diff --git a/README.md b/README.md
index 9af479a..ae6b475 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 **Objective**
 
-This project attempt to extract data from Openbravo to generate a JSON to submit
+This project attempts to extract data from Openbravo to generate a JSON to submit
 to the Banqup API of Unifiedpost.
 
 **Requirements**
diff --git a/extract_invoice.py b/extract_invoice.py
index 67c7be5..bb9de73 100644
--- a/extract_invoice.py
+++ b/extract_invoice.py
@@ -77,7 +77,12 @@ def extract_invoice(document):
 	    "currency_code": invoice['response']['data'][0]['currency$_identifier'],
 	    "client_id": banqup_client_id,
 	    "delivery_channel": preferred_channel,
-	    "invoice_lines": json.loads(lines_output)
+	    "invoice_lines": json.loads(lines_output),
+	    "po_number": "NA",
+	    "buyer_reference": "NA",
+	    "customer_reference": "NA",
+	    "supplier_reference": "NA",
+	    "contract_number": "NA"
 	})
 	#print(payload)