Whether the accounting and purchasing functions are separate or combined, there should be a procedure in place to maintain control over all incoming invoices and bills, that enables you to know their status at all times, and to perform the necessary follow-up. It may be necessary to keep a log of all invoices received, and incoming invoices should be stamped with the date they are received. If an invoice turns out to be incorrect and needs to be returned to the vendor, this can be noted in the log.
Invoices for goods should be checked for the following:
Is the invoice valid?
Is the invoice original?
Is the vendor correct?
Has the invoice been altered in any way?
Has it already been paid?
Are quantities indicated on the invoice accurate as compared with the purchase order and receiving report?
Are the prices correct as compared with the purchase order?
Are the applicable taxes correctly calculated?
Is the total correct?
Are the payment terms or due date correct?
Has the invoice been approved by the designated person responsible for authorization of the disbursement?