diff --git a/app/models/validations/sales/sale_information_validations.rb b/app/models/validations/sales/sale_information_validations.rb
index 32bf2a716..7cd24183c 100644
--- a/app/models/validations/sales/sale_information_validations.rb
+++ b/app/models/validations/sales/sale_information_validations.rb
@@ -42,7 +42,7 @@ module Validations::Sales::SaleInformationValidations
       record.errors.add :initialpurchase, I18n.t("validations.sales.sale_information.initialpurchase.must_be_after_1980")
     end
 
-    if record.saledate.present? && record.initialpurchase > record.saledate
+    if record.saledate.present? && ((record.initialpurchase > record.saledate) || (record.initialpurchase == record.saledate && record.form.start_year_2026_or_later?))
       record.errors.add :initialpurchase, I18n.t("validations.sales.sale_information.initialpurchase.must_be_before_saledate")
       record.errors.add :saledate, :skip_bu_error, message: I18n.t("validations.sales.sale_information.saledate.must_be_after_initial_purchase_date")
     end
@@ -55,11 +55,11 @@ module Validations::Sales::SaleInformationValidations
       record.errors.add :lasttransaction, I18n.t("validations.sales.sale_information.lasttransaction.must_be_after_1980")
     end
 
-    if record.saledate.present? && record.lasttransaction > record.saledate
+    if record.saledate.present? && ((record.lasttransaction > record.saledate) || (record.lasttransaction == record.saledate && record.form.start_year_2026_or_later?))
       record.errors.add :lasttransaction, I18n.t("validations.sales.sale_information.lasttransaction.must_be_before_saledate")
       record.errors.add :saledate, :skip_bu_error, message: I18n.t("validations.sales.sale_information.saledate.must_be_after_last_transaction_date")
     end
-    if record.initialpurchase.present? && record.lasttransaction < record.initialpurchase
+    if record.initialpurchase.present? && ((record.lasttransaction < record.initialpurchase) || (record.lasttransaction == record.initialpurchase && record.form.start_year_2026_or_later?))
       record.errors.add :initialpurchase, I18n.t("validations.sales.sale_information.initialpurchase.must_be_before_last_transaction")
       record.errors.add :lasttransaction, I18n.t("validations.sales.sale_information.lasttransaction.must_be_after_initial_purchase")
     end
diff --git a/lib/tasks/fix_sales_logs_with_invalid_initialpurchase_lasttransaction.rake b/lib/tasks/fix_sales_logs_with_invalid_initialpurchase_lasttransaction.rake
new file mode 100644
index 000000000..44475a46f
--- /dev/null
+++ b/lib/tasks/fix_sales_logs_with_invalid_initialpurchase_lasttransaction.rake
@@ -0,0 +1,13 @@
+desc "We tightened the validation in 2026 between initial purchase date, last transaction date and sale date so that no two can be equal and initial purchase date < last transaction date < sale date. To avoid invalid logs we clear lasttransaction if it equals saledate and if initialpurchase = lasttransaction we clear both"
+task fix_sales_logs_with_invalid_initialpurchase_lasttransaction: :environment do
+  lasttransaction_equal_saledate_logs = SalesLog.filter_by_year_or_later(2026).where("lasttransaction = saledate")
+  initial_purchase_equal_lasttransaction_logs = SalesLog.filter_by_year_or_later(2026).where("initialpurchase = lasttransaction")
+
+  puts "Updating #{lasttransaction_equal_saledate_logs.count} logs where lasttransaction = saledate, #{lasttransaction_equal_saledate_logs.map(&:id)}"
+  lasttransaction_equal_saledate_logs.update!(lasttransaction: nil)
+
+  puts "Updating #{initial_purchase_equal_lasttransaction_logs.count} logs where initialpurchase = lasttransaction, #{initial_purchase_equal_lasttransaction_logs.map(&:id)}"
+  initial_purchase_equal_lasttransaction_logs.update!(initialpurchase: nil, lasttransaction: nil)
+
+  puts "Done"
+end
diff --git a/spec/models/validations/sales/sale_information_validations_spec.rb b/spec/models/validations/sales/sale_information_validations_spec.rb
index 8d4eb4cea..04f71b198 100644
--- a/spec/models/validations/sales/sale_information_validations_spec.rb
+++ b/spec/models/validations/sales/sale_information_validations_spec.rb
@@ -252,12 +252,27 @@ RSpec.describe Validations::Sales::SaleInformationValidations do
     end
 
     context "when initial purchase date == saledate" do
-      let(:record) { build(:sales_log, initialpurchase: current_collection_start_date, saledate: current_collection_start_date) }
+      let(:record) { build(:sales_log, initialpurchase: collection_start_date_for_year(start_year), saledate: collection_start_date_for_year(start_year)) }
 
-      it "does not add an error" do
-        sale_information_validator.validate_staircasing_initial_purchase_date(record)
+      context "and 2025", metadata: { year: 25 } do
+        let(:start_year) { 2025 }
 
-        expect(record.errors[:initialpurchase]).not_to be_present
+        it "does not add an error" do
+          sale_information_validator.validate_staircasing_initial_purchase_date(record)
+
+          expect(record.errors[:lasttransaction]).not_to be_present
+        end
+      end
+
+      context "and 2026", metadata: { year: 26 } do
+        let(:start_year) { 2026 }
+
+        it "adds error" do
+          sale_information_validator.validate_staircasing_initial_purchase_date(record)
+
+          expect(record.errors[:initialpurchase]).to eq([I18n.t("validations.sales.sale_information.initialpurchase.must_be_before_saledate")])
+          expect(record.errors[:saledate]).to eq([I18n.t("validations.sales.sale_information.saledate.must_be_after_initial_purchase_date")])
+        end
       end
     end
   end
@@ -315,12 +330,27 @@ RSpec.describe Validations::Sales::SaleInformationValidations do
     end
 
     context "when last transaction date == saledate" do
-      let(:record) { build(:sales_log, lasttransaction: current_collection_start_date, saledate: current_collection_start_date) }
+      let(:record) { build(:sales_log, lasttransaction: collection_start_date_for_year(start_year), saledate: collection_start_date_for_year(start_year)) }
 
-      it "does not add an error" do
-        sale_information_validator.validate_staircasing_last_transaction_date(record)
+      context "and 2025", metadata: { year: 25 } do
+        let(:start_year) { 2025 }
 
-        expect(record.errors[:lasttransaction]).not_to be_present
+        it "does not add an error" do
+          sale_information_validator.validate_staircasing_last_transaction_date(record)
+
+          expect(record.errors[:lasttransaction]).not_to be_present
+        end
+      end
+
+      context "and 2026", metadata: { year: 26 } do
+        let(:start_year) { 2026 }
+
+        it "adds error" do
+          sale_information_validator.validate_staircasing_last_transaction_date(record)
+
+          expect(record.errors[:lasttransaction]).to eq([I18n.t("validations.sales.sale_information.lasttransaction.must_be_before_saledate")])
+          expect(record.errors[:saledate]).to eq([I18n.t("validations.sales.sale_information.saledate.must_be_after_last_transaction_date")])
+        end
       end
     end
 
@@ -346,12 +376,27 @@ RSpec.describe Validations::Sales::SaleInformationValidations do
     end
 
     context "when last transaction date == initial purchase date" do
-      let(:record) { build(:sales_log, lasttransaction: current_collection_start_date, initialpurchase: current_collection_start_date) }
+      let(:record) { build(:sales_log, lasttransaction: collection_start_date_for_year(start_year), initialpurchase: collection_start_date_for_year(start_year), saledate: collection_start_date_for_year(start_year) + 1.day) }
 
-      it "does not add an error" do
-        sale_information_validator.validate_staircasing_last_transaction_date(record)
+      context "and 2025", metadata: { year: 25 } do
+        let(:start_year) { 2025 }
 
-        expect(record.errors[:lasttransaction]).not_to be_present
+        it "does not add an error" do
+          sale_information_validator.validate_staircasing_last_transaction_date(record)
+
+          expect(record.errors[:lasttransaction]).not_to be_present
+        end
+      end
+
+      context "and 2026", metadata: { year: 26 } do
+        let(:start_year) { 2026 }
+
+        it "adds error" do
+          sale_information_validator.validate_staircasing_last_transaction_date(record)
+
+          expect(record.errors[:lasttransaction]).to eq([I18n.t("validations.sales.sale_information.lasttransaction.must_be_after_initial_purchase")])
+          expect(record.errors[:initialpurchase]).to eq([I18n.t("validations.sales.sale_information.initialpurchase.must_be_before_last_transaction")])
+        end
       end
     end
   end