diff --git a/README.md b/README.md
index a7bac42..f770969 100644
--- a/README.md
+++ b/README.md
@@ -16,7 +16,7 @@ The package is fairly simple. All you need to do is install this package via [co
 **Installation**
 1. `composer require qbil-software/read-soft-online`
 2. `require_once 'vendor/autoload.php';`
-3. `$client = new Client('insert_api_key_here');`
+3. `$client = new Qbil\ReadSoftOnline\Client('insert_api_key_here');`
 4. Authenticate using `$client->authenticate('rso username here', 'rso password here')`
 
 
diff --git a/src/Qbil/Models/Invoice.php b/src/Qbil/Models/Invoice.php
index 135f405..1e3de05 100644
--- a/src/Qbil/Models/Invoice.php
+++ b/src/Qbil/Models/Invoice.php
@@ -23,6 +23,7 @@ public function __construct(Document $document)
         $this->theirVatRegistration = $this->extract($document->HeaderFields, 'suppliervatregistrationnumber');
         $this->ourVatRegistration = $this->extract($document->HeaderFields, 'CustomerVATRegistrationNumber');
         $this->orderNumber = $this->extract($document->HeaderFields, 'invoiceordernumber');
+        $this->contract = $this->extract($document->HeaderFields, 'Inkoopcontract');
 
         foreach (array_column($this->extract($document->Tables, 'LineItem', 'TableRows'), 'ItemFields') as $line) {
             $invoiceLine = new InvoiceLine(
@@ -30,6 +31,7 @@ public function __construct(Document $document)
                 $this->extract($line, 'LIT_DeliveredQuantity'),
                 $this->extract($line, 'LIT_VatExcludedAmount'),
                 $this->extract($line, 'LIT_UnitPriceAmount'),
+                $this->extract($line, 'LIT_Inkoopcontract'),
                 $document->DocumentSubType
             );
 
@@ -48,6 +50,7 @@ public function __construct(Document $document)
     private $theirVatRegistration;
     private $ourVatRegistration;
     private $orderNumber;
+    private $contract;
     private $invoiceLines = [];
 
     public function addInvoiceLine(InvoiceLine $invoiceLine)
@@ -155,4 +158,12 @@ public function getOrder()
     {
         return $this->orderNumber;
     }
+
+    /**
+     * @return mixed
+     */
+    public function getContract()
+    {
+        return $this->contract;
+    }
 }
diff --git a/src/Qbil/Models/InvoiceLine.php b/src/Qbil/Models/InvoiceLine.php
index 3a0734f..c832c87 100644
--- a/src/Qbil/Models/InvoiceLine.php
+++ b/src/Qbil/Models/InvoiceLine.php
@@ -10,12 +10,13 @@
 
 class InvoiceLine
 {
-    public function __construct($order, $quantity, $amount, $price, $type, $allocatedInvoice = null)
+    public function __construct($order, $quantity, $amount, $price, $purchaseContract, $type, $allocatedInvoice = null)
     {
         $this->order = $order;
         $this->quantity = $quantity;
         $this->amount = $amount;
         $this->price = $price;
+        $this->purchaseContract = $purchaseContract;
         $this->type = $type;
         $this->allocatedInvoice = $allocatedInvoice;
     }
@@ -24,6 +25,7 @@ public function __construct($order, $quantity, $amount, $price, $type, $allocate
     private $quantity;
     private $amount;
     private $price;
+    private $purchaseContract;
     private $type;
     private $allocatedInvoice;
 
@@ -84,10 +86,18 @@ public function setType($type)
     }
 
     /**
-     * @param mixed $type
+     * @param $allocatedInvoice
      */
     public function setAllocatedInvoice($allocatedInvoice)
     {
         $this->allocatedInvoice = $allocatedInvoice;
     }
+
+    /**
+     * @return mixed
+     */
+    public function getPurchaseContract()
+    {
+        return $this->purchaseContract;
+    }
 }