The purchase order reference is a conditional element. If the Buyer has issued a purchase order it should be referenced by providing its identifier in the resulting invoice, otherwise you should use the BuyerReference element.

If the purchase order is referenced at the invoice header level, the document reference element on line level can be used to state the relevant line numbers in the order.

A sales order is issued by the Supplier, confirming the sale of specified products and may be provided in the invoice. In the invoice, both a purchase order and a sales order reference can be given, but be aware that an invoice instance cannot reference a sales order without providing the corresponding purchase order reference.

You can specify it at the Document or Line level.

Elements

Document level

Use the OrderReference element to specify this on the Document level:

Line level

Use the OrderLineReference element to specify this information on the Line level:

Country-Specific configurations

• Netherlands: Order Line References

Example

<Invoice>
    <!-- code omitted for clarity -->
    <cac:OrderReference>
        <cbc:ID>PO-11223344</cbc:ID>
        <cbc:SalesOrderID>SO-123456</cbc:SalesOrderID>
        <cbc:IssueDate>2024-08-30</cbc:IssueDate>
    </cac:OrderReference>    
    <!-- code omitted for clarity -->
</Invoice>