An invoice received from a supplier shows the items purchased, the cost per unit, the total cost or extension of each item, and the total of all the items listed on the invoice.
A statement from a supplier lists all of the amounts owed on past invoices as of a specified date. For example, the statement from a supplier might indicate that as of July 31 your company owes for four invoices and a small amount from an earlier invoice.
It is possible that the statement amount is not the amount currently owed. For instance, it is possible that on July 30 and on August 3 your company actually paid for two of the invoices listed on the statement. For this reason it is a wise policy to make payments only from invoices and never from statements. This policy will avoid paying twice for an invoice amount.