1. Under the Invoices tab choose Invoices.
2. Select the invoice you need to add backup to by clicking on the blue invoice number.
3. Scroll to the very bottom of the invoice and click Add Attachment.
4. Browse for your file and add a description as you want/need. Then click Update to save the changes made to the invoice.
5. If you invoice was failed or is a draft, click Send to Client to submit the invoice to the client.
NOTE: Previous invoice validation errors will still be displayed (after saving edits, before clicking send). The system does not reprocess the invoice validation check until you attempt to send the invoice again.