The IRS may really, really want you to pay the money you owe to the government. But there are some lines even the taxman won’t cross -- like calling to shake you down for cash and sounding pretty darn mad about the whole thing. Scammers, however, are a different story.

Earlier this month, the IRS warned phony agents had conned some 1,100 people out of $5 million through harassing phone calls. And it appears the impostors are still at it, judging from a new alert the agency issued this week.

“These telephone scams are being seen in every part of the country, and we urge people not to be deceived by these threatening phone calls,” IRS Commissioner John Koskinen said in a statement. “We have formal processes in place for people with tax issues. The IRS respects taxpayer rights, and these angry, shakedown calls are not how we do business.”

How can you tell the difference between the fake IRS and the real IRS? Here are five things the agency says it will never, ever do:

1. Call you about taxes you owe without first mailing you an official notice.

2. Demand that you pay taxes without giving you the opportunity to question or appeal the amount they say you owe.

3. Require you to use a specific payment method for your taxes, such as a prepaid debit card.

4. Ask for credit or debit card numbers over the phone.

5. Threaten to bring in local police or other law-enforcement groups to have you arrested for not paying.

The IRS urges victims to report incidents to the Treasury Inspector General for Tax Administration