diff --git a/src/Shipping.php b/src/Shipping.php
index fcaf9f5..a589c14 100644
--- a/src/Shipping.php
+++ b/src/Shipping.php
@@ -184,6 +184,10 @@ private function createConfirmRequest(
             $shipToNode->appendChild($xml->createElement('AttentionName', $shipment->getShipTo()->getAttentionName()));
         }
 
+        if ($shipment->getShipTo()->getTaxIdentificationNumber()) {
+            $shipToNode->appendChild($xml->createElement('TaxIdentificationNumber', $shipment->getShipTo()->getTaxIdentificationNumber()));
+        }
+
         if ($shipment->getShipTo()->getPhoneNumber()) {
             $shipToNode->appendChild($xml->createElement('PhoneNumber', $shipment->getShipTo()->getPhoneNumber()));
         }
@@ -241,6 +245,10 @@ private function createConfirmRequest(
                 $soldToNode->appendChild($xml->createElement('AttentionName', $shipment->getSoldTo()->getAttentionName()));
             }
 
+            if ($shipment->getSoldTo()->getTaxIdentificationNumber()) {
+                $soldToNode->appendChild($xml->createElement('TaxIdentificationNumber', $shipment->getSoldTo()->getTaxIdentificationNumber()));
+            }
+
             if ($shipment->getSoldTo()->getPhoneNumber()) {
                 $soldToNode->appendChild($xml->createElement('PhoneNumber', $shipment->getSoldTo()->getPhoneNumber()));
             }