Money How far back can the IRS audit you? What to know about IRS audit triggers, letters and more March 2, 2023March 3, 2023Elisabeth Buchwald, USA TODAYComments Off on How far back can the IRS audit you? What to know about IRS audit triggers, letters and more If you receive an audit letter from the IRS don't ignore it. Respond in a timely manner to avoid paying fees.