You can update the purchase order on a customer invoice after the invoice has been raise by following the below steps.
1. Click on ACCOUNTS DEPT.
2. Click on VIEW INVOICES
3. On the relevant invoice line you can click the below icon to set or change the PO for the invoice.
4. Set the number and you can then enter an email address you want to send update invoice to
5. Click on Send Email that will save the PO to the invoice and email a new copy.
