diff --git a/app/models/derived_variables/lettings_log_variables.rb b/app/models/derived_variables/lettings_log_variables.rb
index 230b2a1dc..1803638dd 100644
--- a/app/models/derived_variables/lettings_log_variables.rb
+++ b/app/models/derived_variables/lettings_log_variables.rb
@@ -176,9 +176,13 @@ module DerivedVariables::LettingsLogVariables
 
     if !form.start_year_2026_or_later? && is_supported_housing?
       reset_address_fields!
-    elsif form.start_year_2026_or_later? && location_changed?
-      reset_address_fields!
-      self.la = nil
+    elsif form.start_year_2026_or_later?
+      if location_changed?
+        reset_address_fields!
+        self.la = nil
+      end
+
+      self.is_la_inferred = la.present? if is_supported_housing? && location && self[:la].blank?
     end
 
     if scheme_has_confidential_information?
diff --git a/app/models/form/lettings/pages/property_local_authority.rb b/app/models/form/lettings/pages/property_local_authority.rb
index 5656ec2d9..f552776a0 100644
--- a/app/models/form/lettings/pages/property_local_authority.rb
+++ b/app/models/form/lettings/pages/property_local_authority.rb
@@ -5,6 +5,7 @@ class Form::Lettings::Pages::PropertyLocalAuthority < ::Form::Page
     @depends_on = [
       { "is_la_inferred" => false, "is_general_needs?" => true, "form.start_year_2025_or_later?" => false, "address_search_given?" => true },
       { "is_la_inferred" => false, "is_general_needs?" => true, "form.start_year_2025_or_later?" => true },
+      { "is_la_inferred" => false, "is_supported_housing?" => true, "form.start_year_2026_or_later?" => true },
     ]
   end
 
diff --git a/app/models/lettings_log.rb b/app/models/lettings_log.rb
index 1eb9078ff..f5c153f66 100644
--- a/app/models/lettings_log.rb
+++ b/app/models/lettings_log.rb
@@ -31,7 +31,7 @@ class LettingsLog < Log
   before_validation :process_postcode_changes!, if: :postcode_full_changed?
   before_validation :process_previous_postcode_changes!, if: :ppostcode_full_changed?
   before_validation :reset_invalidated_dependent_fields!
-  before_validation :reset_location_fields!, unless: :postcode_known?
+  before_validation :reset_location_fields!, unless: :postcode_known_or_la_derived_from_scheme_location?
   before_validation :reset_previous_location_fields!, unless: :previous_postcode_known?
   before_validation :set_derived_fields!
   before_validation :process_uprn_change!, if: :should_process_uprn_change?
@@ -375,6 +375,10 @@ class LettingsLog < Log
     postcode_known == 1
   end
 
+  def postcode_known_or_la_derived_from_scheme_location?
+    postcode_known? || (form&.start_year_2026_or_later? && is_supported_housing? && location.present?)
+  end
+
   def previous_postcode_known?
     # 0: Yes
     ppcodenk&.zero?
diff --git a/lib/tasks/clear_confidential_address_data.rake b/lib/tasks/clear_confidential_address_data.rake
new file mode 100644
index 000000000..eff626728
--- /dev/null
+++ b/lib/tasks/clear_confidential_address_data.rake
@@ -0,0 +1,75 @@
+desc "Clears already-collected address/UPRN data for 2026/27 lettings logs in confidential (sensitive) schemes"
+task clear_confidential_address_data: :environment do
+  year = 2026
+
+  fields_present_scope = %w[
+    uprn
+    uprn_known
+    uprn_confirmed
+    uprn_selection
+    address_line1
+    address_line2
+    town_or_city
+    county
+    postcode_full
+    postcode_known
+    address_line1_input
+    postcode_full_input
+    address_line1_as_entered
+    address_line2_as_entered
+    town_or_city_as_entered
+    county_as_entered
+    postcode_full_as_entered
+    la_as_entered
+    address_search_value_check
+    la
+  ]
+
+  scope = LettingsLog
+            .filter_by_year(year)
+            .joins(:scheme)
+            .where(schemes: { sensitive: "Yes" })
+            .where(fields_present_scope.map { |field| "#{LettingsLog.table_name}.#{field} IS NOT NULL" }.join(" OR "))
+
+  puts "Found #{scope.count} confidential-scheme lettings logs in #{year}/#{year + 1} with address data to clear"
+  scope.find_each do |log|
+    puts "log_id=#{log.id} scheme_id=#{log.scheme_id} location_id=#{log.location_id} status=#{log.status} la=#{log.la} postcode_full=#{log.postcode_full}"
+  end
+
+  updated = 0
+
+  scope.find_each do |log|
+    original_status = log.status
+
+    log.uprn = nil
+    log.uprn_known = nil
+    log.uprn_confirmed = nil
+    log.uprn_selection = nil
+    log.address_line1 = nil
+    log.address_line2 = nil
+    log.town_or_city = nil
+    log.county = nil
+    log.postcode_full = nil
+    log.postcode_known = nil
+    log.address_line1_input = nil
+    log.postcode_full_input = nil
+    log.address_line1_as_entered = nil
+    log.address_line2_as_entered = nil
+    log.town_or_city_as_entered = nil
+    log.county_as_entered = nil
+    log.postcode_full_as_entered = nil
+    log.la_as_entered = nil
+    log.address_search_value_check = nil
+    log.la = nil
+    log.is_la_inferred = log.la.present?
+
+    if log.save(validate: false)
+      updated += 1
+      puts "log_id=#{log.id} status changed: #{original_status} -> #{log.status}" if log.status != original_status
+    else
+      Rails.logger.error "CLDC-4462: failed to clear address data for log #{log.id}: #{log.errors.full_messages.join(', ')}"
+    end
+  end
+
+  puts "#{updated} logs updated"
+end
diff --git a/spec/lib/tasks/clear_confidential_address_data_spec.rb b/spec/lib/tasks/clear_confidential_address_data_spec.rb
new file mode 100644
index 000000000..65639f0cd
--- /dev/null
+++ b/spec/lib/tasks/clear_confidential_address_data_spec.rb
@@ -0,0 +1,141 @@
+require "rails_helper"
+require "rake"
+
+RSpec.describe "clear_confidential_address_data" do
+  describe ":clear_confidential_address_data", type: :task do
+    subject(:task) { Rake::Task["clear_confidential_address_data"] }
+
+    before do
+      Rake.application.rake_require("tasks/clear_confidential_address_data")
+      Rake::Task.define_task(:environment)
+      task.reenable
+    end
+
+    let(:owning_organisation) { create(:organisation) }
+    let(:scheme) { create(:scheme, sensitive: "Yes", owning_organisation:) }
+    let(:non_confidential_scheme) { create(:scheme, sensitive: "No", owning_organisation:) }
+    let(:location) { create(:location, scheme:) }
+
+    def create_log_with_address_data(scheme:, location:, startdate:)
+      log = create(
+        :lettings_log,
+        :completed,
+        :sh,
+        :ignore_validation_errors,
+        owning_organisation:,
+        managing_organisation: owning_organisation,
+        scheme:,
+        location:,
+        startdate:,
+      )
+      # Bypass callbacks/validations to simulate a log that already holds property
+      # address/UPRN data collected before the confidential address feature existed.
+      log.update_columns(
+        uprn: "123456789012",
+        address_line1: "1 Secret Street",
+        town_or_city: "Secretville",
+        postcode_known: 1,
+        la: "E09000003",
+      )
+      log
+    end
+
+    context "when a confidential-scheme log in 2026/27 has address data" do
+      let!(:log) { create_log_with_address_data(scheme:, location:, startdate: Time.zone.local(2026, 5, 1)) }
+
+      it "clears the address and UPRN fields" do
+        task.invoke
+        log.reload
+
+        expect(log.address_line1).to be_nil
+        expect(log.town_or_city).to be_nil
+        expect(log.uprn).to be_nil
+        expect(log.postcode_known).to be_nil
+      end
+
+      it "keeps the log's status unchanged when the location's LA can be inferred" do
+        task.invoke
+        expect(log.reload.status).to eq("completed")
+      end
+
+      it "resolves the local authority from the scheme's location without persisting it" do
+        task.invoke
+        log.reload
+
+        expect(log.la).to eq(location.location_code)
+        expect(log[:la]).to be_nil
+        expect(log.is_la_inferred).to be true
+      end
+    end
+
+    context "when the scheme's location has no resolvable local authority" do
+      let!(:log) { create_log_with_address_data(scheme:, location:, startdate: Time.zone.local(2026, 5, 1)) }
+
+      before { location.update_columns(location_code: nil, location_admin_district: nil, is_la_inferred: false) }
+
+      it "clears the address fields and forces the log to in_progress" do
+        task.invoke
+        log.reload
+
+        expect(log.address_line1).to be_nil
+        expect(log.la).to be_nil
+        expect(log.status).to eq("in_progress")
+      end
+    end
+
+    context "when the confidential-scheme log is outside the 2026/27 collection year" do
+      let!(:log) { create_log_with_address_data(scheme:, location:, startdate: Time.zone.local(2025, 5, 1)) }
+
+      it "does not clear the address fields" do
+        task.invoke
+        expect(log.reload.address_line1).to eq("1 Secret Street")
+      end
+    end
+
+    context "when the log's scheme is not confidential" do
+      let!(:log) { create_log_with_address_data(scheme: non_confidential_scheme, location:, startdate: Time.zone.local(2026, 5, 1)) }
+
+      it "does not clear the address fields" do
+        task.invoke
+        expect(log.reload.address_line1).to eq("1 Secret Street")
+      end
+    end
+
+    context "when a confidential-scheme 2026/27 log has no address data left" do
+      let!(:log) do
+        create(
+          :lettings_log,
+          :ignore_validation_errors,
+          needstype: 2,
+          owning_organisation:,
+          managing_organisation: owning_organisation,
+          scheme:,
+          location:,
+          startdate: Time.zone.local(2026, 5, 1),
+        )
+      end
+
+      it "is not touched" do
+        expect { task.invoke }.not_to(change { log.reload.updated_at })
+      end
+    end
+
+    it "does not affect the scheme or location associations" do
+      log = create_log_with_address_data(scheme:, location:, startdate: Time.zone.local(2026, 5, 1))
+
+      task.invoke
+      log.reload
+
+      expect(log.scheme_id).to eq(scheme.id)
+      expect(log.location_id).to eq(location.id)
+    end
+
+    it "is idempotent" do
+      log = create_log_with_address_data(scheme:, location:, startdate: Time.zone.local(2026, 5, 1))
+
+      task.invoke
+      task.reenable
+      expect { task.invoke }.not_to(change { log.reload.updated_at })
+    end
+  end
+end