An IRS audit is generally an impartial review of your tax return to determine its accuracy. It is not an accusation of wrongdoing. But it is important to know that you, the taxpayer, generally have to substantiate the entries on your return. The IRS does not necessarily have to disprove anything. For example, if you gave $100 worth of old clothing to a charity but did not receive a receipt or have other proof that such a gift was made, you could be in trouble if you’re audited. If the IRS questions the deduction and you cannot provide proper evidence that a gift, in such amount, was made, the deduction may be disallowed.
However, generally for certain taxpayers (e.g., individuals) whose audit began after July 22, 1998, the burden of proof changes. The IRS will have the burden of proof if these taxpayers have credible evidence relating to most factual issues, have complied with all requirements, maintained required records, and have cooperated with all reasonable IRS requests for information. Keep in mind, the burden of proof does not change on a specific issue if another provision of the tax law requires a specific burden of proof with respect to that issue.