Many suppliers provide frequent deliveries and services, each one for small amounts of money. They tend to send large volumes of invoices, which can inundate the accounts payable staff. Also, given the high volume of invoices received, it is quite possible that some invoices will mistakenly be paid twice, especially if there are no invoice numbers that the computer system can check for duplicate payments.
One solution to these high-volume, low-cost invoices is to throw them all away; then, when the suppliers send the usual month-end statement of invoices outstanding, just record the statement in the computer system, using the statement date as the invoice number, and issue a single payment from that document. This also works well for the supplier, which receives just one check instead of many. The only problem with this approach occurs when the underlying invoices would normally be charged to different departments, which would require one to see the content of those invoices. However, in most cases, these invoices are so small that an incorrect or missing expense allocation would have little impact on departmental financial statements.