The Internal Revenue Service (IRS) will never call you looking for personal information or payment information. They almost always initiate these conversations by sending notices through the mail.
In some specific instances an IRS agent might attempt to call or show up at your home or business, but this is AFTER several notices have been sent to the taxpayer by mail. If an agent comes in-person, they will have multiple forms of identification and credentials to verify their legitimacy. One of those documents is a what they call a HSPD-12 card. This is an official federal government ID card.
A more detailed image can be viewed here.
If you DO get a written notice in the mail, you ALWAYS have the opportunity to question or even appeal their findings. Knowing your rights as a taxpayer is important in these situations. For a quick reference, this link can be used to view the IRS Taxpayer Bill of Rights.
Of course, if you are in need of professional tax representation, our team at Buffalo Tax Strategies is available to help you Get Educated and Get Ahead!