Winneshiek County Sheriff's Deputies are warning the public of several reports of people calling taxpayers and impersonating IRS agents.
The scammers use several tricks, including a program that makes the IRS's toll-free phone number appear on the caller ID.
The callers say the taxpayer owes money and needs to pay by loading money on a prepaid card or by sending a wire transfer.
Deputies say the IRS alerts taxpayers of unpaid taxes through the mail.