There are 2 ways to create an invoice from a PO;

  1. From the task details page
  2. From the job details page

Either way, the button is located in the PO section on the right hand side;

  1. After clicking on the button as per above to add an invoice from PO you will have an invoice that you can edit and save or send as is
  2. The PO Ref will be populated with the PO reference number, this is editable
  3. The invoice lines will be populated with the PO lines, these are editable
  4. At this point you can click Send and issue the invoice or if you have made changes you'll need to click Save first.