Aggressive and threatening phone calls by individuals impersonating Internal Revenue Service agents top the IRS list of tax scams for the 2015 filing season. Don’t fall for it. Don’t give any information to them and no matter how mad, how aggressive they get? don’t give them your money.

The IRS said it has seen a surge in phone scams demanding immediate payment of taxes.

“If someone calls unexpectedly claiming to be from the IRS with aggressive threats if you don’t pay immediately, it’s a scam artist calling,” IRS Commissioner John Koskinen said in a statement. “The first IRS contact with taxpayers is usually through the mail. Taxpayers have rights, and this is not how we do business.”

The IRS also noted that scammers routinely alter caller ID numbers to make it look like the IRS is calling. They also press call recipients to divulge personal information over the phone.

The IRS said it never calls to demand immediate payment and never requires payment without the opportunity to appeal. It also does not demand a specific method of payment, ask for credit/debit card numbers over the phone or threaten to call in law enforcement if payment is not received.

More information on tax payments can be obtained by calling 800-829-1040. Scams can be reported online at tigta.gov or by calling 800-366-4484.