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Internal controls

Accounts payable personnel must watch for fraudulent invoices. In the absence of a purchase order system, the first line of defense is the approving manager. However, AP staff should become familiar with a few common problems, such as " Yellow Pages " ripoffs in which fraudulent operators offer to place an advertisement. The walking-fingers logo has never been trademarked, and there are many different Yellow Pages-style directories, most of which have a small distribution. According to an article in the Winter 2000 American Payroll Association 's Employer Practices, "Vendors may send documents that look like invoices but in small print they state "this is not a bill". These may be charges for directory listings or advertisements. Recently, some companies have begun sending what appears to be a rebate or refund check; in reality, it is a registration for services that is activated when the document is returned with a signature."