A system and method for identifying duplicate invoices among multiple systems, the method including the steps of loading first invoices having an index number into a database during a first predetermined time period; for each invoice having said index number, searching the database for another invoice, loaded during a second earlier time period, having the same index number and replacing the another invoice, if found, with said first invoice; comparing each first invoice for which no matching index number invoice was found with all other first invoices for which no matching index number invoice was found; comparing each of the first invoices for which no matching index number invoice was found with all the other invoices including the replaced invoices in the database; generating reports of the comparing steps, the reports listing invoices which compared; and eliminating from the database the first invoices deemed to have compared.