diff --git a/app/models/form/sales/pages/service_charge.rb b/app/models/form/sales/pages/service_charge.rb
index a0102eda4..e938a3e56 100644
--- a/app/models/form/sales/pages/service_charge.rb
+++ b/app/models/form/sales/pages/service_charge.rb
@@ -6,8 +6,8 @@ class Form::Sales::Pages::ServiceCharge < ::Form::Page
 
   def questions
     @questions ||= [
-      Form::Sales::Questions::HasServiceCharge.new(nil, nil, self),
-      Form::Sales::Questions::ServiceCharge.new(nil, nil, self),
+      Form::Sales::Questions::HasServiceCharge.new(nil, nil, self, staircasing: false),
+      Form::Sales::Questions::ServiceCharge.new(nil, nil, self, staircasing: false),
     ]
   end
 end
diff --git a/app/models/form/sales/pages/service_charge_staircasing.rb b/app/models/form/sales/pages/service_charge_staircasing.rb
new file mode 100644
index 000000000..4e4f65c9e
--- /dev/null
+++ b/app/models/form/sales/pages/service_charge_staircasing.rb
@@ -0,0 +1,13 @@
+class Form::Sales::Pages::ServiceChargeStaircasing < ::Form::Page
+  def initialize(id, hsh, subsection)
+    super
+    @copy_key = "sales.sale_information.servicecharges"
+  end
+
+  def questions
+    @questions ||= [
+      Form::Sales::Questions::HasServiceCharge.new(nil, nil, self, staircasing: true),
+      Form::Sales::Questions::ServiceCharge.new(nil, nil, self, staircasing: true),
+    ]
+  end
+end
diff --git a/app/models/form/sales/questions/has_service_charge.rb b/app/models/form/sales/questions/has_service_charge.rb
index 41bf5f809..708c32f0d 100644
--- a/app/models/form/sales/questions/has_service_charge.rb
+++ b/app/models/form/sales/questions/has_service_charge.rb
@@ -1,6 +1,6 @@
 class Form::Sales::Questions::HasServiceCharge < ::Form::Question
-  def initialize(id, hsh, subsection)
-    super
+  def initialize(id, hsh, subsection, staircasing:)
+    super(id, hsh, subsection)
     @id = "has_mscharge"
     @type = "radio"
     @answer_options = ANSWER_OPTIONS
@@ -15,7 +15,8 @@ class Form::Sales::Questions::HasServiceCharge < ::Form::Question
       ],
     }
     @copy_key = "sales.sale_information.servicecharges.has_servicecharge"
-    @question_number = QUESTION_NUMBER_FROM_YEAR[form.start_date.year] || QUESTION_NUMBER_FROM_YEAR[QUESTION_NUMBER_FROM_YEAR.keys.max]
+    @staircasing = staircasing
+    @question_number = question_number_from_year[form.start_date.year] || question_number_from_year[question_number_from_year.keys.max]
   end
 
   ANSWER_OPTIONS = {
@@ -23,5 +24,11 @@ class Form::Sales::Questions::HasServiceCharge < ::Form::Question
     "0" => { "value" => "No" },
   }.freeze
 
-  QUESTION_NUMBER_FROM_YEAR = { 2025 => 88 }.freeze
+  def question_number_from_year
+    if @staircasing
+      { 2026 => 0 }.freeze
+    else
+      { 2025 => 88, 2026 => 0 }.freeze
+    end
+  end
 end
diff --git a/app/models/form/sales/questions/service_charge.rb b/app/models/form/sales/questions/service_charge.rb
index 6b9a76a94..f3aec4a2b 100644
--- a/app/models/form/sales/questions/service_charge.rb
+++ b/app/models/form/sales/questions/service_charge.rb
@@ -1,16 +1,24 @@
 class Form::Sales::Questions::ServiceCharge < ::Form::Question
-  def initialize(id, hsh, subsection)
-    super
+  def initialize(id, hsh, subsection, staircasing:)
+    super(id, hsh, subsection)
     @id = "mscharge"
     @type = "numeric"
     @min = 1
+    @max = 9999.99
     @step = 0.01
     @width = 5
     @prefix = "£"
     @copy_key = "sales.sale_information.servicecharges.servicecharge"
-    @question_number = QUESTION_NUMBER_FROM_YEAR[form.start_date.year] || QUESTION_NUMBER_FROM_YEAR[QUESTION_NUMBER_FROM_YEAR.keys.max]
+    @staircasing = staircasing
+    @question_number = question_number_from_year[form.start_date.year] || question_number_from_year[question_number_from_year.keys.max]
     @strip_commas = true
   end
 
-  QUESTION_NUMBER_FROM_YEAR = { 2025 => 88 }.freeze
+  def question_number_from_year
+    if @staircasing
+      { 2026 => 0 }.freeze
+    else
+      { 2025 => 88, 2026 => 0 }.freeze
+    end
+  end
 end
diff --git a/app/models/form/sales/subsections/shared_ownership_staircasing_transaction.rb b/app/models/form/sales/subsections/shared_ownership_staircasing_transaction.rb
index cc10ed28c..cfd00e5e1 100644
--- a/app/models/form/sales/subsections/shared_ownership_staircasing_transaction.rb
+++ b/app/models/form/sales/subsections/shared_ownership_staircasing_transaction.rb
@@ -25,6 +25,7 @@ class Form::Sales::Subsections::SharedOwnershipStaircasingTransaction < ::Form::
       Form::Sales::Pages::Mortgageused.new("staircase_mortgage_used_shared_ownership", nil, self, ownershipsch: 1),
       Form::Sales::Pages::MonthlyRentStaircasingOwned.new(nil, nil, self),
       Form::Sales::Pages::MonthlyRentStaircasing.new(nil, nil, self),
+      (Form::Sales::Pages::ServiceChargeStaircasing.new("service_charge_staircasing", nil, self) if form.start_year_2026_or_later?),
       Form::Sales::Pages::MonthlyChargesValueCheck.new("monthly_charges_shared_ownership_value_check", nil, self),
     ].compact
   end
diff --git a/app/services/csv/sales_log_csv_service.rb b/app/services/csv/sales_log_csv_service.rb
index 07ccad82c..b386b070f 100644
--- a/app/services/csv/sales_log_csv_service.rb
+++ b/app/services/csv/sales_log_csv_service.rb
@@ -249,7 +249,7 @@ module Csv
       return @attributes unless @user.support?
 
       mappings = SUPPORT_ATTRIBUTE_NAME_MAPPINGS
-      mappings = mappings.merge(SUPPORT_ATTRIBUTE_NAME_MAPPINGS_2025) if @year == 2025
+      mappings = mappings.merge(SUPPORT_ATTRIBUTE_NAME_MAPPINGS_2025) if @year >= 2025
 
       @attributes.map do |attribute|
         mappings[attribute] || attribute.upcase
@@ -297,11 +297,10 @@ module Csv
     end
 
     def attribute_mappings
-      mappings = case @year
-                 when 2024
-                   ATTRIBUTE_MAPPINGS.merge(ATTRIBUTE_MAPPINGS_2024)
-                 when 2025
+      mappings = if @year >= 2025
                    ATTRIBUTE_MAPPINGS.merge(ATTRIBUTE_MAPPINGS_2024).merge(ATTRIBUTE_MAPPINGS_2025)
+                 elsif @year == 2024
+                   ATTRIBUTE_MAPPINGS.merge(ATTRIBUTE_MAPPINGS_2024)
                  else
                    ATTRIBUTE_MAPPINGS
                  end
@@ -348,6 +347,8 @@ module Csv
         %w[id status duplicate_set_id created_at updated_at collection_start_year creation_method bulk_upload_id is_dpo]
       when 2025
         %w[id status duplicate_set_id created_at created_by_id updated_at updated_by_id creation_method bulk_upload_id]
+      when 2026
+        %w[id status duplicate_set_id created_at created_by_id updated_at updated_by_id creation_method bulk_upload_id]
       else
         %w[id status duplicate_set_id created_at updated_at collection_start_year creation_method bulk_upload_id is_dpo]
       end
diff --git a/spec/models/form/sales/pages/service_charge_staircasing_spec.rb b/spec/models/form/sales/pages/service_charge_staircasing_spec.rb
new file mode 100644
index 000000000..a29df7b82
--- /dev/null
+++ b/spec/models/form/sales/pages/service_charge_staircasing_spec.rb
@@ -0,0 +1,29 @@
+require "rails_helper"
+
+RSpec.describe Form::Sales::Pages::ServiceChargeStaircasing, type: :model do
+  subject(:page) { described_class.new(page_id, page_definition, subsection) }
+
+  let(:page_id) { nil }
+  let(:page_definition) { nil }
+  let(:subsection) { instance_double(Form::Subsection, form: instance_double(Form, start_date: Time.zone.local(2026, 4, 1))) }
+
+  it "has correct subsection" do
+    expect(page.subsection).to eq(subsection)
+  end
+
+  it "has correct questions" do
+    expect(page.questions.map(&:id)).to eq(%w[has_mscharge mscharge])
+  end
+
+  it "has the correct id" do
+    expect(page.id).to be_nil
+  end
+
+  it "has the correct description" do
+    expect(page.description).to be_nil
+  end
+
+  it "has correct depends_on" do
+    expect(page.depends_on).to be_nil
+  end
+end
diff --git a/spec/models/form/sales/questions/has_service_charge_spec.rb b/spec/models/form/sales/questions/has_service_charge_spec.rb
index bf0bd9d25..d64609bb0 100644
--- a/spec/models/form/sales/questions/has_service_charge_spec.rb
+++ b/spec/models/form/sales/questions/has_service_charge_spec.rb
@@ -1,12 +1,14 @@
 require "rails_helper"
 
 RSpec.describe Form::Sales::Questions::HasServiceCharge, type: :model do
-  subject(:question) { described_class.new(question_id, question_definition, page) }
+  subject(:question) { described_class.new(question_id, question_definition, page, staircasing:) }
 
-  let(:form) { instance_double(Form, start_date: Time.zone.local(2025, 4, 4)) }
   let(:question_id) { nil }
   let(:question_definition) { nil }
-  let(:page) { instance_double(Form::Page, subsection: instance_double(Form::Subsection, id: "shared_ownership", form:)) }
+  let(:subsection) { instance_double(Form::Subsection, form: instance_double(Form, start_date:)) }
+  let(:page) { instance_double(Form::Page, subsection:) }
+  let(:start_date) { Time.utc(2025, 5, 1) }
+  let(:staircasing) { false }
 
   it "has correct page" do
     expect(question.page).to eq(page)
@@ -46,4 +48,44 @@ RSpec.describe Form::Sales::Questions::HasServiceCharge, type: :model do
       ],
     })
   end
+
+  context "with 2025/26 form" do
+    let(:start_date) { Time.utc(2025, 4, 1) }
+
+    before do
+      allow(subsection.form).to receive(:start_year_2025_or_later?).and_return(true)
+    end
+
+    context "when not staircasing" do
+      let(:staircasing) { false }
+
+      it "has the correct question number" do
+        expect(question.question_number).to eq(88)
+      end
+    end
+  end
+
+  context "with 2026/27 form" do
+    let(:start_date) { Time.utc(2026, 4, 1) }
+
+    before do
+      allow(subsection.form).to receive(:start_year_2026_or_later?).and_return(true)
+    end
+
+    context "when staircasing" do
+      let(:staircasing) { true }
+
+      it "has the correct question number" do
+        expect(question.question_number).to eq(0)
+      end
+    end
+
+    context "when not staircasing" do
+      let(:staircasing) { false }
+
+      it "has the correct question number" do
+        expect(question.question_number).to eq(0)
+      end
+    end
+  end
 end
diff --git a/spec/models/form/sales/questions/service_charge_spec.rb b/spec/models/form/sales/questions/service_charge_spec.rb
index 56dee01cf..21104d2b5 100644
--- a/spec/models/form/sales/questions/service_charge_spec.rb
+++ b/spec/models/form/sales/questions/service_charge_spec.rb
@@ -1,11 +1,14 @@
 require "rails_helper"
 
 RSpec.describe Form::Sales::Questions::ServiceCharge, type: :model do
-  subject(:question) { described_class.new(question_id, question_definition, page) }
+  subject(:question) { described_class.new(question_id, question_definition, page, staircasing:) }
 
   let(:question_id) { nil }
   let(:question_definition) { nil }
-  let(:page) { instance_double(Form::Page, subsection: instance_double(Form::Subsection, form: instance_double(Form, start_date: Time.zone.local(2023, 4, 1)))) }
+  let(:subsection) { instance_double(Form::Subsection, form: instance_double(Form, start_date:)) }
+  let(:page) { instance_double(Form::Page, subsection:) }
+  let(:start_date) { Time.utc(2023, 4, 1) }
+  let(:staircasing) { false }
 
   it "has correct page" do
     expect(question.page).to eq(page)
@@ -34,4 +37,44 @@ RSpec.describe Form::Sales::Questions::ServiceCharge, type: :model do
   it "has the correct prefix" do
     expect(question.prefix).to eq("£")
   end
+
+  context "with 2025/26 form" do
+    let(:start_date) { Time.utc(2025, 4, 1) }
+
+    before do
+      allow(subsection.form).to receive(:start_year_2025_or_later?).and_return(true)
+    end
+
+    context "when not staircasing" do
+      let(:staircasing) { false }
+
+      it "has the correct question number" do
+        expect(question.question_number).to eq(88)
+      end
+    end
+  end
+
+  context "with 2026/27 form" do
+    let(:start_date) { Time.utc(2026, 4, 1) }
+
+    before do
+      allow(subsection.form).to receive(:start_year_2026_or_later?).and_return(true)
+    end
+
+    context "when staircasing" do
+      let(:staircasing) { true }
+
+      it "has the correct question number" do
+        expect(question.question_number).to eq(0)
+      end
+    end
+
+    context "when not staircasing" do
+      let(:staircasing) { false }
+
+      it "has the correct question number" do
+        expect(question.question_number).to eq(0)
+      end
+    end
+  end
 end
diff --git a/spec/models/form/sales/subsections/shared_ownership_staircasing_transaction_spec.rb b/spec/models/form/sales/subsections/shared_ownership_staircasing_transaction_spec.rb
new file mode 100644
index 000000000..3efe482d8
--- /dev/null
+++ b/spec/models/form/sales/subsections/shared_ownership_staircasing_transaction_spec.rb
@@ -0,0 +1,85 @@
+require "rails_helper"
+
+RSpec.describe Form::Sales::Subsections::SharedOwnershipStaircasingTransaction, type: :model do
+  subject(:shared_ownership_staircasing_transaction) { described_class.new(nil, nil, section) }
+
+  let(:form) { instance_double(Form, start_year_2026_or_later?: false) }
+  let(:section) { instance_double(Form::Sales::Sections::SaleInformation, form:) }
+
+  it "has correct section" do
+    expect(shared_ownership_staircasing_transaction.section).to eq(section)
+  end
+
+  it "has the correct depends_on" do
+    expect(shared_ownership_staircasing_transaction.depends_on).to eq([{ "ownershipsch" => 1, "setup_completed?" => true, "staircase" => 1 }])
+  end
+
+  it "has the correct id" do
+    expect(shared_ownership_staircasing_transaction.id).to eq("shared_ownership_staircasing_transaction")
+  end
+
+  it "has the correct label" do
+    expect(shared_ownership_staircasing_transaction.label).to eq("Shared ownership - staircasing transaction")
+  end
+
+  it "has the correct copy key" do
+    expect(shared_ownership_staircasing_transaction.copy_key).to eq("sale_information")
+  end
+
+  context "when the start year is 2025" do
+    let(:form) { instance_double(Form, start_year_2025_or_later?: true, start_year_2026_or_later?: false, start_date: Time.utc(2025, 4, 1)) }
+
+    it "has correct pages" do
+      expect(shared_ownership_staircasing_transaction.pages.map(&:id)).to eq(
+        %w[
+          about_staircasing_joint_purchase
+          about_staircasing_not_joint_purchase
+          staircase_sale
+          staircase_bought_value_check
+          staircase_owned_value_check_joint_purchase
+          staircase_owned_value_check_not_joint_purchase
+          staircase_first_time
+          staircase_previous
+          staircase_initial_date
+          value_shared_ownership_staircase
+          about_price_shared_ownership_value_check_staircasing
+          staircase_equity
+          shared_ownership_equity_value_check_staircasing
+          staircase_mortgage_used_shared_ownership
+          monthly_rent_staircasing_owned
+          monthly_rent_staircasing
+          monthly_charges_shared_ownership_value_check
+        ],
+      )
+    end
+  end
+
+  context "when the start year is 2026" do
+    let(:form) { instance_double(Form, start_year_2025_or_later?: true, start_year_2026_or_later?: true, start_date: Time.utc(2026, 4, 1)) }
+
+    it "has correct pages" do
+      expect(shared_ownership_staircasing_transaction.pages.map(&:id)).to eq(
+        %w[
+          about_staircasing_joint_purchase
+          about_staircasing_not_joint_purchase
+          staircase_sale
+          staircase_bought_value_check
+          staircase_owned_value_check_joint_purchase
+          staircase_owned_value_check_not_joint_purchase
+          staircase_first_time
+          staircase_previous
+          staircase_initial_date
+          value_shared_ownership_staircase
+          about_price_shared_ownership_value_check_staircasing
+          staircase_equity
+          shared_ownership_equity_value_check_staircasing
+          staircase_mortgage_used_shared_ownership
+          monthly_rent_staircasing_owned
+          monthly_rent_staircasing
+          service_charge_staircasing
+          monthly_charges_shared_ownership_value_check
+        ],
+      )
+    end
+  end
+end