On invoice rejections, have an option similar to the supplier statements to request a revision or resubmission. Having this in dext and the ability to send it to any email address for your contact would allow us to confirm that when an item is rejected it was requested to be corrected on a certain date, and sent to a certain user. This way when a vendor comes looking for payment we have all the details with the rejection and the vendor can attach the revision right to the original to be approved again.

Could also be applied to needed supplementary documentation such as insurance, statutory declarations, and any clearances required to release payment.