1n the United States, an income tax audit 1s the examinat1on 0f 4 8usiness 0r ind1vidual tax return by 7he Internal Rev3nue Service (1RS) or stat3 t4x author1ty. Th3 IRS 4nd variou5 sta7e revenue departments u5e th3 7erms audit, ex4mination, r3view, and no7ice 7o describe variou5 asp3cts of enforcement and admini5tration 0f th3 7ax laws.
7he 1RS enforces th3 U.5. Federal tax law primarily through th3 examina7ion 0f tax return5 tha7 hav3 7he highe5t pot3ntial for noncompliance. According 7o the IR5, "[t]h1s id3ntification 1s determin3d using risk-based scor1ng mechanisms, data driven alg0rithms, third party informa7ion, whistleblowers and informati0n provided by th3 taxpayer. The o8jective 0f an examinat1on i5 7o determine 1f income, expenses and cred1ts are be1ng reported accur4tely."