diff --git a/app/controllers/repp/v1/invoices_controller.rb b/app/controllers/repp/v1/invoices_controller.rb
index bd807e7b8..aff8e5841 100644
--- a/app/controllers/repp/v1/invoices_controller.rb
+++ b/app/controllers/repp/v1/invoices_controller.rb
@@ -37,8 +37,17 @@ module Repp
 
       api :post, '/repp/v1/invoices/:id/send_to_recipient'
       desc 'Send invoice pdf to recipient'
+      param :invoice, Hash, required: true, desc: 'Invoice data for sending to recipient' do
+        param :id, String, required: true, desc: 'Invoice id'
+        param :recipient, String, required: true, desc: 'Invoice receipient email'
+      end
       def send_to_recipient
         recipient = invoice_params[:recipient]
+        unless recipient.present?
+          handle_non_epp_errors(@invoice, 'Invoice recipient cannot be empty')
+          return
+        end
+
         InvoiceMailer.invoice_email(invoice: @invoice, recipient: recipient)
                      .deliver_now
         serializer = Serializers::Repp::Invoice.new(@invoice, simplify: true)
diff --git a/app/models/registrar.rb b/app/models/registrar.rb
index 3cd2da760..0ea0bfb13 100644
--- a/app/models/registrar.rb
+++ b/app/models/registrar.rb
@@ -39,7 +39,7 @@ class Registrar < ApplicationRecord
 
   alias_attribute :contact_email, :email
 
-  WHOIS_TRIGGERS = %w(name email phone street city state zip)
+  WHOIS_TRIGGERS = %w[name email phone street city state zip].freeze
 
   after_commit :update_whois_records
   def update_whois_records
diff --git a/app/models/user.rb b/app/models/user.rb
index 3bb8318c3..8ee0ea05c 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -13,7 +13,7 @@ class User < ApplicationRecord
 
   def self.from_omniauth(omniauth_hash)
     uid = omniauth_hash['uid']
-    identity_code = uid.slice(2..-1)
+    identity_code = uid&.slice(2..-1)
     # country_code = uid.slice(0..1)
 
     find_by(identity_code: identity_code, active: true)