It's 3, 6, 10, or many other options depending on the situation. They can be extended in various ways too... https://www.americanbar.org/groups/business_law/res

It's 3, 6, 10, or many other options depending on the situation. They can be extended in various ways too... https://www.americanbar.org/groups/business_law/resources/business-law-today/2017-august/irs-can-audit-for-three-years/ https://www.americanbar.org/groups/business_law/resources/bu...