtures/files/2021_22_lettings_bulk_upload.xlsx
index c8e86cdbe..ee6644dd4 100644
Binary files a/spec/fixtures/files/2021_22_lettings_bulk_upload.xlsx and b/spec/fixtures/files/2021_22_lettings_bulk_upload.xlsx differ
diff --git a/spec/fixtures/forms/2021_2022.json b/spec/fixtures/forms/2021_2022.json
index 7bcc5df4f..6edb3608b 100644
--- a/spec/fixtures/forms/2021_2022.json
+++ b/spec/fixtures/forms/2021_2022.json
@@ -596,7 +596,7 @@
                 "header": "",
                 "description": "",
                 "questions": {
-                  "why_dont_you_know_la": {
+                  "reason": {
                     "check_answer_label": "Reason for not knowing local authority",
                     "header": "Give a reason why you don’t know the postcode or local authority",
                     "hint_text": "",
diff --git a/spec/models/case_log_spec.rb b/spec/models/case_log_spec.rb
index 5c2e8f5be..b0fd2dd6b 100644
--- a/spec/models/case_log_spec.rb
+++ b/spec/models/case_log_spec.rb
@@ -722,8 +722,8 @@ RSpec.describe Form, type: :model do
       it "cannot be later than the tenancy start date" do
         expect {
           CaseLog.create!(
-            mrcdate: Date.new(2020, 10, 10),
-            startdate: Date.new(2020, 10, 9),
+            mrcdate: Date.new(2021, 10, 10),
+            startdate: Date.new(2021, 10, 9),
             owning_organisation: owning_organisation,
             managing_organisation: managing_organisation,
           )
@@ -731,8 +731,8 @@ RSpec.describe Form, type: :model do
 
         expect {
           CaseLog.create!(
-            mrcdate: Date.new(2020, 10, 9),
-            startdate: Date.new(2020, 10, 10),
+            mrcdate: Date.new(2021, 10, 9),
+            startdate: Date.new(2021, 10, 10),
             owning_organisation: owning_organisation,
             managing_organisation: managing_organisation,
           )
@@ -771,7 +771,7 @@ RSpec.describe Form, type: :model do
       it "must have less than two years between the tenancy start date and major repairs date" do
         expect {
           CaseLog.create!(
-            startdate: Date.new(2020, 10, 10),
+            startdate: Date.new(2021, 10, 10),
             mrcdate: Date.new(2017, 10, 10),
             owning_organisation: owning_organisation,
             managing_organisation: managing_organisation,
@@ -784,7 +784,7 @@ RSpec.describe Form, type: :model do
       it "must have less than 10 years between the tenancy start date and void" do
         expect {
           CaseLog.create!(
-            startdate: Date.new(2020, 10, 10),
+            startdate: Date.new(2021, 10, 10),
             property_void_date: Date.new(2009, 10, 10),
             owning_organisation: owning_organisation,
             managing_organisation: managing_organisation,
@@ -793,7 +793,7 @@ RSpec.describe Form, type: :model do
 
         expect {
           CaseLog.create!(
-            startdate: Date.new(2020, 10, 10),
+            startdate: Date.new(2021, 10, 10),
             property_void_date: Date.new(2015, 10, 10),
             owning_organisation: owning_organisation,
             managing_organisation: managing_organisation,
@@ -804,8 +804,8 @@ RSpec.describe Form, type: :model do
       it "must be before the tenancy start date" do
         expect {
           CaseLog.create!(
-            startdate: Date.new(2020, 10, 10),
-            property_void_date: Date.new(2021, 10, 10),
+            startdate: Date.new(2021, 10, 10),
+            property_void_date: Date.new(2021, 10, 11),
             owning_organisation: owning_organisation,
             managing_organisation: managing_organisation,
           )
@@ -813,7 +813,7 @@ RSpec.describe Form, type: :model do
 
         expect {
           CaseLog.create!(
-            startdate: Date.new(2020, 10, 10),
+            startdate: Date.new(2021, 10, 10),
             property_void_date: Date.new(2019, 10, 10),
             owning_organisation: owning_organisation,
             managing_organisation: managing_organisation,
@@ -824,7 +824,7 @@ RSpec.describe Form, type: :model do
       it "must be before major repairs date if major repairs date provided" do
         expect {
           CaseLog.create!(
-            startdate: Date.new(2020, 10, 10),
+            startdate: Date.new(2021, 10, 10),
             mrcdate: Date.new(2019, 10, 10),
             property_void_date: Date.new(2019, 11, 11),
             owning_organisation: owning_organisation,
diff --git a/spec/models/form/page_spec.rb b/spec/models/form/page_spec.rb
index a0eac90e9..403227e83 100644
--- a/spec/models/form/page_spec.rb
+++ b/spec/models/form/page_spec.rb
@@ -63,5 +63,17 @@ RSpec.describe Form::Page, type: :model do
         expect(subject.routed_to?(case_log)).to be true
       end
     end
+
+    context "when the page's subsection has routing conditions" do
+      let(:section_id) { "submission" }
+      let(:subsection_id) { "declaration" }
+      let(:page_id) { "declaration" }
+      let(:completed_case_log) { FactoryBot.build(:case_log, :completed, incfreq: "Weekly") }
+
+      it "evaluates the sections dependencies" do
+        expect(subject.routed_to?(case_log)).to be false
+        expect(subject.routed_to?(completed_case_log)).to be true
+      end
+    end
   end
 end