Washington - The Treasury Department has a message for taxpayers getting calls from the IRS demanding immediate payment: Hang up.

Those aggressive, threatening calls are coming from phone scammers. And they are successful, too, costing more than 5,000 victims more than $26.5 million since October 2013. About 900,000 scammer contacts were reported during that period.

The callers fraudulently claim to be IRS officials and demand that taxpayers immediately send them payment. They often have some personal information about the person they’re calling and threaten criminal charges unless immediate payment is made.

“This scam has proven to be the largest of its kind that we have ever seen,” said J. Russell George, Treasury Department inspector general for tax administration. “It is critical that all taxpayers continue to be wary of unsolicited telephone calls and e-mails from individuals claiming to be IRS and Treasury employees.”... Read More: VIN