When a shopper checks out using a purchase order number, the Store API createOrder endpoint includes the purchase order number in the submitted order. The merchant can then issue an invoice for the amount owed. After receiving payment, the merchant should invoke the updateOrder endpoint to update the order.

You can optionally configure the Generic Payment webhook to send transaction data, including the purchase order number, to an external service for validation. If the webhook is configured, Commerce Cloud waits for the result of the validation to determine whether to submit the order.