If you’re convicted of tax evasion, you can go to jail. But because it has to go through the court system, the process will take time. The IRS also has to put a series of things into motion before they can pursue criminal prosecution. In some cases, the process will start with an audit of a filed tax return. The IRS will look for trends that may indicate a pattern of “willful evasion” over the course of several years and whether the erroneous amounts were significant. Most people will be prosecuted for tax evasion because of unreported income. They might have left out a considerable number of transactions or even entire sources of income.