From the IRS website
https://www.irs.gov/uac/Newsroom/Phone-Scams- ... 6-Filing-Season
Most Importantly -
The IRS will never:
-Call to demand immediate payment, nor will the agency call about taxes owed without first having mailed you a bill.
-Demand that you pay taxes without giving you the opportunity to question or appeal the amount they say you owe.
-Require you to use a specific payment method for your taxes, such as a prepaid debit card.
-Ask for credit or debit card numbers over the phone.
-Threaten to bring in local police or other law-enforcement groups to have you arrested for not paying.
The article also contains links to where you can report and type of IRS scammers.
I got a recorded message from this number claiming to be the irs saying that I was committing tax fraud or evasion and they gave me this 305-504-2650 number and told me to call back or they would send the police to my house to arrest me.