What should you do if your accounts payable staff uncovers an old supplier invoice that has not been paid? Perhaps it was parked in someone’s “In” box, or maybe there was an extra invoice in the unpaid invoices file that does not appear in the open payables register. Whatever the reason, should you call the supplier to inquire further about the invoice?
Absolutely not. If you do that, one of three things happen: (1) the supplier tells you the invoice was cancelled, and not to worry about it (highly unlikely!), (2) the supplier realizes it has not been following up on unpaid invoices, and immediately blitzes your payables staff to ask when it will be paid, or (3) the supplier cancelled the invoice but now realizes it can get paid, so it badgers you for payment.
The trick is to minimize scenario 2, and to completely avoid scenario 3. To do so, call the supplier, tell them you are conducting an audit of open payables, and to fax over all unpaid invoices. If they don’t send over an invoice that matches the one you have found, then assume it was cancelled by the supplier, and throw it out. If they send one that matches your invoice, then quietly accelerate payment if it is overdue.