diff --git a/src/Qbil/Models/InvoiceLine.php b/src/Qbil/Models/InvoiceLine.php
index 398617c..9138e5f 100644
--- a/src/Qbil/Models/InvoiceLine.php
+++ b/src/Qbil/Models/InvoiceLine.php
@@ -128,6 +128,14 @@ public function getPurchaseContract()
         return $this->purchaseContract;
     }
 
+    /**
+     * @return mixed
+     */
+    public function getVatCode()
+    {
+        return null;
+    }
+
     public function setAllocatedInvoice(string $allocatedInvoice)
     {
         $this->allocatedInvoice = $allocatedInvoice;
diff --git a/src/Qbil/Models/InvoiceLineInterface.php b/src/Qbil/Models/InvoiceLineInterface.php
index 47317e9..860c681 100644
--- a/src/Qbil/Models/InvoiceLineInterface.php
+++ b/src/Qbil/Models/InvoiceLineInterface.php
@@ -15,4 +15,5 @@ public function getType();
     public function getAllocatedInvoice();
     public function setAllocatedInvoice(string $allocatedInvoice);
     public function getPurchaseContract();
+    public function getVatCode();
 }