This is a glimpse into an aspect of the 'how' of what we do.
For one of our wholesale/retail clients we implemented this digital workflow as a way to enter invoices through Xero and email them to our clients' customers:
It starts with the Client adding a record of all orders placed into a shared cloud folder. We're using dropbox for this particular client but we could use box.com or egnyte.com with just as much ease. Once the client has added the P.O.s or order sheets in .pdf format to our shared 'To Be Processed' shared cloud folder, we will go in 1x per week and add the details of the orders into Xero as Invoices. The Invoices will then be emailed to our clients' customers.
The P.O., entered into the system as an invoice is then attached to each transaction in Xero (Xero files). The P.O., once attached, can then be moved to an 'Invoiced' folder in dropbox, and the "To be processed" folder is empty and ready for the next batch the following week. This is a very simple, targeted way we offer invoice management.
Currently, our client wants the process as simple as possible, but even if they wanted an extra layer of approvals, we could still add the invoices into Xero as 'draft' and then it would be up to the client to login to Xero to review and approve/email themselves.
Either way works. Contact us to see if we can help you set up a similar system.