Sep 16, 2016
Folks, this is a scam. First, the IRS will contact you by registered USPS mail to indicate issues with your taxes. And they will keep sending you mail until you respond. Second, IRS phone calls come from a local office which you will easily be able to see it's from a US Government office in your area.
They don't threaten you with jail, because they can't. They can arrest you for trying to evade taxes, but generally, you have to ignore them for a long time to get their. And they issue a warrant, not call you on the phone.
Just block the number, and file a complaint with the FTC. Impersonating a Federal official is a very high level felony, and the IRS is going after them hard. Here's a link on how to deal with these jerks:
https://www.irs.gov/uac/newsroom/irs-repeats-warning-about-phone-scams