What legally constitutes proof of purchase if audited?
Proof of purchase needs to be proving legal entitlement to the use of the software installed. Most vendors will accept proof of purchase of software as purchase order details along with the matching invoice or receipt showing payment made. For products requiring a licence key then you also need to provide the applicable licence number or licensing certificate, serial number or other activation certification that was supplied when the software was purchased. This may also include emails from vendors if purchased online. If the product purchased is box copy (standalone copies of software) the licence number or serial number provided with the media is also required if the software has to be reinstalled at any stage.
