Although the IRS may select any tax return for an audit, there are a few circumstances that may cause the IRS to flag a return for an audit. For example, if your tax return numbers fall far outside the statistical norms – such as if you have abnormal deductions – you’re more likely to be audited.
Should someone with whom you have a business relationship have his or her return selected for an audit, this could trigger an audit of your return as well. If you make a mathematical mistake on your return, or if the income data you enter on your return doesn’t match what your employer sent to the IRS, you could be subject to an audit.
Additionally, the IRS will select returns for audits randomly. However, this is a rare occurrence. More commonly, the IRS picks a return for a specific reason.