Advance tax revision: reassessment can change payable advance tax; taxpayers may send intimation or pay higher self-assessed tax. An AO may revise an order under section 210(4) if, after an order under subsection (3) but before March first of the relevant year, the assessee files a return for a later year or a later-year assessment is completed at a higher figure; on receipt of the revised order the assessee must pay advance tax accordingly. The assessee may instead submit a lower estimate by sending an intimation form to the Assessing Officer, or pay a higher self-estimated tax without intimation. Tax is computed on the total income of the later year at rates in force, less tax deducted at source.