I don't believe you are understanding my question.  I'm not using the "Receipts" options, I'm using the DOCUMENT option- I'm simply taking a snap photo of my DOCUMENT through the mobile app, and adding it as a DOCUMENT to the customer just so that I can keep a copy of my materials invoices with the customer, until the time comes to invoice my customer - that way I have a copy of my vendor invoices that I have yet to bill my customer for all in one place.   (I do not want to automatically add receipts to my register, I have already manually posted the vendor invoice as a Bill in Quickbooks.)

My question is this - if I've attached a DOCUMENT to a "Customer" - is there a way to move that attachment from the "Customer" to my invoice as an attached document when I'm billing my customer?