Failure to furnish return: criminal penalties for willful non-filing subject to high-threshold and limited timely or low-tax exceptions. Willful failure to furnish a return of income where filing is required or mandated by notice is criminalised, with heavier imprisonment and fine where the non-filing would have involved substantial tax evasion and lighter imprisonment and fine in other willful non-filing cases. Prosecution is barred if the return is filed within one year from the end of the tax year (or within any alternate time under the return provision), or if, for non-corporate taxpayers, the assessed net tax after credits and withholdings does not exceed a specified low threshold.