diff --git a/src/Message/AuthorizeRequest.php b/src/Message/AuthorizeRequest.php
index af3bdc2..ff6271b 100644
--- a/src/Message/AuthorizeRequest.php
+++ b/src/Message/AuthorizeRequest.php
@@ -99,7 +99,9 @@ protected function getXmlString()
             $billingDetails->addChild('street', $card->getBillingAddress1());
             $billingDetails->addChild('street2', $card->getBillingAddress2());
             $billingDetails->addChild('city', $card->getBillingCity());
-            $billingDetails->addChild('state', $card->getBillingState());
+            if ($card->getBillingCountry() === 'US') {
+                $billingDetails->addChild('state', $card->getBillingState());
+            }
             $billingDetails->addChild('country', $card->getBillingCountry());
             $billingDetails->addChild('zip', $card->getBillingPostcode());
             $billingDetails->addChild('phone', $card->getBillingPhone());
@@ -112,7 +114,9 @@ protected function getXmlString()
             $shippingDetails->addChild('street', $card->getShippingAddress1());
             $shippingDetails->addChild('street2', $card->getShippingAddress2());
             $shippingDetails->addChild('city', $card->getShippingCity());
-            $shippingDetails->addChild('state', $card->getShippingState());
+            if ($card->getShippingCountry() === 'US') {
+                $shippingDetails->addChild('state', $card->getShippingState());
+            }
             $shippingDetails->addChild('country', $card->getShippingCountry());
             $shippingDetails->addChild('zip', $card->getShippingPostcode());
             $shippingDetails->addChild('phone', $card->getShippingPhone());