diff --git a/app/models/epp/domain.rb b/app/models/epp/domain.rb
index 732328337..1d71863ee 100644
--- a/app/models/epp/domain.rb
+++ b/app/models/epp/domain.rb
@@ -489,6 +489,15 @@ class Epp::Domain < Domain
 
     # at[:statuses] += at_add[:domain_statuses_attributes]
 
+    if registrant_id && registrant.code == frame.css('registrant')
+
+      throw :epp_error, {
+        code: '2305',
+        msg: I18n.t(:contact_already_associated_with_the_domain)
+      }
+
+    end
+
     if errors.empty? && verify &&
        Setting.request_confrimation_on_registrant_change_enabled &&
        frame.css('registrant').present? &&
diff --git a/config/locales/en.yml b/config/locales/en.yml
index db0ca37ce..26822ab0c 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -935,4 +935,5 @@ en:
   add_reserved_domain: 'Add domain to reserved list'
   add_blocked_domain: 'Add domain to blocked list'
   edit_pw: 'Edit Pw'
-  optional: 'Optional'
\ No newline at end of file
+  optional: 'Optional'  
+  contact_already_associated_with_the_domain: 'Object association prohibits operation, contact already associated with the domain'