-Unfilied tax returns fail to be filed for many reasons. The taxpayer must be aware that failure to file tax returns may be construed as a criminal act by the IRS. This type of criminal act is punishable by one year in prison for each year a tax return was not filed. The IRS may also file a “SFR” (Substitute For Return) Tax Returns for you. This is the IRS’s version of an unfiled tax return because SFR returns are filed in the best interest of the government with the only deductions you’ll see are standard deductions and one personal exemption. Regardless of what you have heard, you have the right to file your original tax return no matter how late it’s filed.