diff --git a/app/models/derived_variables/sales_log_variables.rb b/app/models/derived_variables/sales_log_variables.rb
index 56d687f59..1e7489015 100644
--- a/app/models/derived_variables/sales_log_variables.rb
+++ b/app/models/derived_variables/sales_log_variables.rb
@@ -1,6 +1,7 @@
 module DerivedVariables::SalesLogVariables
   def set_derived_fields!
     self.ethnic = 17 if ethnic_refused?
+    self.mscharge = nil if monthly_leasehold_charges_unknown?
     if exdate.present?
       self.exday = exdate.day
       self.exmonth = exdate.month
@@ -12,9 +13,6 @@ module DerivedVariables::SalesLogVariables
       self.hoyear = hodate.year
     end
     self.deposit = value if outright_sale? && mortgage_not_used?
-    if mscharge_known.present? && mscharge_known.zero?
-      self.mscharge = 0
-    end
     if mortgage_not_used?
       self.mortgage = 0
     end
diff --git a/app/models/form/sales/questions/leasehold_charges_known.rb b/app/models/form/sales/questions/leasehold_charges_known.rb
index a800690e4..92370a3ac 100644
--- a/app/models/form/sales/questions/leasehold_charges_known.rb
+++ b/app/models/form/sales/questions/leasehold_charges_known.rb
@@ -3,7 +3,7 @@ class Form::Sales::Questions::LeaseholdChargesKnown < ::Form::Question
     super(id, hsh, subsection)
     @id = "mscharge_known"
     @check_answer_label = "Monthly leasehold charges known?"
-    @header = "Does the property have any monthly leasehold charges?"
+    @header = "Do you know the monthly leasehold charges for the property?"
     @hint_text = "For example, service and management charges"
     @type = "radio"
     @answer_options = ANSWER_OPTIONS
diff --git a/app/models/sales_log.rb b/app/models/sales_log.rb
index 2a6e1a6d3..721209ee9 100644
--- a/app/models/sales_log.rb
+++ b/app/models/sales_log.rb
@@ -299,6 +299,10 @@ class SalesLog < Log
     companybuy == 1
   end
 
+  def monthly_leasehold_charges_unknown?
+    mscharge_known&.zero?
+  end
+
   def buyers_age_for_old_persons_shared_ownership_invalid?
     return unless old_persons_shared_ownership?
 
diff --git a/spec/models/form/sales/questions/leasehold_charges_known_spec.rb b/spec/models/form/sales/questions/leasehold_charges_known_spec.rb
index 64cd08f33..b8d191d3b 100644
--- a/spec/models/form/sales/questions/leasehold_charges_known_spec.rb
+++ b/spec/models/form/sales/questions/leasehold_charges_known_spec.rb
@@ -16,7 +16,7 @@ RSpec.describe Form::Sales::Questions::LeaseholdChargesKnown, type: :model do
   end
 
   it "has the correct header" do
-    expect(question.header).to eq("Does the property have any monthly leasehold charges?")
+    expect(question.header).to eq("Do you know the monthly leasehold charges for the property?")
   end
 
   it "has the correct check_answer_label" do