Adopt A Standard Invoice Numbering Convention

A major cause of duplicate payments is multiple copies of the same supplier invoice being entered in the computer system, but with slight variations on the invoice number that keep the computer from flagging them as duplicate invoices. This is an especially common problem when suppliers issue invoices with leading zeros, since one data entry clerk may enter the zeros, while another may ignore them. It is also common for employee expense reports and a variety of utility billings, since these documents have no invoice number. It also happens when an original invoice is not paid on time, so the supplier floods the company with extra copies of the invoice, hoping that one of the copies will eventually be paid.