diff --git a/app/controllers/form_controller.rb b/app/controllers/form_controller.rb
index 368af3bab..17fd9af77 100644
--- a/app/controllers/form_controller.rb
+++ b/app/controllers/form_controller.rb
@@ -102,12 +102,6 @@ private
         result[question.id] = question_params
       end
 
-      if %w[checkbox].include?(question.type) &&
-          !question.default_answer.nil? &&
-          question.answer_keys_without_dividers.all? { |answer_key| result[answer_key] != 1 }
-        result[question.default_answer] = 1
-      end
-
       if question.id == "owning_organisation_id"
         owning_organisation = result["owning_organisation_id"].present? ? Organisation.find(result["owning_organisation_id"]) : nil
         if current_user.support? && @log.managing_organisation.blank? && owning_organisation&.managing_agents&.empty?
@@ -235,8 +229,6 @@ private
   end
 
   def question_missing_response?(responses_for_page, question)
-    return unless question.default_answer.nil?
-
     if %w[checkbox validation_override].include?(question.type)
       answered = question.answer_keys_without_dividers.map do |option|
         session["fields"][option] = @log[option] = params[@log.model_name.param_key][question.id].include?(option) ? 1 : 0
diff --git a/app/models/derived_variables/sales_log_variables.rb b/app/models/derived_variables/sales_log_variables.rb
index ec8d21b30..4fd98319f 100644
--- a/app/models/derived_variables/sales_log_variables.rb
+++ b/app/models/derived_variables/sales_log_variables.rb
@@ -4,6 +4,7 @@ module DerivedVariables::SalesLogVariables
   def set_derived_fields!
     reset_invalidated_derived_values!(DEPENDENCIES)
 
+    self.pregblank = 1 if self.no_buyer_organisation?
     self.ethnic = 17 if ethnic_refused?
     self.mscharge = nil if no_monthly_leasehold_charges?
     if exdate.present?
diff --git a/app/models/form/question.rb b/app/models/form/question.rb
index 3bea2013a..391771ad9 100644
--- a/app/models/form/question.rb
+++ b/app/models/form/question.rb
@@ -6,7 +6,7 @@ class Form::Question
                 :top_guidance_partial, :bottom_guidance_partial, :prefix, :suffix,
                 :requires_js, :fields_added, :derived, :check_answers_card_number,
                 :unresolved_hint_text, :question_number, :hide_question_number_on_page,
-                :plain_label, :error_label, :default_answer
+                :plain_label, :error_label
 
   def initialize(id, hsh, page)
     @id = id
@@ -42,7 +42,6 @@ class Form::Question
       @plain_label = hsh["plain_label"]
       @error_label = hsh["error_label"]
       @disable_clearing_if_not_routed_or_dynamic_answer_options = hsh["disable_clearing_if_not_routed_or_dynamic_answer_options"]
-      @default_answer = hsh["default_answer"]
     end
   end
 
diff --git a/app/models/form/sales/questions/buyers_organisations.rb b/app/models/form/sales/questions/buyers_organisations.rb
index 3faa33f67..9c1cdf0e1 100644
--- a/app/models/form/sales/questions/buyers_organisations.rb
+++ b/app/models/form/sales/questions/buyers_organisations.rb
@@ -7,7 +7,6 @@ class Form::Sales::Questions::BuyersOrganisations < ::Form::Question
     @type = "checkbox"
     @hint_text = "Select all that apply. This question is optional. If no options are applicable, leave the options blank, and select save and continue."
     @answer_options = ANSWER_OPTIONS
-    @default_answer = "pregblank"
     @question_number = 59
   end
 
diff --git a/app/models/sales_log.rb b/app/models/sales_log.rb
index b4eab2093..b17956b3a 100644
--- a/app/models/sales_log.rb
+++ b/app/models/sales_log.rb
@@ -78,7 +78,7 @@ class SalesLog < Log
     scope.pluck("ARRAY_AGG(id)")
   }
 
-  OPTIONAL_FIELDS = %w[purchid othtype].freeze
+  OPTIONAL_FIELDS = %w[purchid othtype buyers_organisations].freeze
   RETIREMENT_AGES = { "M" => 65, "F" => 60, "X" => 65 }.freeze
   DUPLICATE_LOG_ATTRIBUTES = %w[owning_organisation_id purchid saledate age1_known age1 sex1 ecstat1 postcode_full].freeze
 
@@ -394,6 +394,13 @@ class SalesLog < Log
     has_mscharge&.zero?
   end
 
+  def no_buyer_organisation?
+    pregyrha&.zero? &&
+      pregla&.zero? &&
+      pregghb&.zero? &&
+      pregother&.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/buyers_organisations_spec.rb b/spec/models/form/sales/questions/buyers_organisations_spec.rb
index 74ad964d5..b0c932acc 100644
--- a/spec/models/form/sales/questions/buyers_organisations_spec.rb
+++ b/spec/models/form/sales/questions/buyers_organisations_spec.rb
@@ -35,10 +35,6 @@ RSpec.describe Form::Sales::Questions::BuyersOrganisations, type: :model do
     expect(question.hint_text).to eq("Select all that apply. This question is optional. If no options are applicable, leave the options blank, and select save and continue.")
   end
 
-  it "has the correct default" do
-    expect(question.default_answer).to eq("pregblank")
-  end
-
   it "has the correct answer_options" do
     expect(question.answer_options).to eq(
       {
diff --git a/spec/models/sales_log_spec.rb b/spec/models/sales_log_spec.rb
index 00792b0bd..9c6810963 100644
--- a/spec/models/sales_log_spec.rb
+++ b/spec/models/sales_log_spec.rb
@@ -596,6 +596,22 @@ RSpec.describe SalesLog, type: :model do
         expect { sales_log.update!(nationality_all_buyer2_group: nil) }.not_to change(sales_log, :nationality_all_buyer2)
       end
     end
+
+    it "sets pregblank field when no buyer organisation is selected" do
+      expect { sales_log.update!(
+        pregyrha: 0,
+        pregla: 0,
+        pregghb: 0,
+        pregother: 0) }
+        .to change(sales_log, :pregblank).to 1
+    end
+
+    %i[pregyrha pregla pregghb pregother].each do |field|
+      it "does not set pregblank field when #{field} is selected" do
+        expect { sales_log.update!({ field => 1, })}
+          .not_to change(sales_log, :pregblank)
+      end
+    end
   end
 
   context "when saving addresses" do