diff --git a/app/services/merge/merge_organisations_service.rb b/app/services/merge/merge_organisations_service.rb
index bcaad85a6..40749b54c 100644
--- a/app/services/merge/merge_organisations_service.rb
+++ b/app/services/merge/merge_organisations_service.rb
@@ -62,7 +62,7 @@ private
   def merge_users(merging_organisation)
     users_to_merge = users_to_merge(merging_organisation)
     @merged_users[merging_organisation.name] = users_to_merge.map { |user| { name: user.name, email: user.email } }
-    users_to_merge.update_all(organisation_id: @absorbing_organisation.id)
+    users_to_merge.update_all(organisation_id: @absorbing_organisation.id, values_updated_at: Time.zone.now)
   end
 
   def merge_schemes_and_locations(merging_organisation)
diff --git a/db/migrate/20250305092900_add_values_updated_at_to_user.rb b/db/migrate/20250305092900_add_values_updated_at_to_user.rb
new file mode 100644
index 000000000..8ebe67af4
--- /dev/null
+++ b/db/migrate/20250305092900_add_values_updated_at_to_user.rb
@@ -0,0 +1,5 @@
+class AddValuesUpdatedAtToUser < ActiveRecord::Migration[7.2]
+  def change
+    add_column :users, :values_updated_at, :datetime
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 20a836eed..4f85d606c 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.2].define(version: 2025_02_25_180643) do
+ActiveRecord::Schema[7.2].define(version: 2025_03_05_092900) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
 
@@ -852,6 +852,7 @@ ActiveRecord::Schema[7.2].define(version: 2025_02_25_180643) do
     t.boolean "reactivate_with_organisation"
     t.datetime "discarded_at"
     t.string "phone_extension"
+    t.datetime "values_updated_at"
     t.index ["confirmation_token"], name: "index_users_on_confirmation_token", unique: true
     t.index ["email"], name: "index_users_on_email", unique: true
     t.index ["encrypted_otp_secret_key"], name: "index_users_on_encrypted_otp_secret_key", unique: true
diff --git a/spec/services/merge/merge_organisations_service_spec.rb b/spec/services/merge/merge_organisations_service_spec.rb
index f20e16a16..9355a757a 100644
--- a/spec/services/merge/merge_organisations_service_spec.rb
+++ b/spec/services/merge/merge_organisations_service_spec.rb
@@ -31,10 +31,12 @@ RSpec.describe Merge::MergeOrganisationsService do
         expect(Rails.logger).to receive(:info).with("\t#{merging_organisation.data_protection_officers.first.name} (#{merging_organisation.data_protection_officers.first.email})")
         expect(Rails.logger).to receive(:info).with("\tfake name (fake@email.com)")
         expect(Rails.logger).to receive(:info).with("New schemes from fake org:")
+        expect(merging_organisation_user.values_updated_at).to be_nil
         merge_organisations_service.call
 
         merging_organisation_user.reload
         expect(merging_organisation_user.organisation).to eq(absorbing_organisation)
+        expect(merging_organisation_user.values_updated_at).not_to be_nil
       end
 
       it "sets merge date on merged organisation" do