Tax on updated return requires payment of tax, interest and additional levy before filing updated returns. Section 140B requires an assessee filing an updated return under section 139(8A) to pay, before filing, tax computed on the updated return after accounting for advance tax, TDS/TCS, specified reliefs and tax credits, together with interest, fees and an additional income-tax. The additional income-tax is 25% of aggregate tax and interest if filed within twelve months after the original due date, and 50% if filed after twelve but within twenty-four months; interest under sections 234A/B/C is specially computed for the updated-return context. The Board may issue implementatory guidelines.