Attaching Files to Invoice Header Use this window to upload files required by the customer in the invoice header. Select Billing > Invoice Maintenance > Edit. The Billing Production Invoice page is displayed. Click . The Invoice Header Attachments window is displayed. Select the type of document in the Type field. Possible value: Default ForAllMandatory Select the Choose File option to attach the file in the Attach Document column. Click Validate. Note: You can view the list of files attached by the supplier in the Supplier Attachments section. You can delete an attached document using the Delete option.