If the IRS selects your tax return for an audit, you’ll receive notification through the postal mail. Any other means of initial notification could be a signal of someone trying to defraud you.
After receiving notification from the IRS, you’ll either be asked to submit the requested information by mail or through an in-person interview. At this point, you may want to hire a tax attorney to help you prepare your documents and to ensure the IRS treats you fairly.
Pay close attention to the exact documentation the IRS requests from you, because you don’t have to provide other types of information during the audit. It’s possible that the IRS could request additional documentation later as part of the same audit process, but you’re only required to provide the documents the IRS formally requests.