An IRS audit almost never starts the way people imagine it. The IRS makes first contact exclusively by mail, never by an unexpected phone call — any call claiming to be the IRS demanding immediate payment or threatening arrest is a scam, full stop. * The audit letter you'd actually receive identifies a specific item on your return the IRS wants to examine — a particular deduction, a credit claimed, or reported income that doesn't match what third parties reported to the IRS — along with the assigned agent's name and contact information. * Audits come in three forms with very different intensity levels. A correspondence audit happens entirely through the mail, usually focused on a single, narrow issue, and typically wraps up in 3 to 6 months. An office audit requires an in-person meeting at an IRS office and usually resolves faster, in 2 to 3 months. A field audit is the most involved: an IRS agent visits your home, business, or accountant's office, and these can stretch from 6 to 18 months depending on complexity. * Because the IRS needs time to process returns and run its selection algorithms, initial contact for an audit typically doesn't arrive until 12 to 24 months after you originally filed — which means an audit notice can show up long after you've mentally moved past that tax year. * Whatever the outcome — the IRS accepting your return as filed, or proposing changes to what you owe — you have the right to representation by yourself or an authorized professional throughout, and if you disagree with the findings, you can request review by the IRS's independent Office of Appeals rather than simply accepting the auditor's conclusion.