OneDrive, Microsoft's file sync app formerly known as SkyDrive, lets you store your files online, edit Office documents in the free Office Web Apps, and easily access your online files from your PC.
Your payables lead sees missing receipts before bills come due, with the next owner named on the bill task.
Your bill reviewer sees the quantity gap or missing receipt ID on the task, so they can decide what to do with the supplier bill.
Your pending bill carries the corrected invoice with its earlier version linked when the match is clear.