Instalments are due by 15 June (15%), 15 September (45%), 15 December (75%) and 15 March (100%) of the estimated tax. It mainly affects people with business income, capital gains, rent or large interest income not covered by TDS. Resident senior citizens without business income are exempt. Late payment attracts interest.
Finance glossary
What is Advance tax?
Income tax paid in instalments during the year, instead of in one go at the end, when your tax due exceeds ₹10,000.