diff --git a/app/controllers/repp/v1/domains/contacts_controller.rb b/app/controllers/repp/v1/domains/contacts_controller.rb
index a90a2d27a0..53f8559d93 100644
--- a/app/controllers/repp/v1/domains/contacts_controller.rb
+++ b/app/controllers/repp/v1/domains/contacts_controller.rb
@@ -41,9 +41,7 @@ def destroy
         def cta(action = 'add')
           params[:contacts].each { |c| c[:action] = action }
           action = Actions::DomainUpdate.new(@domain, contact_create_params, false)
-          # rubocop:disable Style/AndOr
           handle_errors(@domain) and return unless action.call
-          # rubocop:enable Style/AndOr
 
           render_success(data: { domain: { name: @domain.name } })
         end
diff --git a/app/controllers/repp/v1/domains_controller.rb b/app/controllers/repp/v1/domains_controller.rb
index 49c91e133e..c72c83882f 100644
--- a/app/controllers/repp/v1/domains_controller.rb
+++ b/app/controllers/repp/v1/domains_controller.rb
@@ -94,10 +94,6 @@ def create
           param :verified, [true, false, 'true', 'false'], required: false,
                                                            desc: 'Registrant change is already verified'
         end
-        param :contacts, Array, required: false, desc: 'Array of linked contacts' do
-          param :code, String, required: true, desc: 'Contact code'
-          param :type, String, required: true, desc: 'Role of contact (admin/tech)'
-        end
         param :transfer_code, String, required: false, desc: 'New authorization code'
       end
       def update
diff --git a/app/interactions/actions/domain_update.rb b/app/interactions/actions/domain_update.rb
index ff6eccce2d..ca2814fdf6 100644
--- a/app/interactions/actions/domain_update.rb
+++ b/app/interactions/actions/domain_update.rb
@@ -30,7 +30,7 @@ def assign_relational_modifications
     end
 
     def check_for_same_contacts(contacts, contact_type)
-      return unless contacts.uniq.count != contacts.count
+      return if contacts.uniq.count == contacts.count
 
       domain.add_epp_error('2306', contact_type, nil, %i[domain_contacts invalid])
     end
@@ -194,22 +194,33 @@ def gather_domain_contacts(contacts, admin: true)
     def contact_for_action(action:, method:, code:)
       contact = Epp::Contact.find_by(code: code)
       return contact if action == 'add' || !contact
-      return domain.admin_domain_contacts.find_by(contact_id: contact.id) if method == 'admin'
 
-      domain.tech_domain_contacts.find_by(contact_id: contact.id)
+      existing_contact(id: contact.id, admin: method == 'admin')
     end
 
-    def assign_contact(obj, add: false, admin: true, code:)
+    def existing_contact(id:, admin: true)
+      return domain.admin_domain_contacts.find_by(contact_id: id) if admin
+
+      domain.tech_domain_contacts.find_by(contact_id: id)
+    end
+
+    def assign_contact(obj, code:, add: false, admin: true)
       if obj.blank?
         domain.add_epp_error('2303', 'contact', code, %i[domain_contacts not_found])
       elsif obj.try(:org?) && admin && add
         domain.add_epp_error('2306', 'contact', code,
                              %i[domain_contacts admin_contact_can_be_only_private_person])
       else
-        add ? { contact_id: obj.id, contact_code: obj.code } : { id: obj.id, _destroy: 1 }
+        assigned_contact_hash(obj, add, admin)
       end
     end
 
+    def assigned_contact_hash(obj, add, admin)
+      return if !existing_contact(id: obj.id, admin: admin).nil? && add
+
+      add ? { contact_id: obj.id, contact_code: obj.code } : { id: obj.id, _destroy: 1 }
+    end
+
     def assign_requested_statuses
       return unless params[:statuses]