diff --git a/app/models/validations/sales/setup_validations.rb b/app/models/validations/sales/setup_validations.rb
index bb99f02ed..d52af8f9b 100644
--- a/app/models/validations/sales/setup_validations.rb
+++ b/app/models/validations/sales/setup_validations.rb
@@ -37,7 +37,7 @@ module Validations::Sales::SetupValidations
     if absorbing_owning_organisation_inactive?(record)
       record.errors.add :saledate, I18n.t("validations.setup.saledate.invalid_absorbing_organisations_saledate",
                                           owning_organisation: record.owning_organisation.name,
-                                          owning_organisation_available_from: record.owning_organisation.created_at.to_formatted_s(:govuk_date))
+                                          owning_organisation_available_from: record.owning_organisation.available_from.to_formatted_s(:govuk_date))
     end
   end
 
@@ -50,10 +50,10 @@ module Validations::Sales::SetupValidations
                                                           owning_organisation: record.owning_organisation.name,
                                                           owning_organisation_merge_date: record.owning_organisation.merge_date.to_formatted_s(:govuk_date),
                                                           owning_absorbing_organisation: record.owning_organisation.absorbing_organisation.name)
-      elsif record.owning_organisation&.absorbed_organisations.present? && record.owning_organisation.created_at.to_date > record.saledate.to_date
+      elsif record.owning_organisation&.absorbed_organisations.present? && record.owning_organisation.available_from.present? && record.owning_organisation.available_from.to_date > record.saledate.to_date
         record.errors.add :owning_organisation_id, I18n.t("validations.setup.owning_organisation.inactive_absorbing_organisation_sales",
                                                           owning_organisation: record.owning_organisation.name,
-                                                          owning_organisation_available_from: record.owning_organisation.created_at.to_formatted_s(:govuk_date))
+                                                          owning_organisation_available_from: record.owning_organisation.available_from.to_formatted_s(:govuk_date))
       end
     end
   end
@@ -104,6 +104,6 @@ private
   end
 
   def absorbing_owning_organisation_inactive?(record)
-    record.owning_organisation&.absorbed_organisations.present? && record.owning_organisation.created_at.to_date > record.saledate.to_date
+    record.owning_organisation&.absorbed_organisations.present? && record.owning_organisation.available_from.present? && record.owning_organisation.available_from.to_date > record.saledate.to_date
   end
 end
diff --git a/spec/models/validations/sales/setup_validations_spec.rb b/spec/models/validations/sales/setup_validations_spec.rb
index f7f01eaf7..526024ae3 100644
--- a/spec/models/validations/sales/setup_validations_spec.rb
+++ b/spec/models/validations/sales/setup_validations_spec.rb
@@ -188,7 +188,7 @@ RSpec.describe Validations::Sales::SetupValidations do
 
   describe "#validate_merged_organisations_saledate" do
     let(:record) { build(:sales_log) }
-    let(:absorbing_organisation) { create(:organisation, created_at: Time.zone.local(2023, 2, 1), name: "Absorbing org") }
+    let(:absorbing_organisation) { create(:organisation, created_at: Time.zone.local(2023, 2, 1), available_from: Time.zone.local(2023, 2, 1), name: "Absorbing org") }
     let(:merged_organisation) { create(:organisation, name: "Merged org") }
 
     around do |example|
@@ -218,19 +218,27 @@ RSpec.describe Validations::Sales::SetupValidations do
     end
 
     context "and owning organisation is not yet active during the saledate" do
-      it "does not allow saledate before absorbing organisation has been created" do
+      it "does not allow saledate before absorbing organisation has become available" do
         record.saledate = Time.zone.local(2023, 1, 1)
         record.owning_organisation_id = absorbing_organisation.id
         setup_validator.validate_merged_organisations_saledate(record)
         expect(record.errors["saledate"]).to include(match "Enter a date when the owning organisation was active. Absorbing org became active on 1 February 2023.")
       end
 
-      it "allows saledate after absorbing organisation has been created" do
+      it "allows saledate after absorbing organisation has become available" do
         record.saledate = Time.zone.local(2023, 2, 2)
         record.owning_organisation_id = absorbing_organisation.id
         setup_validator.validate_merged_organisations_saledate(record)
         expect(record.errors["saledate"]).to be_empty
       end
+
+      it "allows saledate if available from is not given" do
+        record.saledate = Time.zone.local(2023, 1, 1)
+        absorbing_organisation.update!(available_from: nil)
+        record.owning_organisation_id = absorbing_organisation.id
+        setup_validator.validate_merged_organisations_saledate(record)
+        expect(record.errors["saledate"]).to be_empty
+      end
     end
   end
 
@@ -238,7 +246,7 @@ RSpec.describe Validations::Sales::SetupValidations do
     let(:record) { build(:sales_log) }
 
     context "when organisations are merged" do
-      let(:absorbing_organisation) { create(:organisation, created_at: Time.zone.local(2023, 2, 1), name: "Absorbing org") }
+      let(:absorbing_organisation) { create(:organisation, created_at: Time.zone.local(2023, 2, 1), available_from: Time.zone.local(2023, 2, 1), name: "Absorbing org") }
       let(:merged_organisation) { create(:organisation, name: "Merged org") }
 
       around do |example|
@@ -265,19 +273,27 @@ RSpec.describe Validations::Sales::SetupValidations do
       end
 
       context "and owning organisation is not yet active during the saledate" do
-        it "does not allow absorbing organisation before it had been created" do
+        it "does not allow absorbing organisation before it has become available" do
           record.saledate = Time.zone.local(2023, 1, 1)
           record.owning_organisation_id = absorbing_organisation.id
           setup_validator.validate_organisation(record)
           expect(record.errors["owning_organisation_id"]).to include(match "The owning organisation must be active on the sale completion date. Absorbing org became active on 1 February 2023.")
         end
 
-        it "allows absorbing organisation after it has been created" do
+        it "allows absorbing organisation after it has become available" do
           record.saledate = Time.zone.local(2023, 2, 2)
           record.owning_organisation_id = absorbing_organisation.id
           setup_validator.validate_organisation(record)
           expect(record.errors["owning_organisation_id"]).to be_empty
         end
+
+        it "allows absorbing organisation if available from is not given" do
+          record.saledate = Time.zone.local(2023, 1, 1)
+          absorbing_organisation.update!(available_from: nil)
+          record.owning_organisation_id = absorbing_organisation.id
+          setup_validator.validate_organisation(record)
+          expect(record.errors["owning_organisation_id"]).to be_empty
+        end
       end
     end
   end