Exclusion from sample scrutiny extended where returned income increases significantly and tax is paid before filing. Exclusion from sample scrutiny under section 143(4) is available where the later assessment year's returned income is at least thirty per cent higher than the prior year, both years' incomes exceed the basic exemption limit, the prior year's income does not exceed five lakh rupees, and tax for the later year is fully paid before filing; cases in the compulsory scrutiny basket are excluded from this relief.