Invoice payment information is loaded into the PantherExpress system daily. You are able to find payment information going back to January 2017 in PantherExpress which includes the check number and payment date. The sharepoint article below provides you with an in depth guide to finding and understanding invoice payment information in PantherExpress.
https://www.ppt.pitt.edu/sites/default/files/pex_payment_status_updates.pdf