Interest payable by Government on excess advance tax over assessed tax until date of regular assessment. The Central Government must pay simple interest when advance tax instalments exceed the amount of assessed tax; interest runs from the first April after the financial year to the date of regular assessment, with post year instalments attracting interest from payment. Refunds stop interest at the refund date; provisional assessments bar interest after provisional assessment. Subsequent orders that change the interest base increase or reduce interest accordingly, and reductions trigger a prescribed notice of demand by the Assessing Officer. Explanatory rules define assessed tax and treat certain reassessments as regular assessments.