Wilful failure to file income-tax returns attracts graded prosecution, with exceptions for timely filing and low tax liability. Wilful failure to furnish income-tax returns under Section 276CC covers returns under section 139(1), notices under sections 142(1)(i), 148 and 153A, fringe benefit returns, and returns under sections 115WD(1) and 115WH(2). The punishment depends on the tax sought to be evaded and differs for the period up to 28.02.2026 and from 01.03.2026. Exceptions exclude prosecution in specified cases, including old assessment years, timely filing within permitted limits, updated returns under section 139(8A), and small tax liability cases below Rs.10,000.