diff --git a/src/application/models/Customers_model.php b/src/application/models/Customers_model.php
index e6cb88ac..39bd44a0 100644
--- a/src/application/models/Customers_model.php
+++ b/src/application/models/Customers_model.php
@@ -68,7 +68,7 @@ class Customers_Model extends CI_Model {
      */
     public function exists($customer)
     {
-        if ( ! isset($customer['email']))
+        if (empty($customer['email']))
         {
             throw new Exception('Customer\'s email is not provided.');
         }
@@ -163,7 +163,7 @@ class Customers_Model extends CI_Model {
      */
     public function find_record_id($customer)
     {
-        if ( ! isset($customer['email']))
+        if (empty($customer['email']))
         {
             throw new Exception('Customer\'s email was not provided: '
                 . print_r($customer, TRUE));
@@ -216,9 +216,10 @@ class Customers_Model extends CI_Model {
         $phone_number_required = $query->num_rows() > 0 ? $query->row() === '1' : false;
 
         // Validate required fields
-        if ( ! isset($customer['last_name'])
-            || ! isset($customer['email'])
-            || (!isset($customer['phone_number']) && $phone_number_required))
+        if ( empty($customer['first_name'])
+            || empty($customer['last_name'])
+            || empty($customer['email'])
+            || (empty($customer['phone_number']) && $phone_number_required))
         {
             throw new Exception('Not all required fields are provided: '
                 . print_r($customer, TRUE));