Per IRS: Selection for an audit does not always suggest there's a problem. The IRS uses several different methods:
- Random selection and computer screening - sometimes returns are selected based solely on a statistical formula. We compare your tax return against "norms" for similar returns. We develop these "norms" from audits of a statistically valid random sample of returns, as part of the National Research Program the IRS conducts. The IRS uses this program to update return selection information.
- Related examinations – we may select your returns when they involve issues or transactions with other taxpayers, such as business partners or investors, whose returns were selected for audit.
Next, an experienced auditor reviews the return. They may accept it; or if the auditor notes something questionable, they will identify the items noted and forward the return for assignment to an examination group.